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Ambient Air Quality Monitoring Report
Castlegar, British Columbia
Ministry of Environment
KOOTENAY REGION
ENVIRONMENTAL QUALITY
Ambient Air Quality Monitoring Report
Castlegar, British Columbia:
Particulate Matter - 1990 to 2007
Ministry of Environment
Kootenay Region
Ambient Air Quality Monitoring Report
Castlegar, British Columbia
Preface
Acknowledgements
The following report was prepared by Paul Willis and Robert Newell of the Ministry of
Environment. We would like to thank Chris Marsh, and Garry Bell, air technicians (Ministry of
Environment) responsible for maintaining the monitoring equipment, and further thanks to Julia
Beatty (Ministry of Environment), and Dr. Carl Schwarz (Simon Fraser University) for their
contributions to the report.
Cover Photos Courtesy of:
‘Pristine’ Castlegar: Ministry of Transportation
‘Hazy’ Castlegar: OurBC.com
ii
ENVIRONMENTAL QUALITY
The following report is one in a series of air quality reports being issued by the Kootenay
Regional Office for all communities in the region where air quality is monitored. The intention
of the Regional Office of the Ministry of Environment is to publish air quality reports on our
website (http://www.env.gov.bc.ca/epd/regions/kootenay/aq_reports/index.htm) to provide the
information to industry and local government, other stakeholders and the public at large. By
providing such information in a readily understood format, the Ministry of Environment hopes
local environmental quality conditions can be better understood, and better decisions regarding
air quality management can be made.
Ambient Air Quality Monitoring Report
Castlegar, British Columbia
Ambient Air Quality Monitoring Report
Castlegar, British Columbia
Prepared by:
Ministry of Environment
Environmental Quality Section
205 Industrial Road G
Cranbrook, B.C.
V1C 6H3
August, 2008
iii
ENVIRONMENTAL QUALITY
Particulate Matter - 1990 to 2007
Ambient Air Quality Monitoring Report
Castlegar, British Columbia
Executive Summary
The Castlegar airshed refers to an air mass which extends through the valley system surrounding
the confluence of the Columbia River and the Kootenay River. The airshed extends
approximately 15 km either side of the Kootenay and Columbia rivers and 30 km along each
valley axis. In addition, the Castlegar airshed extends approximately 20 km north into the
foothills of the Selkirk Mountain Range. The Selkirk Mountain Range surrounds Castlegar and,
thus, heavily influences the containment and dispersion of air pollutants within the airshed.
PM in Castlegar currently is monitored by a device known as a “Partisol” manual sampler 1 . The
device was located on top of the Castlegar Fire Hall. The sampler and devices like this Partisol
have been used for air quality monitoring purposes since 1990. Air quality data is extrapolated
from analysis of air filters collected from the Partisol system. Collection of filters is conducted
on six-day cycle ensuring that data is produced for every day of the week (i.e., Tuesday,
Monday, Sunday, etc.).
The air quality monitoring program has been in place in Castlegar for approximately 18 years
(since 1990), allowing air quality trends in the Castlegar airshed to begin to emerge. Data
indicates that Castlegar’s PM levels have decreased in recent years from the early 1990s. Mean
annual PM concentrations exceeded the World Health Organization objective of 20 μg/m3 for the
majority of the first half of the 1990s; however, yearly PM means have not exceeded the
objective in over a decade. Furthermore, the most recent year of air quality monitoring (2007)
produced one of the lowest PM means observed during the 18-year monitoring period. In
addition, health indicators such as exposure levels have decreased dramatically over the last 18
years. Whether PM concentrations and health indicators will continue to decrease is uncertain;
however, the decrease in PM and health indicators from the first five years of the monitoring
program to the last five years of monitoring is apparent.
PM in Castlegar originates from many sources including fugitive dust from traffic, woodstove
smoke, industrial emissions, slash burning activities, and forest fires. The extent a source of PM
might impact the Castlegar airshed depends on many factors, such as the time of the year. For
example, PM generated from vehicular traffic could increase during months of high tourism.
1
A manual sampler is an air sampler that does not have automated mass measurement and communication
capabilities.
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Ministry of Environment
Kootenay Region
ENVIRONMENTAL QUALITY
A vast amount of evidence exists to support the concern that airborne particulate matter (PM)
poses a significant health risk to humans. In response to such a concern, the Ministry of
Environment (MoE) has implemented air quality monitoring programs in various communities
throughout British Columbia. The following report provides an assessment of the results of the
monitoring program established in the Castlegar airshed. The report was prepared by the MoE in
an effort to inform the public, local government, and industry on the air quality conditions within
the Castlegar airshed based on PM data collected during the years of 1990 to 2007. The purpose
of the report is to provide insight on how to effectively manage the local air quality conditions of
Castlegar.
Ambient Air Quality Monitoring Report
Castlegar, British Columbia
ENVIRONMENTAL QUALITY
The MoE has compared data collected from the Castlegar airshed monitoring program (from
1990 to 2007) with air quality standards used in British Columbia and, currently, Castlegar
airshed does not appear to be a major concern in terms of ambient air PM concentrations.
However, air quality monitoring will continue in the Castlegar airshed on a routine frequency, to
ensure we understand whether PM levels continue to remain below B.C. air quality objectives.
A “safe” level of exposure for PM does not exist, meaning PM impacts public health even at low
levels. So although PM levels in Castlegar comply with provincial air quality objectives, the
public, government and industry should be constantly cooperating and striving to improve air
quality within the Castlegar airshed.
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Ministry of Environment
Kootenay Region
Ambient Air Quality Monitoring Report
Castlegar, British Columbia
Table of Contents
Preface ................................................................................................................................ ii
Executive Summary ......................................................................................................... iv
2.0 Air Quality Objectives/Standards ............................................................................. 5
2.1 Provincial Objectives ............................................................................................... 5
2.1.1 Air Quality Index ............................................................................................... 5
2.2 National Ambient Air Quality Objectives (NAAQOs) ............................................. 5
2.2.1 Reference Levels ................................................................................................ 6
2.2.2 Exposure Estimates ............................................................................................ 6
2.3 Canada-wide Standards (CWS) Agreement.............................................................. 6
2.4 Comparison of Federal and Provincial Air Quality Criteria ..................................... 7
2.5 World Health Organization (WHO) Objective ......................................................... 8
3.0 Air Quality Monitoring in Castlegar ....................................................................... 9
4.0 Airshed Description ................................................................................................. 11
4.1 Influences on Air Quality: Emissions .................................................................... 12
4.1.1 Provincial Overview ........................................................................................ 12
4.2 Influences on Air Quality: Weather and Terrain ................................................... 15
5.0 Air Quality in Castlegar .......................................................................................... 19
5.1 Results and Trends .................................................................................................. 20
6.0 Conculsions and Recommendations ........................................................................ 28
For More Information .................................................................................................... 30
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Ministry of Environment
Kootenay Region
ENVIRONMENTAL QUALITY
1.0 Introduction ................................................................................................................. 1
1.1 Particulate Matter and Health Effects ...................................................................... 3
Appendices ....................................................................................................................... 31
Appendix A - Glossary and Abbreviations ................................................................... 31
Appendix B – NAAQO Exposure Calculations............................................................ 37
Appendix C - Central Tendency and Statistical Significance ....................................... 38
Appendix D - ANOVA Tests ........................................................................................ 41
Appendix D1 - ANOVA Applied to Yearly Data ......................................................... 42
Appendix D2 - Two-Way ANOVA Applied to City Comparisons .............................. 43
Appendix D3 - ANOVA Applied to Monthly Data ...................................................... 44
Appendix D4 - ANOVA Applied to Day of Week Data .............................................. 45
Appendix D5 - Two-Way ANOVA Applied to 2007 Comparison with 1990 to 2006 46
Appendix E - G-Test Statistics ..................................................................................... 47
Appendix F - Yearly PM Comparisons to Objective .................................................... 48
Appendix G1 PM Air Quality Sampling in Castlegar .................................................. 50
Appendix G2 Air Quality Sampling and Parameters in Kootenay Region .................. 51
Appendix H1 - PM10 Data for 1990 .............................................................................. 54
Appendix H2 - PM10 Data for 1991 .............................................................................. 55
Appendix H3 - PM10 Data for 1992 .............................................................................. 56
Appendix H4 - PM10 Data for 1993 .............................................................................. 57
Appendix H5 - PM10 Data for 1994 .............................................................................. 58
Appendix H6 - PM10 Data for 1995 .............................................................................. 59
Appendix H7 - PM10 Data for 1996 .............................................................................. 60
Appendix H8 - PM10 Data for 1997 .............................................................................. 61
Appendix H9 - PM10 Data for 1998 .............................................................................. 62
Appendix H10 - PM10 Data for 1999 ............................................................................ 63
Appendix H11 - PM10 Data for 2000 ............................................................................ 64
Appendix H12 - PM10 Data for 2001 ............................................................................ 65
Appendix H13 - PM10 Data for 2002 ............................................................................ 66
Appendix H14 - PM10 Data for 2003 ............................................................................ 67
Appendix H15 - PM10 Data for 2004 ............................................................................ 68
Appendix H16 - PM10 Data for 2005 ............................................................................ 69
Appendix H17 - PM10 Data for 2006 ............................................................................ 70
Appendix H18 - PM10 Data for 2007 ............................................................................ 71
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Ministry of Environment
Kootenay Region
ENVIRONMENTAL QUALITY
Ambient Air Quality Monitoring Report
Castlegar, British Columbia
Ambient Air Quality Monitoring Report
Castlegar, British Columbia
Figure 1. Relative sizes of particulate matter..............................................................2
Figure 2. Air quality monitoring sites in Kootenay Region........................................9
Figure 3. Partisol sampler in Castlegar .....................................................................10
Figure 4. Map of Castlegar airshed ...........................................................................11
Figure 5. Human-caused sources of inhalable particulate matter (PM10) ................13
Figure 6. Human-caused sources of respirable (fine) particulate matter
(PM2.5) .....................................................................................................14
Figure 7. Daily airflow within valleys ......................................................................16
Figure 8. Thermal stratification resulting from temperature inversion.....................17
Figure 9. Annual cycle of mixing heights at Castlegar airshed ................................18
Figure 10. Comparison of particulate matter concentrations between various B.C.
communities ............................................................................................21
Figure 11. Particulate matter data compared with previous years ............................22
Figure 12. NAAQO exposure in Castlegar ...............................................................23
Figure 13. NAAQO exposure comparison between Castlegar, Golden, Nelson ......24
Figure 14. Percentages of days in a month with values exceeding NAAQ
objective ..................................................................................................25
Figure 15. PM10 in Castlegar airshed by month ........................................................26
Figure 16. PM10 in Castlegar airshed by day of week ...............................................27
Figure A1. Histogram of Castlegar PM10 data distribution.......................................38
Figure A2. Histogram of the natural logarithm of Castlegar PM10 data ...................39
Figure A3. Annual variation of the mean and range of PM10 in Castlegar ...............40
Figure A4. Yearly PM10 values compared to air quality objective ...........................48
Table 1. Comparison of provincial and federal air quality criteria .............................7
Table 2. World Health Organization (WHO) objectives for PM ................................8
Table 3. Summary of annual PM10 in Castlegar from 1990 to 2007 .......................19
Table A1. Results from z- test analysis applied to yearly data .................................49
Table A2 Dates and types of the PM monitoring programs in Castlegar .................50
Table A3 Dates and parameters measured at Kootenay Region air quality
monitoring sites.......................................................................................51
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Ministry of Environment
Kootenay Region
ENVIRONMENTAL QUALITY
Figures and Tables
Ambient Air Quality Monitoring Report
Castlegar, British Columbia
1.0 Introduction
Many pollutants are known to have detrimental effects on human and environmental
health. The common ones monitored in B.C. are: nitrogen dioxide, sulphur dioxide, total
reduced sulphur, carbon monoxide, ozone, formaldehyde, and PM. However, in most
Kootenay Region communities, including Castlegar, PM is the most serious health
concern. As such, this was our primary monitoring focus and this report will deal only
with the assessment of PM.
“Particulate matter” may sound like a scientific expression, but it breaks down into
simple concepts. Particulates are tiny solid or liquid particles that come in many shapes
and sizes, and are from many different sources.
The majority of particulates that have a negative effect on human health are 10
micrometres or less in diameter (PM10). A micrometre (µm) is a millionth of a metre, so
PM10 is roughly the same size as bacteria. Like bacteria, PM10 is invisible to the naked
eye and small enough to be inhaled into our lungs.
Figure 1 demonstrates that PM comes in
a wide range of sizes and differs in
chemical composition and source.
Collectively, PM10 includes the coarse
fraction (PM10-2.5), the fine fraction
(PM2.5-0.1), and the ultra-fine fraction
(PM<0.1).
Fine particulate matter is
small enough to enter our
airways and lungs as we
breathe.
The fine fraction (PM2.5) comprises of particles smaller than 2.5 µm that generally are
formed by chemical reactions. PM2.5 often is generated directly through combustion or
burning; however, PM2.5 also may be created indirectly from reactions in the atmosphere
(secondary PM). Common sources of PM2.5 include smoke from burning of yard waste,
2
A geographic area that, because of topography, meteorology, and/or climate, is frequently affected by the
same air mass.
1
Ministry of Environment
Kootenay Region
ENVIRONMENTAL QUALITY
There is mounting evidence that airborne particulate matter or PM, poses a significant
health concern prompting the Ministry of Environment (MoE) to institute a network of
monitoring for PM. The data resulting from the monitoring has been compiled and
analysed by the MoE for this report to inform the public, local government, and industry
about PM levels in the Castlegar airshed 2 . This document will also discuss trends in air
quality data and factors that have possibly influenced the levels of PM measured in the
community. By providing this information it is hoped that local air quality conditions can
be better understood and decisions regarding air quality management will be well
informed.
Ambient Air Quality Monitoring Report
Castlegar, British Columbia
slash burning, residential woodstoves, exhaust from automobiles, and industrial smoke
stacks. In addition to sources associated with human activities, PM2.5 is also generated
through natural processes such as forest fires.
Figure 1: Relative sizes of particulate matter.
The coarse fraction consists of particles between 2.5 µm and 10 µm in diameter.
Particles of this size often assume the form of fugitive dust, which consists of finely
ground rock and clay, and come from both human and natural sources. The most
common source of fugitive dust caused by human activity is unpaved roads, or paved
roads that have had sand and salt applied for winter travelling. In spring, when the roads
are no longer frozen or wet, traffic grinds up the gravel into finer and finer particles.
These are then either thrown into the air by passing traffic, or picked up by strong winds.
Other sources of coarse fraction PM include industrial emissions (e.g., fly-ash) and sea
salt. Depending on meteorological conditions, it is possible for the particles to stay
suspended for hours or days, resulting in poor air quality. Natural sources of fugitive
dust are river, lake, and reservoir banks and dust storms, problems that affect
communities like Castlegar when water levels are low.
2
Ministry of Environment
Kootenay Region
ENVIRONMENTAL QUALITY
Secondary PM is formed through atmospheric reactions involving oxides of nitrogen,
sulphur dioxide, volatile organic compounds, and/or ammonia from natural (e.g., tree
metabolism, wildfires) or human-caused emissions (e.g., industrial processes, vehicles).
High concentrations of secondary PM can produce an effect known as blue haze. Blue
hazes impair visibility of scenic landscape and can be economically detrimental to
communities with high tourism such as Castlegar. Secondary PM of the fine fraction
may remain suspended in the atmosphere for extended periods of time (depending on
meteorological conditions) resulting in prolonged periods of poor air quality.
Ambient Air Quality Monitoring Report
Castlegar, British Columbia
1.1 Particulate Matter and Health Effects
Two types of PM exist that produce adverse health effects in people: inhalable PM and
respirable PM. Inhalable particulate matter, also known as PM10, is composed of
particles small enough to be carried into our airways. However, some of these particles
are large enough to get trapped in the larger airways and do not reach the smallest
cavities within our lungs. Respirable particulate matter consists of the fine and ultrafine fractions of PM (also termed as PM2.5) and is composed of particles small enough to
travel into the deepest parts of our lungs.
PM can cause a range of health effects in people, from annoying symptoms such as a
runny nose to increased premature mortality in extreme cases. Recent studies have
associated PM with longer-term health effects such as lung cancer.
Based on evidence from epidemiological studies, the effects of exposure to PM10 and
PM2.5 concentrations are reflected in:
¾ Increases in mortality due to cardiorespiratory diseases.
¾ Increases in hospitalization due to cardiorespiratory diseases.
¾ Decreases in lung function in children and asthmatic adults.
¾ Increases in respiratory stresses that can
lead to absenteeism from work or school
and a restriction in activities.
¾ Chronic effects including increased
development of chronic bronchitis and
asthma in some adults, and reduced
survival.
Particulate matter can
cause a range of
effects … from
annoying symptoms to
premature mortality.
Those most susceptible to PM-related health impacts are children, the elderly, asthmatics,
and people with pre-existing cardiorespiratory diseases.
3
Ministry of Environment
Kootenay Region
ENVIRONMENTAL QUALITY
PM is the air pollutant of greatest concern in the Castlegar airshed and throughout the
Kootenay Region. There are two main reasons for the concern over this pollutant: 1)
these particles are small enough to enter our airways and lungs as we breathe, and 2) the
emission sources typically found in interior B.C. tend to produce significant amounts of
PM.
Ambient Air Quality Monitoring Report
Castlegar, British Columbia
ENVIRONMENTAL QUALITY
Previous medical studies have determined that no apparent safe lower threshold for
adverse health effects exists for PM 3 . Such a finding has prompted governments to
review and strengthen air quality criteria for PM in order to reduce the risks to
Canadians 4 .
3
http://www.healthservices.gov.bc.ca/pho/pdf/phoannual2003.pdf
WGAQOG (1999) National Ambient Air Quality Objectives for Particulate Matter. Part 1: Science
Assessment Document. A report by the CEPA/FPAC Working Group on Air Quality Objectives and
Guidelines. Minister, Public Works and Government Services.
4
4
Ministry of Environment
Kootenay Region
Ambient Air Quality Monitoring Report
Castlegar, British Columbia
2.0 Air Quality Objectives/Standards
To evaluate air quality, objectives and standards have been introduced that provide what
are considered to be acceptable levels of PM10 and PM2.5 in British Columbia.
2.1 Provincial Objectives
More recent health evidence suggests that PM2.5 poses a greater health risk than do the
coarser fractions. In response to this concern, the MoE has established (in the spring of
2008) an air quality objective for PM2.5 of 25 µg/m3 (24-hour average) 6 .
2.1.1 Air Quality Index
The air quality index (AQI 7 ) is the most familiar indicator of air quality to British
Columbians, providing the public with a meaningful measure of outdoor air quality via
daily reports available on the Internet. It is determined by comparing air quality
measures for contaminants such as ozone, carbon monoxide, and PM to levels established
by the federal or provincial governments. In provincial AQI calculations, PM10 levels are
compared to reference levels of 25, 50, and 100 µg/m3 (comparable to provincial
reference Levels A, B and C, respectively).
The data analysis of this report uses the reference levels of the AQI system to count the
number of days in a year that each level is exceeded and reports the percentage of days
that each level is exceeded. Along with these guidelines, British Columbia also
references other national standards described below.
2.2 National Ambient Air Quality Objectives (NAAQOs) 8
5
For more information about NAAQO, see: http://www.hc-sc.gc.ca/ewh-semt/alt_formats/hecssesc/pdf/pubs/air/naaqo-onqaa/particulate_matter_matieres_particulaires/summary-sommaire/98ehd220.pdf
6
Air quality objectives established by MoE in the spring of 2008 are currently in the review phase among
provincial stakeholders and are subject to change.
7
A numerical index of particulate matter, ozone and other common air pollutants. From the AQI, we can
effectively rate air quality as “Good”, “Fair”, “Poor”, or “Very Poor”. For guidance on how to calculate
the AQI, see http://a100.gov.bc.ca/pub/aqiis/air.info.
8
National Ambient Air Quality Objectives: http://www.hc-sc.gc.ca/ewh-semt/pubs/air/naaqo-onqaa/indexeng.php
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Ministry of Environment
Kootenay Region
ENVIRONMENTAL QUALITY
Recognizing the threat that PM10 poses to human health, the MoE established an air
quality objective for PM10 of 50 µg/m3 (24-hour average) in 1995. This level is
comparable to the maximum acceptable level in the National Ambient Air Quality
Objective (NAAQOs) system 5 or a provincial Level B objective.
Ambient Air Quality Monitoring Report
Castlegar, British Columbia
The NAAQOs identify benchmark levels of protection for people and the environment.
NAAQOs guide federal, provincial, territorial and regional governments in making riskmanagement decisions, playing an important role in air quality management. Permitting
of local emission sources, air quality index calculations, and the development of
provincial objectives all make use of the NAAQOs.
The NAAQO system defines three objectives: a maximum desirable level, a maximum
acceptable level, and a maximum tolerable level. With the exception of the maximum
tolerable objective, the NAAQOs are viewed as effects-based, long term air quality goals
determined by statistical analysis of reported epidemiological effects.
Although negative health effects can occur at any level of PM, the CEPA/FPAC 9
Working Group on Air Quality Objectives and Guidelines recommended reference levels
of 25 µg/m3 (24 hour average) for PM10 and 15 µg/m3 (24 hour average) for PM2.5. These
levels were intended to represent estimates above which there are demonstrated (i.e.,
statistically significant) effects on human health and the environment. They were not
intended to be used as enforceable air quality objectives, but as the basis for establishing
goals for long-term air quality management. 10
2.2.2 Exposure Estimates
Risk to human health is believed to increase linearly with PM concentrations. Hence, a
simple estimate of exposure, and therefore risk, can be estimated by summing the
concentration above a threshold or reference level over a specific period of time. The
method used in this report to calculate exposure is explained in Appendix B.
2.3 Canada-wide Standards (CWS) Agreement
Under the Canada-wide Accord on Environmental Harmonization, the Canadian
Environment Ministers (with the exception of Quebec) ratified the Canada-wide
Standards (CWS) for PM and ozone in July 2000 11 . The CWS process is expected to
provide new tools for the management of environmental issues of national interest.
The standards for particulates are based on daily average PM2.5 measurements over three
consecutive calendar years. The 98th percentile is often used in analyses and
comparisons because it reduces the bias caused by a single extremely high reading. For
9
Canadian Environmental Protection Act Federal-Provincial Advisory Committee
CEPA/FPAC Working Group on Air Quality Objectives and Guidelines (1999) National Ambient Air
Quality Objectives for Particulate Matter. Part 1: Science Assessment Document. Minister, Public Works
and Government Services.
11
Canada-wide Standards Agreement: http://www.ccme.ca/ourwork/air.html?category_id=99
10
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Ministry of Environment
Kootenay Region
ENVIRONMENTAL QUALITY
2.2.1 Reference Levels
Ambient Air Quality Monitoring Report
Castlegar, British Columbia
each year, the 98th percentile of the daily averages is determined and then averaged for
the last three calendar years. This value, referred to in this report as the CWS Indicator,
can then be compared to the standard and to other communities.
The adopted standard for PM2.5 is 30 µg/m3. Although there was no standard or objective
set by the CWS for PM10, the previously described “CWS Indicator” is used to analyze
historical trends in ambient air quality in this report. 12
Three reference levels (A, B, and C) have been defined in B.C. for PM10 based on the
NAAQO system of the federal government (see Table 1). Achieving Level A
concentrations (less than 25 μg/m3) creates an atmosphere of good air quality where
humans and environment can flourish. Subscribing to Level B concentrations (25 to 50
μg/m3) will provide sufficient protection for the health of the majority of individuals but
may allow discomfort to occur in sensitive individuals. At Level C concentrations (50 to
100 μg/m3), risks to human health become more severe, and concentrations of PM must
be reduced to adequately protect human health.
Table 1. Comparison of provincial and federal air quality criteria.
The AQI rating (in the above table) converts the concentrations of PM10 pollutants to a
common-language, unit-less scale to indicate health implications. To clarify, threshold
levels of PM10 are identified by describing what the quality of ambient air in a day would
be if said threshold is surpassed. For example, if the average PM10 concentration
throughout a day is below 25 μg/m3, the day is described to have “good” air quality (in
terms of PM10). However, if the day experienced a higher average PM10 above 50 μg/m3,
12
The B.C provincial government has an objective for PM10, and the federal government has a standard for
PM2.5. but there is no common objective or standard for both pollutants.
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Ministry of Environment
Kootenay Region
ENVIRONMENTAL QUALITY
2.4 Comparison of Federal and Provincial Air Quality
Criteria
Ambient Air Quality Monitoring Report
Castlegar, British Columbia
PM10 would have exceeded both the “good” and “fair” thresholds, and the day is
considered to be of “poor” air quality.
2.5 World Health Organization (WHO) Objectives
WHO has defined long term objectives for both coarse PM and fine PM. To minimize
health issues related to PM, WHO recommends maintaining average yearly fine PM
levels at concentrations below 10 μg/m3. Similarly, WHO recommends yearly averages
of coarse PM should not exceed 20 μg/m3. The coarse and fine PM objectives defined by
WHO are used in the current report for statistical analysis to determine whether yearly
PM means exceed objectives (see Appendix F). The current report only makes use of the
coarse PM objective (20 μg/m3) because the report analyzes long term trends in coarse
PM but does not examine trends in fine PM.
Table 2. World Health Organization (WHO) objectives for PM.
13
For more information on WHO air quality objectives, refer to
http://whqlibdoc.who.int/hq/2006/WHO_SDE_PHE_OEH_06.02_eng.pdf
8
Ministry of Environment
Kootenay Region
ENVIRONMENTAL QUALITY
The PM targets defined by NAAQO are useful in determining whether daily averages of
PM are complying with air quality objectives. However, when examining the long term
trends in ambient air PM concentrations, air quality data is converted to yearly means
(rather than using daily means for trend analysis). NAAQO PM target levels are intended
for daily average values and are not applicable to yearly mean values; therefore, yearly
means are compared to air quality objectives designed by the World Health
Organization (WHO) 13 .
Ambient Air Quality Monitoring Report
Castlegar, British Columbia
3.0 Air Quality Monitoring in Castlegar
To characterize PM levels in B.C., MoE has been monitoring PM levels throughout the
province for a number of years. Figure 2 displays the locations where air quality
monitoring is done in the Kootenays, and the types of pollutants sampled. While the
earliest monitoring dates back to the early 1970’s, the large-scale monitoring effort began
in 1989.
Figure 2. Air quality monitoring sites in Kootenay Region.
The locations identified depict all operating air quality in the Kootenay Region stations
on January 1, 2006.
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Ministry of Environment
Kootenay Region
ENVIRONMENTAL QUALITY
PM levels are measured to determine the exposure concentrations of people in B.C.
communities. Monitoring enables regulators and policymakers to identify the air quality
impacts of current sources and determine the impacts of new sources or emission control
measures. Monitoring over long periods of time allow communities to assess trends that
will show if air quality is getting better or worse. In addition, long term monitoring
allows comparison with standards and objectives to assess how Castlegar’s air quality is
doing in relation to health standards. Comparisons can also be done between the air
quality in Castlegar and in other B.C. communities where air quality is monitored.
Ambient Air Quality Monitoring Report
Castlegar, British Columbia
The air quality monitoring station is located on the roof the Fire Hall within Castlegar
(see Figure 2). Coarse particulate matter has been monitored from this rooftop location
and a nearby senior centre since 1990. The data available for analysis in the current
report was collected during the interval of 1990 to 2007, so this report discusses PM10
trends occurring in Castlegar over an 18-year period. A PM2.5 (fine fraction) monitoring
program has not yet been implemented in Castlegar.
Figure 3. Partisol sampler in Castlegar.
The images show the Partisol manual sampler located on the Fire Hall of Castlegar.
10
Ministry of Environment
Kootenay Region
ENVIRONMENTAL QUALITY
Air quality in the Castlegar airshed is monitored using a manual, non-continuous air
sampler (Figure 3). Manual samplers draw air at a predetermined flow rate through a
filter of known mass. Air is drawn through the filter over a duration specified by the
operator of the sampler (duration is usually 24 hours). After air passes through a filter,
the filter is removed from the sampler and analyzed in a laboratory setting. Ambient PM
concentrations are calculated by dividing the gain in filter mass (after air has passed
through the filter) by the product of sampling period and sampling flow rate. Different
fractions of particulate matter (i.e., coarse and fine) can be localized on filters through the
use of varying sizes of sampling head inlets. Chemical composition of particulate matter
may be determined through additional analyses of the filters; however, such analyses are
not performed on a routine basis.
Ambient Air Quality Monitoring Report
Castlegar, British Columbia
4.0 Airshed Description
ENVIRONMENTAL QUALITY
Generally speaking, an airshed is a body of air affected by any source of air pollutant or
emission within (or associated with) the air mass. For example, a Castlegar resident
burning their yard waste will exert an effect (i.e., increase PM concentrations) within the
Castlegar airshed but likely will not affect air quality in Nelson or Grand Forks. For the
purposes of airshed management, the Castlegar airshed extends approximately 15 km
either side of the Kootenay and Columbia Rivers and 30 km along each valley axis. The
airshed also includes a valley area directly north of Castlegar extending approximately 20
km (see Figure 4). The Castlegar airshed is bound roughly by the mountainous terrain
that defines the valley region.
Figure 4. Map of Castlegar airshed. The Castlegar airshed is bounded roughly by the
mountainous terrain surrounding Castlegar.
11
Ministry of Environment
Kootenay Region
Ambient Air Quality Monitoring Report
Castlegar, British Columbia
4.1 Influences on Air Quality: Emissions
4.1.1 Provincial Overview
Though provincial summaries may not reflect relative source contributions in individual
communities such as Castlegar, they are useful as benchmarks for comparison. For both
PM10 and PM2.5, the contributions from area sources 16 (e.g., fireplaces, wood stoves and
backyard burning), mobile sources (e.g., diesel trucks), and road dust are important to
local air quality. Area sources are numerous and/or widespread and are located in close
proximity to where we live. Point sources 17 of PM in the region include industrial
operations, such as wood and pulp mills.
As summarized in Figures 5 and 6, these are the key points from the 2000 Emissions
Inventory with regard to PM in the B.C. Interior:
PM10
¾ Point sources contribute 45% of PM10 emissions, with 23% coming from the
wood industry and 11% coming from the pulp and paper industry.
¾ Area sources are collectively responsible for 46% of PM10 emissions; 25% are
from prescribed burning, 11% are from agricultural practices and 9% are from
residential fuel wood combustion.
PM2.5
¾ Area sources account for almost half (49%) of PM2.5 emissions, with significant
contributions from prescribed burning (33%) and residential fuel wood
combustion (13%).
¾ Point sources contribute 40% of PM2.5 emissions, with 20% from the wood
industry and 12% the from the pulp and paper industry.
14
MWLAP (2004) 2000 Emissions Inventory Analysis Report. Note that the estimates contained
in this report include neither natural sources such as wildfires and biogenic emissions, nor
fugitive road dust.
15
Primary pollutants are the chemicals that are emitted directly into the atmosphere. Secondary pollutants
are the result of primary pollutants reacting chemically or physically to form different compounds.
16
An emission source of pollutants that covers a large, and sometimes poorly defined, area.
17
An emission source of pollutants that remains in a small identifiable area.
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Ministry of Environment
Kootenay Region
ENVIRONMENTAL QUALITY
The sources of PM vary from community to community and from season to season.
Based on the year 2000 provincial emissions inventory 14 , an estimated 850 thousand
tonnes of PM were released into the atmosphere as primary pollutants 15 . Note that this
estimate is only for emissions that result from human activities (i.e., anthropogenic
emissions).
Ambient Air Quality Monitoring Report
Castlegar, British Columbia
Figure 5. Human-caused sources of inhalable particulate matter (PM10)
The figure displays information for areas outside the Lower Mainland, and exclude
natural sources, such as wildfires or biogenic emissions, and fugitive road dust.
Source: 2000 Emissions Inventory Analysis Report, MWLAP. 2004.
18
Particles that are not directly emitted into the atmosphere, but are produced by chemical and physical
processes. See Appendix A: Secondary Pollutant.
18
Lowenthal D.H., D. Wittorff, and A.W. Gertler (1994) CMB Source Apportionment During REVEAL Final Report. Air Resources Branch, British Columbia Ministry of Environment, Lands and Parks.
20
Pryor S.C. and D. Steyn (1994) Visibility and ambient aerosols in south-western British Columbia during
REVEAL. British Columbia Ministry of Environment, Lands and Parks.
21
ARB (1994) 1990 British Columbia Emissions Inventory of Common Air Contaminants, Air Resources
Branch, British Columbia Ministry of Environment, Lands and Parks, Victoria, B.C., December.
22
“Biogenic” sources are a subset of natural sources and include only those sources that result from
biological activity. Biogenic emissions represent a significant portion of the natural source emissions.
VOC, NOx, and the greenhouse gases can all be emitted from biogenic sources.
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Ministry of Environment
Kootenay Region
ENVIRONMENTAL QUALITY
Secondary particles 18 were not considered in the emissions inventory estimates,
although studies limited to the Lower Fraser Valley indicate that they may comprise up to
50% of the fine PM collected during the summer. Sulphur dioxide (SO2), nitrogen oxides
(NOx), various hydrocarbons, and ammonia (NH3) are important gases involved in the
formation of secondary particles 19,20 . Major sources of SO2 include the cement, pulp and
paper, and petroleum industries, as well as motor vehicles 21 . Approximately 75% of NOx
emissions in the Lower Mainland are from motor vehicles and marine vessels. Motor
vehicles, solvent usage and vegetation 22 contribute to over 70% of hydrocarbon
emissions. Agricultural use of fertilizers is the dominant source of NH3.
Figure 6. Human-caused sources of respirable (fine) particulate matter (PM2.5)
The figure displays information for areas outside the Lower Mainland, and exclude
natural sources, such as wildfires or biogenic emissions, and fugitive road dust.
Source: 2000 Emissions Inventory Analysis Report, MWLAP. 2004.
Figures 5 and 6 depict general models for relative contributions of PM emission sources
in B.C. airsheds (outside the Lower Mainland); however, every airshed has a unique mix
of emissions and sources specific to their air quality. In particular, albeit a rigorous
emission inventory has not been generated for the Castlegar airshed, contributions from
airshed sources clearly appear to deviate from the models exhibited in Figures 5 and 6.
For example, road dust and lake bed fugitive dust are major contributors to coarse PM in
Castlegar airshed; however, such sources are not heavily represented in Figure 5.
Although Figures 5 and 6 are general models and are not entirely accurate representations
of relative sources of PM in Castlegar airshed, certain contributors to PM in Castlegar
airshed are consistent with the model. For example, prescribed burning is a significant
contributor to PM in the Castlegar airshed, and such an activity is estimated to comprise
25% of PM10 emissions and 32% of PM2.5 emissions in B.C. airsheds (outside of Lower
Mainland) according to the models in Figures 5 and 6 respectively. In addition,
residential woodstove combustion and pulp mills are included in the PM emissions
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Ministry of Environment
Kootenay Region
ENVIRONMENTAL QUALITY
Ambient Air Quality Monitoring Report
Castlegar, British Columbia
Ambient Air Quality Monitoring Report
Castlegar, British Columbia
models (Figures 5 and 6), and coincidentally, woodstoves and Celgar pulp and paper mill
as well as the Interfor (previously Pope and Talbot) sawmill are significant sources of
PM within Castlegar’s airshed.
4.2 Influences on Air Quality: Weather and Terrain
Aside from both human-caused and naturally occurring emission sources, there are other
factors that play an important role in ambient air conditions. Of primary importance are
the influences of complex terrain (i.e., deep valleys) and weather conditions. Winds in the
airshed generally are aligned with the valley orientation (north-northeast to southsouthwest), which may be the result of either valley channelling or diurnal valley flows
(Figure 7). In either case, the City of Castlegar is more susceptible to PM emissions from
these directions.
Wind speed and direction are important drivers of ambient air pollutant levels. Generally
speaking, low wind speeds, like those often encountered during stagnant winter time
conditions, impede the ability of the atmosphere to disperse pollutants. Of course, wind
direction dictates whether pollutants from any one source are being carried towards or
away from an air quality sampler.
23
Environmental Management Act http://www.env.gov.bc.ca/epd/main/ema.htm.
A Guide to the Open Burning and Smoke Control Regulation
http://www.bclaws.ca/EPLibraries/bclaws_new/document/ID/freeside/34_145_93
24
Model burning bylaw http://www.env.gov.bc.ca/epd/bcairquality/reports/model-bylaw-backyardburning.html
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Ministry of Environment
Kootenay Region
ENVIRONMENTAL QUALITY
The provincial government has implemented a number of programs to reduce the amount
of PM emitted into the atmosphere. Regulations have been passed to reduce smoke from
land-clearing fires and wood stoves 23 . A model bylaw 24 has been developed to assist
municipal governments in designing regulations restricting burning of yard waste on
residential property. In addition, efforts to phase out beehive burners (large domed
incinerators used by lumber mills to burn wood waste) are proceeding, initially focusing
on the most smoke-sensitive areas of the province.
Figure 7. Daily airflow within valleys.
Airflow during the daytime tends to be upslope and up-valley. During the night time this
tendency reverses and denser, cooler air pools in valley bottoms.
Source: The Cooperative Program for Operational Meteorology, Education, and Training (COMET®) Web
site at http://meted.ucar.edu/ of the University Corporation for Atmospheric Research (UCAR), funded by
the National Weather Service. ©2002, UCAR. All Rights Reserved.
The community of
Castlegar frequently
experiences
temperature
inversions because
Castlegar airshed is
surrounded by
steep valley walls.
Valley landforms often experience a phenomenon
known as a temperature inversion. During a
temperature inversion, cold air sinks to and remains
within a valley floor because colder air is denser than
warmer air. Warmer air does not mix with the colder
air because of the density differential, and the colder
air remains trapped within the valley. Temperature
inversions are most prevalent during night (see Figure
7 to see valley flow over a daily period); however,
they also can occur during daytime particularly during
the winter. The community of Castlegar frequently
experiences temperature inversions because Castlegar
airshed is surrounded by steep valley walls.
16
Ministry of Environment
Kootenay Region
ENVIRONMENTAL QUALITY
Ambient Air Quality Monitoring Report
Castlegar, British Columbia
Figure 8. Thermal stratification resulting from temperature inversion.
The warm layer of air on top of the cold layer creates an inversion layer that traps
emissions close to the ground.
Graphic courtesy of Environment Waikato, Government of New Zealand.
There are many flood control and hydroelectric dams located near Castlegar on the
Kootenay and Columbia rivers. The large waterbodies (reservoirs) resulting from such
dams, exert thermal effects 25 on the Castlegar airshed by contributing to cloud masses
which inhibit the “break-up” of the inversions. The resulting effect is a prolonged period
of inversion resulting in poor air quality and increased incidences of adverse health in
residents (especially people with respiratory problems, children, and the elderly) within
the airshed.
Because terrain has such a significant impact on the composition of a body of air, an
airshed often is defined by geographical features. The Castlegar airshed in particular, is
shaped and influenced by the Selkirk Mountain Range and the valley regions surrounding
the confluence of the Kootenay and Columbia rivers. The described landforms
significantly influence the containment and dispersion of air pollutants in Castlegar’s
airshed.
The distance between the surface and the inversion layer is called the “mixing depth”,
and it has a major influence on the dispersion capability of the atmosphere. (The
25
Differences in temperatures and ability to retain heat between land surfaces and water bodies.
17
Ministry of Environment
Kootenay Region
ENVIRONMENTAL QUALITY
Ambient Air Quality Monitoring Report
Castlegar, British Columbia
Ambient Air Quality Monitoring Report
Castlegar, British Columbia
Figure 9. Annual cycle of mixing heights in Castlegar airshed, (elevation 495 m).
The graph displays the variability in monthly vertical movement of air (mixing height)
occurring in Castlegar. Starting from the base (surface) elevation of 495 m (metres above
sea level), the mean mixing height in winter (December and January) is approximately
850 m, (or 355 m above the base) compared to almost 3,200 m (or 2,705 m above base)
in summer (July).
Source: GEM-Scribe VI model output data from Jan 2002 to June 2007, courtesy of Environment Canada,
Pacific Yukon Region. “SE” refers to a statistical term, “standard error”. “SD” refers to a statistical term,
“standard deviation”.
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Ministry of Environment
Kootenay Region
ENVIRONMENTAL QUALITY
analogous term “mixing height” is used for the height above sea level.) The greater the
mixing depth or height, the greater the volume of air in which pollution emitted at the
ground can mix, resulting in lower concentrations. The height of this mixing layer is
driven primarily by hours of sunlight and is therefore seasonal in nature. Figure 9
demonstrates that the long hours of sunlight in summer cause a much greater mixing
height, and the winds are more effective in dispersing pollution. Conversely, in winter,
the small amount of sunlight results in very low mixing heights, so pollution does not get
dispersed, and PM concentrations can rise.
Ambient Air Quality Monitoring Report
Castlegar, British Columbia
5.0 Air Quality in Castlegar
As mentioned above, the PM aspect of air quality is measured in Castlegar via a Partisol
manual sampler. PM10 concentrations have been monitored in Castlegar since 1990.
Table 1 summarizes the results of the PM10 monitoring from the beginning of the
monitoring program to 2007.
The mean and maximum values for each year refer to averages of hourly data over a 24hour period and are measured in micrograms per cubic metre (µg/m3). The percentage of
days with fair, poor, and very poor air quality refer to days when particulate matter
concentrations exceed NAAQO levels. Days with fair air quality have PM10 levels
exceeding Level A (25 µg/m3), poor days exceed Level B (50 µg/m3), and very poor days
exceed Level C (100 µg/m3). The Exposure Indicator is the cumulative value of PM10
amounts that exceed the reference health level of 25 µg/m3 throughout a year (see
Appendix B for the method of calculation). The CWS Indicator adopts the algorithm for
the Canada-Wide Standard for PM2.5 and is calculated by averaging the current year 98th
percentile value with the values of two previous years. CWS Indicators are used for
community cross comparison.
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Ministry of Environment
Kootenay Region
ENVIRONMENTAL QUALITY
Table 3. Summary of annual PM10 in Castlegar from 1990 to 2007.
Ambient Air Quality Monitoring Report
Castlegar, British Columbia
The general trend for PM in Castlegar over the last 18 years (1990 to 2007) appears to be
an overall decrease in ambient PM levels. Statistical testing 26 applied to yearly means
(see Appendix D1) confirms the observed difference between higher PM values in
previous years and lower values in more recent years is significant. In particular,
distinctive differences between means from the first five years of monitoring (1990 to
1994) and means from the last three years of monitoring (2005 to 2007) are apparent.
More specifically, the identified years in the early 1990s appear to have experienced
much higher levels of PM than observed in recent years. In fact, the PM means of every
year in the early 1990s (1990 to 1994) exceed the WHO objective of 20 μg/m3, and all
PM means of the three most recent years of monitoring are below the objective. Data
from the most recent three years of monitoring have produced the lowest mean PM
values observed in the entire monitoring period (see Table 2). This improvement in air
quality may be linked to improvements in emission control technology implemented at
the local pulp mill between 1991 and 1994.
In comparison to other communities, Castlegar appears to experience the mid-range of
PM levels observed throughout B.C. (see Figure 10 for a comparison with selected B.C.
communities). According to statistical testing (see Appendix D2), the Castlegar airshed
mean PM concentrations were below that of Golden but higher than Burnaby. Castlegar
mean PM values displayed no statistical difference from the values of Invermere and
Prince George. MoE uses the terms “clean”, “threatened”, and “degraded” to describe
the air quality within an airshed. The Radium airshed would be classified as “clean”, and
the Golden airshed is considered “degraded”. Castlegar air quality (in terms of PM10) is
classified as “threatened”, but Castlegar airshed does not experience PM levels that
would be considered “degraded”.
Statistical analysis was applied to PM data collected from the communities represented in
Figure 10 for the years of 2003 to 2006 27 . Results from statistical analysis indicate that
not only do significant differences exist between the mean PM values of Castlegar and
certain cities (such as Golden), but a significant differences exist between city and year
for PM, as well. To clarify, a difference in PM values appears to occur from year to year
depending on the city in which PM was measured. For example, Golden experienced
high PM concentrations in 2003 relative to other years in the 2003 to 2006 period
because unusually high forest fire activity occurred in the vicinity of the community. In
contrast, Burnaby data does not display a discrepancy between 2003 and the remainder of
26
Even though calculated averages from data sets superficially may appear to be different in value, the
ranges of the data sets may greatly overlap, and, thus, the PM levels estimated from the data sets would be
far too similar to accept that a distinct difference exists regardless of apparent differences in data averages.
Consequently, statistical tests are employed to determine the likelihood of whether PM levels estimated
from one data set are significantly and distinctly different from levels of another data set.
27
Airshed comparison analysis was conducted solely for the years of 2003 to 2006 because data for all
communities is available only for that period.
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Ministry of Environment
Kootenay Region
ENVIRONMENTAL QUALITY
5.1 Results and Trends
Ambient Air Quality Monitoring Report
Castlegar, British Columbia
the 2003 to 2006 period because the Burnaby airshed was relatively unaffected by the
forest fires near Golden.
50
Burnaby
40
Golden
35
Invermere
30
Prince George
25
Castlegar
20
15
10
5
2006
2005
2004
2003
2002
2001
2000
1999
1998
1997
1996
1995
1994
1993
1992
1991
1990
0
Year
Figure 10. Comparison of particulate matter concentrations between various B.C.
communities.
The above graph displays a comparison of mean annual PM10 concentrations with other
communities in British Columbia from 1990 to 2006.
Figure 11 illustrates that 2007 was a year of relatively low PM concentrations compared
with other years in Castlegar’s full 18-year monitoring period (1990 to 2007). Results
from statistical analysis (see Appendix D5) confirmed that 2007 was a year with
particularly low PM concentrations. In fact, the yearly PM mean for 2007 was lower
than all other calculated yearly PM means derived from 1990 to 2007 data (see Table
2) 28 . This could be associated with changes in production or improvements at the Pope
and Talbot sawmill (now Interfor), and/or the Celgar pulp mill, both of which are
industries within the Castlegar airshed.
28
Such an observation is not statistically significant. 2007 has shown statistically significant differences
with means from 1990, 1991, 1993, and 1994 only.
21
Ministry of Environment
Kootenay Region
ENVIRONMENTAL QUALITY
3
Inhalable Particulate Matter ( μg/m )
45
Ambient Air Quality Monitoring Report
Castlegar, British Columbia
Statistical tests were conducted to compare the monthly means in 2007 with the
combined monthly means of 1990 to 2006 (see Appendix D5). Although PM values in
2007 appear (with statistical significance) to be low relative to other years of the 18-year
monitoring period, the monthly means calculated for both 2007 and 1990 to 2006 data
sets appear to fluctuate from month to month. These monthly fluctuations assume the
same pattern in 2007 data as in 1990 to 2006 data. More specifically, PM values will
fluctuate throughout the year due to changes in environmental conditions that occur with
change in season (i.e., primarily changes in solar heating and winds), and PM fluctuation
patterns essentially remain the same from year to year. Figure 11 illustrates similarities
in seasonal PM changes from year to year.
1990 to 2006
3
2007
25
20
15
10
5
0
Jan Feb Mar Apr May Jun
Jul
Aug Sep Oct Nov Dec
Month
Figure 11. 2007 particulate matter data compared with previous years.
The bars representing the 1990 to 2006 series are derived from mean PM values
calculated for all data collected between 1990 and 2006.
Figure 12 displays NAAQO exposure values derived from Castlegar airshed PM data
over the 18-year monitoring period. Exposure values depict the number of days in a year
PM concentrations exceed the NAAQ Objective of 25 µg/m3. The degree to which PM
concentrations exceed the objective also is incorporated into the exposure concentrations.
Similar to yearly PM concentrations, exposure values have decreased in recent years.
Data from the most recent three years of monitoring indicates a dramatic decrease in PM
exposure has occurred from the early 1990s. Aside from exposure experienced in 1996,
22
Ministry of Environment
Kootenay Region
ENVIRONMENTAL QUALITY
Inhalable Particulate Matter ( μg/m )
30
PM exposure during the last three years
of monitoring were the lowest exposure
PM exposure experienced
values observed in the 18-year
monitoring period. Exposure in 1996
during the last three years
can be considered anomalous because the
of monitoring are of the
value is an unusually greater magnitude
lowest exposure values
lower than the previous (1995) and
succeeding (1997) years by 76% and
observed in the 18-year
79% respectively.
monitoring period.
Although exposure appears to have
increased gradually over the last three
years, this increase should not be cause for concern since 2007 exposure is significantly
less than the exposure mean of all monitored years (1990 to 2007). Thus, 2007 exposure
can be considered as relatively low despite the apparent upward trend occurring over the
last three years of monitoring.
400
NAAQO Exposure
350
300
250
200
150
100
50
2007
2006
2005
2004
2003
2002
2001
2000
1999
1998
1997
1996
1995
1994
1993
1992
1991
1990
0
Year
Figure 12. NAAQO exposure in Castlegar.
The line graph displays the 98th percentiles of PM10 yearly data sets in micrograms
(µg/m3). The bars display NAAQO exposure values depicting excesses of PM10 above
the health objective of 25 µg/m3. Refer to Appendix B for a description on the
calculation of NAAQO exposure.
23
Ministry of Environment
Kootenay Region
ENVIRONMENTAL QUALITY
Ambient Air Quality Monitoring Report
Castlegar, British Columbia
Ambient Air Quality Monitoring Report
Castlegar, British Columbia
Figure 13 provides context for the exposure level displayed in Figure 12, by comparing
PM exposure levels in Castlegar airshed to exposure levels in Golden 29 and Nelson
airsheds. Golden and Nelson are communities also within the Kootenay Mountain
Region having similar populations to Castlegar. However, despite geographical
proximity and similarity in population size, Figure 13 illustrates that Castlegar residents
experience far less exposure to PM10 pollution than Golden. In contrast, Nelson and
Castlegar appear to have relatively similar exposure levels and the community with
higher PM concentrations appears to have alternated several times over the period
indicated in Figure 13 (1992 to 2006).
800
Castlegar
700
Golden
NAAQO Exposure
500
400
300
200
100
2006
2005
2004
2003
2002
2001
2000
1999
1998
1997
1996
1995
1994
1993
1992
0
Year
Figure 13. NAAQO exposure comparison between Castlegar, Golden, and Nelson.
Figure 14 displays the percentages of days within a month that experience PM
concentrations exceeding the NAAQ Objective of 25 μg/m3. Statistically significant
differences exist from month to month between calculated proportions of days in a month
that exceed the objective. The highest proportions of days are observed in the months of
February, March, and August.
February and March, in particular, experience remarkably high levels of PM and are the
only months which PM values exceed 100 μg/m3 (referred to in Figure 14 as “Very Poor
Days”). A possible explanation for the high frequency of days exceeding air quality
objectives in February and March is an increase in the production of fugitive dust
29
As mentioned earlier, Golden airshed is classified as “degraded”.
24
Ministry of Environment
Kootenay Region
ENVIRONMENTAL QUALITY
Nelson
600
Ambient Air Quality Monitoring Report
Castlegar, British Columbia
associated with spring in Castlegar. Castlegar begins to warm in February/March when
snow and ice that covers road surfaces begins to melt. The winter traction material on
roads which is trapped in snow and ice, thaws in early spring releasing sand and gravel.
Vehicular action grinds this material into finer particles and stirs it up, increasing the
amount of fugitive dust in the atmosphere. The resulting fugitive dust dramatically
increases the PM10 concentrations within ambient air; therefore, Castlegar experiences a
high number of fair, poor, and very poor days during February and March (see Figure
14).
50%
Fair Days
Precentage of Days in Month
45%
Poor Days
40%
Very Poor
Days
35%
30%
25%
20%
15%
10%
5%
0%
Jan
Feb
Mar
Apr
May
Jun Jul
Month
Aug Sep
Oct
Nov Dec
Figure 14. Percentages of days in a month with values exceeding NAAQ objective.
The above graph displays the percentage of days that exceed NAAQO levels in
Castlegar during the period of 1990 to 2007 (n=262). The percentage of very poor (100
µg/m3), poor (50 µg/m3), and fair days (25 µg/m3) measured in each month are shown by
the bars.
Figure 16 displays the monthly PM data averaged over the 18-year monitoring period.
After conducting statistical tests (see Appendix D3), significant differences between
monthly data only appear to be associated with February, March, and August. In
25
Ministry of Environment
Kootenay Region
ENVIRONMENTAL QUALITY
August also experiences a high proportion of days exceeding air quality objectives. The
probable explanation for increased PM in August is forest fires. Much of the wildfire
activity in the Kootenays occurs during August; therefore, an elevated amount of PM is
emitted into the atmosphere during the month.
Ambient Air Quality Monitoring Report
Castlegar, British Columbia
particular, February and March are significantly greater than every month of the year 30
(except August and November 31 ). In addition, August values are greater (according to
statistical testing) than June, September, and December; however, no significant
difference is apparent between the high PM values observed in February and March 32 .
Results from analyzing monthly data are coincident with the percentages of days
exceeding air quality objectives levels (see Figure 14): February and March exhibiting
the highest proportions of fair/poor/very poor air quality days and August exhibiting high
(but not highest) proportions of fair/poor days.
25
20
15
10
5
0
Jan
Feb
Mar
Apr
May
Jun
Jul
Month
Aug
Sep
Oct
Nov
Dec
Figure 15. PM10 in Castlegar airshed by month.
The bars represent monthly means of daily PM10 concentrations collected during the
period of 1990 to 2007.
Statistical tests were applied to PM data categorized by day of week and averaged over
the 18-year monitoring period (see Appendix D4), and a distinctive difference in PM
levels appears to occur between Friday and Sunday. The difference between the days is
much higher concentrations of PM appear to occur on Fridays than Sundays (see Figure
16). The explanation for such a discrepancy could relate to a combination of commuter
and tourist traffic. Because Friday is a weekday (i.e., a common workday), heavy
30
However, February PM levels do not appear to be different from July’s but March PM levels are
statistically greater than those of July.
31
November appears to be mid to high range in PM values. November PM ranges overlap with every
month (even the high PM months of March and February) except June. However, the statistical evidence
suggest November PM levels is different (higher) than June’s is weak.
32
Such an observation suggests that August may not be the highest month for PM; however, August PM
levels are high enough that their ranges significantly overlap with ranges observed in February and March.
26
Ministry of Environment
Kootenay Region
ENVIRONMENTAL QUALITY
Inhalable Particulate Matter ( μ g/m3)
30
Ambient Air Quality Monitoring Report
Castlegar, British Columbia
Another noted difference in daily PM levels appears to occur between PM values of
Fridays and those of Monday. The difference is possibly a result of incorporating PM
values collected on public holidays (i.e., long weekends) into the Monday mean. Low
commuter traffic occurs on public holidays; therefore, a PM mean which represents the
entirety of Mondays within a year would be expected to be slightly less than the mean of
other weekdays 33 .
A less significant difference in PM levels is observed to occur between Thursdays and
Sundays in the manner that Thursday PM levels appear to be slight higher than Sunday
levels. The difference is likely a result of incorporating PM values collected on
weekends where tourists may have taken a vacation day on Friday to extend a weekend
trip. In such cases, Thursday could be a travelling day and therefore be associated with
both commuter and tourist traffic. Consequently, PM values appear be slightly elevated
on Thursdays. However, since Friday is typically a standard work day, the difference
between Thursday PM and the weekend is supported only weakly by statistical evidence.
33
Statistical differences associated with Monday data only are observed as a difference between Monday
and Friday PM values.
27
Ministry of Environment
Kootenay Region
ENVIRONMENTAL QUALITY
commuter traffic commonly is associated with the day. However, in addition to
commuters, traffic resulting from tourism increases on Fridays because many people
travel to their tourist destination on Fridays to arrive by the weekend. In contrast,
Sundays may have high tourist traffic (because people are returning from their tourist
destination); however, the day is associated very little commuter traffic. Furthermore,
many businesses are closed on Sundays; therefore, vehicular traffic is further diminished
because Castlegar residents generally perform weekend errands and shopping on
Saturdays. In summary, Friday PM values are generally high due to a combination of
heavy commuter and tourist traffic, and Sunday PM values are often low because of low
commuter traffic and decreased amount of open businesses in Castlegar.
25
20
15
10
5
0
Monday
Tuesday
Wednesday
Thursday
Friday
Saturday
Sunday
Day of Week
Figure 16. PM10 in Castlegar airshed by day of week.
The bars represent PM10 concentration data collected over the duration of 1990 to 2007
and averaged for each day of the week.
28
Ministry of Environment
Kootenay Region
ENVIRONMENTAL QUALITY
Inhalable Particulate Matter ( μ g/m3 )
Ambient Air Quality Monitoring Report
Castlegar, British Columbia
Ambient Air Quality Monitoring Report
Castlegar, British Columbia
6.0 Conclusions and Recommendations
In summary:
¾ Air quality has undergone dramatic improvement since the early 1990s. This is
partially due to improvements between 1991 and 1994, in emission control
technology at the pulp mill located within the Castlegar airshed.
¾ Every year, several days exist when PM levels exceed national guidelines for
acceptable air quality, putting the air quality in Castlegar in the “threatened”
category. Such days are of concern to public health officials.
¾ Days with PM concentrations that exceed standards often are observed in
February, March, and August. The high levels of PM in the aforementioned
months result from a combination of natural and human causes.
¾ The steep valley walls surrounding Castlegar increases the airshed’s susceptibility
to temperature inversions (especially during winter) trapping PM near ground
level. Inversions during periods of higher emissions from sources such as road
dust and wood burning appliances may result in increased incidences of adverse
health effects to residents within Castlegar airshed.
¾ Differentiating between sources and types of PM within Castlegar airshed is
difficult because only discrete PM10 data is available. A more comprehensive PM
monitoring program incorporating continuous PM2.5 and PM10 measurements, is
needed to inform airshed management decisions.
¾ Based on data from the full 18-year monitoring period, Castlegar airshed appears
to fall within the mid-range in terms of ambient air concentrations of PM within
various airsheds throughout B.C. However, PM levels have been particularly low
during the most recent three years of monitoring, and continued air quality
monitoring will provide insight on whether Castlegar is becoming a community
with “cleaner” air than most others in B.C
¾ Since there is a high potential for inversions in Castlegar, the community should
be concerned about ambient PM levels. Even low or moderate levels of PM
emissions can be magnified by the effects of inversions, resulting in negative
health effects. Furthermore, the community should be attempting to reduce levels
29
Ministry of Environment
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ENVIRONMENTAL QUALITY
¾ In particular, 2007 may have experienced the lowest mean PM concentration
observed in 18 years.
Ambient Air Quality Monitoring Report
Castlegar, British Columbia
of PM since there is no minimum health impact level or ‘safe’ level of PM10 or
PM2.5 34 .
The following are some recommendations to improve current air quality in Castlegar:
¾ Residents who wish to use wood as fuel source should be encouraged to buy more
efficient wood heat appliances (woodstoves).
¾ Local municipalities should continue to identify different/additional techniques
that could result in more efficient winter road maintenance and reduction of road
dust. Examples of such measures are more frequent street cleaning, coarser sand
for roadways, and possibly the use of magnesium chloride to keep roadways clear
of ice. A recent collaboration between MoE and the Ministry of Transportation
and Highways has resulted in the development of a ‘best management practises’
document. This can be found at:
http://www.env.gov.bc.ca/epd/bcairquality/reports/topic_Dust.html
¾ Local municipalities are encouraged to engage in air quality management
planning. A tool to assess the need for planning and the options to consider has
been developed and can be accessed at:
http://www.cleanairbc.com/
Additional information on air quality management planning can be found at:
airshedplan_provframework.pdf
¾ Bylaw enactment and enforcement is another tool often used to improve local air
quality.
The following sites offer examples to help guide local levels of
government in bylaw development:
Backyard burning bylaw template:
http://www.env.gov.bc.ca/air/particulates/pdfs/bylaw.pdf
34
http://www.healthservices.gov.bc.ca/pho/pdf/phoannual2003.pdf
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Ministry of Environment
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¾ Residents should be educated in techniques of efficient woodstove operation,
selection of fuel, and proper storage and curing of wood.
Ambient Air Quality Monitoring Report
Castlegar, British Columbia
For More Information
The Environmental Quality Branch of the Ministry of Environment has several reports on
air quality at http://www.bcairquality.ca/reports/topic_Monitoring.html
A report on Air Quality in the Kootenays 1993-1999 is available at
http://www.env.gov.bc.ca/epd/regions/kootenay/aq_reports/pdf/kootenay_air_quality_rep
ort.pdf
B.C. provincial legislation related to air quality is described at
http://www.env.gov.bc.ca/epd/bcairquality/regulatory/air-regulations.html
The 2003 Provincial Health Officer annual report about air quality in British Columbia
can be found at http://www.env.gov.bc.ca/epd/bcairquality/reports/phoannual2003.html
Ministry of Environment
Contact: Paul Willis
205 Industrial Rd. G,
Cranbrook, B.C. V1C 6H3
Phone: (250) 489-8540
Fax: (250) 489-8506
Email: [email protected]
Public feedback is welcomed
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Ministry of Environment
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ENVIRONMENTAL QUALITY
The Environmental Protection Division of the Ministry of Environment in the Kootenay
Region has information at http://www.env.gov.bc.ca/epd/regions/kootenay/index.htm
Ambient Air Quality Monitoring Report
Castlegar, British Columbia
Appendices
98th percentile
In a sequential list of data values, the 98th percentile is the
data value that is 98 percent of the way through the list from
the smallest reading (or 2 percent below the highest reading).
The absolute maximum reading is not used for analysis
because an unusually high reading may be the result of
outlier (or suspect) data and can distort the analysis unduly.
Aerosol
A particle of solid or liquid matter that can remain suspended
in the air because of its small size (generally under one
micron).
Air pollution
Degradation of air quality resulting from unwanted chemicals
or other materials occurring in the air.
Airshed
A geographic area that, because of topography, meteorology,
and/or climate, is frequently affected by the same air mass. In
general, it is that body of air in which management strategies
of any individual emission source can have a discernible
effect.
Air Quality Index (AQI) Reports levels of ozone, particulate matter, and other
common air pollutants. Higher AQI ratings for a pollutant
indicate higher levels of contaminants in an airshed. For
guidance on how to compute the AQI, see
http://a100.gov.bc.ca/pub/aqiis/air.info.
Anthropogenic
Produced by human activities.
ARB
Air Resources Branch, Ministry of Environment
Area source
An emission source of pollutants that covers a large, and
sometimes poorly defined, area – sometimes call non-point
source (e.g., prescribed burning and residential fuel wood
combustion). Note: A single residential wood burning
appliance is considered a small source of emissions, but
many appliances together can emit a significant amount of
emissions, and are collectively thought of as an area source,
instead of many small point sources.
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Appendix A - Glossary and Abbreviations
Biogenic
Having to do with living organisms as sources. For example,
major sources of biogenic emissions in the Kootenay Region
are trees.
Carbon monoxide (CO)
A colourless, odourless, poisonous gas, produced by
incomplete burning of carbon-based fuels.
Central tendency
In statistics, a measure of the middle or center of a set of
data. The arithmetic mean is the most commonly used, but
median, mode, and geometric mean are also used.
CEPA/FPAC
The Canadian Environmental Protection Act FederalProvincial Advisory Committee directs the development and
assessment of National Ambient Air Quality Objectives
(NAAQOs) for airborne pollutants.
Coarse fraction
Particulate matter with diameter between 2.5 and 10 microns
(PM10-2.5). Also referred to as “inhalable particulate matter.”
CWS Indicator
A measure of the severity of maximum levels of PM2.5
concentration. The 98th percentile of the daily means is
determined for each year, then averaged for the last three
calendar years (which reduced the influence of a particularly
bad year). This value can then be compared to a given
standard and to other communities. Though the CWS
standard for particulate matter is limited to
PM2.5
concentrations, this report adopts this algorithm for PM10
analysis and comparison purposes.
Emissions Inventory (EI) A list of air pollutants emitted into a community's
atmosphere in amounts (commonly tonnes) per day or year,
by type of source.
Exposure Indicator
A measure of the accumulated exposure to PM10 over a
specified time (typically one year), taking into account both
the concentration of PM10 and the length of time of exposure.
Larger exposures indicate an increased risk to human health.
Fine fraction
Particulate matter with diameter less than 2.5 microns; PM2.5.
Also referred to as “respirable particulate matter”.
Fugitive dust
PM10 from finely ground rock and clay, origination from
human sources such as sand and gravel traction material
applied to roads in winter, or from natural sources such as
exposed lake beds and river banks.
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Ambient Air Quality Monitoring Report
Castlegar, British Columbia
Haze
Atmospheric aerosol of sufficient concentration to be visible.
The particles are so small that they cannot be seen
individually but are still effective at attenuating light and
reducing visual range.
Inversion
An increase in temperature with height, which is the reverse
of the normal cooling with height in the atmosphere. Warm
air at ground level tends to rise, but because warmer air is
already above it, vertical air movement is minimized,
trapping atmospheric pollutants in the lower troposphere, and
resulting in higher concentrations of pollutants at ground
levels than would usually be experienced.
Mean
In statistics, an “average” (arithmetic mean) calculated by
dividing the total of all values of a set of data by the number
of values. (In special circumstances, the geometric mean is
used instead)
Median
In statistics, the value closest to the middle in a ordered list of
data values.
MoE
B.C. Ministry of Environment. (formerly Ministry of Water,
Land, and Air Protection - MWLAP).
MELP
B.C. Ministry of Environment, Lands and Parks. (predecessor
to MWLAP).
μg/m3
Micrograms per cubic metre (concentration)
μm
Micrometres (10-6 m) (diameter)
Mobile sources
Motor vehicles and other moving objects that release
pollution; mobile sources include cars, trucks, buses, planes,
trains, motorcycles, and gasoline-powered lawn mowers.
Mobile sources are divided into two groups: road vehicles,
which include cars, trucks, and buses, and non-road vehicles,
which includes trains, planes, and lawn mowers.
MWLAP
B.C. Ministry of Water, Land and Air Protection (formerly
Ministry of Environment, Lands and Parks and now the
Ministry of Environment).
NAPS
National Air Pollution Surveillance Network. NAPS was
established by Environment Canada to monitor and assess the
air quality in Canadian urban regions.
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Ambient Air Quality Monitoring Report
Castlegar, British Columbia
NAAQO
National Ambient Air Quality Objectives. Health-based
pollutant
concentration
objectives,
developed
by
Environment Canada and used as objectives and standards in
B.C.
NAAQS
National Ambient Air Quality Standards. Health-based
pollutant concentration limits established by the United
States Environmental Protection Agency that apply to outside
air.
Nitrates (NO3-)
The gases and aerosols that have origins in the gas-to-aerosol
conversion of nitrogen oxides, e.g., NO2; of primary interest
are nitric acid and ammonium nitrate.
Nitrogen oxides (NOx)
Gases formed mainly from atmospheric nitrogen and oxygen
when combustion takes place under conditions of high
temperature and high pressure; considered a major air
pollutant and precursor of ozone.
NOx
NO + NO2 + poorly defined fraction of other NOx species
(given conventional analyzers).
Ozone (O3)
A major component of smog. Ozone is not emitted directly
into the air but is formed by the reaction of volatile organic
compounds (VOCs) and NOx in the presence of heat and
sunlight.
Particulate matter (PM) A generic term referring to liquid or solid particles suspended
in the air.
PM2.5
Particulate matter less than 2.5 microns in diameter: the fine
fraction of PM, also called respirable particulate matter. Tiny
solid or liquid particles, generally soot and aerosols. The size
of the particles (2.5 microns or smaller, about 0.0001 inches
or less) allows them to easily enter the air sacs deep in the
lungs where they may cause adverse health effects. PM2.5 also
causes visibility reduction.
PM10
Particulate matter less than 10 microns in diameter, including
both coarse and fine fractions, also called inhalable
particulate matter. Tiny solid or liquid particles of soot, dust,
smoke, fumes, and aerosols. The size of the particles (10
microns or smaller, about 0.0004 inches or less) allows them
to easily enter the respiratory system where they may be
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Ambient Air Quality Monitoring Report
Castlegar, British Columbia
Ambient Air Quality Monitoring Report
Castlegar, British Columbia
PM10-2.5/PMcoarse
Particulate matter between 2.5 and 10 microns in diameter;
the coarse fraction of PM. Particles that are typically
generated by mechanical grinding or crushing (e.g. road dust)
but can include soot, ash and pollen (biogenic) particles.
These particles are less likely to enter the air sacs of the lungs
but instead are trapped by the mucous membranes and other
lung defenses. Coarse particles are not deemed as dangerous
to human health as PM2.5 but are, nevertheless, associated
with inflammatory symptoms such as asthma and other
respiratory ailments.
Point source
An emission source of pollutants that remains in a small
identifiable area (e.g., an industrial plant)
Primary particle
The fraction of PM2.5 or PM10 that is directly emitted from
combustion and fugitive dust sources.
Primary pollutant
The emissions discharged from a source that either retain
their form or are transformed into secondary pollutants.
Secondary particle
The fraction of PM10 and PM2.5 that is formed in the
atmosphere. Secondary particles are products of the chemical
reactions between primary pollutant gases, such as nitrates,
sulphur oxides, ammonia, and organic products.
SO2
See Sulphur dioxide
Sulphur dioxide (SO2)
A pungent, colourless gas formed as a byproduct of the
combustion of fossil fuels.
TEOM
Tapered element oscillating microbalance. An instrument for
the continuous measurement of PM.
Ultrafine fraction
Particulate matter with diameter less than 0.1 microns.
WHO
World Health Organization. The World Health Organization
has identified objectives for yearly PM means and
recommends means (calculated by averaging daily PM values
over a year) should remain below objective levels. The
objective for PM10 is 20 μg/m3, and the objective for PM2.5 is
10 μg/m3.
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Ministry of Environment
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ENVIRONMENTAL QUALITY
deposited, resulting in adverse health effects. PM10 also
causes visibility reduction and is a criteria air pollutant.
Ambient Air Quality Monitoring Report
Castlegar, British Columbia
Appendix B – NAAQO Exposure Calculations
Exposure calculations are based on the assumption that there is a concentration (25
μg/m3) below which there is minimal risk to health, and above which there exists a
statistically significant greater health response. This reference level can be exceeded
either by a short period of exposure to high concentrations, or a longer period of exposure
to lower concentrations.
Although there are many different ways to calculate exposure, the values cited in this
report were calculated based on the NAAQO definition. This method assumes that PM10
has negligible health effects until the daily mean exceeds a reference health level of 25
µg/m3. For days in which this threshold is exceeded, the difference between the daily
mean and the reference level is computed, divided by 10, and rounded up to the nearest
whole number. After this is done for each day in a particular year, the numbers are
summed to provide an overall measure of exposure. An objective level of NAAQO
exposure has not been identified; however, exposure values may be used in both interannual and inter-site comparisons.
Because the monitoring in Castlegar is done on a non-continuous basis, many days, for
many years, did not have a daily mean for PM10. Thus, exposure values were
extrapolated from the days for which daily means were available.
For example, suppose that for a given year, 58 daily means were available and the
NAAQO exposure calculation is applied to this 58 day dataset, with a resultant value of
85. An estimate for the year can then be achieved by assuming that the days sampled are
representative of PM levels over the entire year and scaling the level of exposure
accordingly. Thus, for our example, since the year had 365 days, we can multiply
85*(365/58) = 534.9 to get an estimate of the NAAQO exposure for this year.
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Ministry of Environment
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An exposure calculation is a technique to combine the AMOUNT of a pollutant to which
we are exposed, and the TIME that we are exposed to the pollutant. At the two extremes,
a low concentration of a pollutant could be in the air for several months, yielding an
exposure, but the same exposure would result if there was a high concentration of the
pollutant for a few days and clean air for the rest of the time. (One of the assumptions is
that these two types of exposures will have similar effects on human health.)
Ambient Air Quality Monitoring Report
Castlegar, British Columbia
Appendix C – Central Tendency and Statistical Significance 35
The arithmetic mean is the most commonly used measure of central tendency (see Table
2 and Figure 10). The mean accounts for every value in a population and, thus, is the
most effective measure of central tendency in a normally distributed 36 population.
However, the mean is not appropriate for highly skewed distributions 37 and is less
effective than other measures of central tendency when extreme values are prevalent.
Environmental data often is highly skewed and arithmetic means tend to be unduly
influenced by extreme events; thus, such measures are not representative “typical” or
“central” tendencies. Instead, obtaining geometric mean or log transforming could be
viable alternatives for determining central tendency provided values are positive and
distribution is positively skewed. Castlegar PM10 data appears to be a typical example of
environmental time series data because data distribution is skewed (see Figure A1).
Figure A1. Histogram of Castlegar PM10 data distribution
35
Although this report explains the concepts of statistics needed to understand Castlegar’s air quality, other
reference material should be consulted to understand all the details of the report. Some statistical results
have been included for those conversant with advanced statistical concepts.
36
The normal distribution (the “bell-shaped curve” which is symmetrical about the mean) is a theoretical
function commonly used in inferential statistics as an approximation to sampling distributions. Normal
distributions are symmetric with scores more concentrated in the middle than in the tails.
37
A distribution is skewed if one of its tails is longer than the other. A positive skew means that it has a
long tail in the positive direction (sometimes called “skewed to the right”) and a negative skew has a long
tail in the negative direction (sometimes called “skewed to the left”).
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Ministry of Environment
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In statistics, central tendency is a measure of the location of the middle or the centre of a
distribution of data. The definition of “middle” or “centre” purposely is left somewhat
vague to enable the term “central tendency” to refer to a wide variety of measures.
Ambient Air Quality Monitoring Report
Castlegar, British Columbia
A common statistical approach to find the best central tendency measure is to
transform the data in some manner so they approximate a normal distribution. In
the case of the Castlegar data, the natural logarithm of the original data results in
a more normally distributed curve (see Figure A2).
200
180
160
140
100
80
60
40
20
0
0
1
2
3
4
5
6
LN [Particulate Matter (μ g/m3)
Figure A2. Histogram of the natural logarithm of Castlegar PM10 data
Central tendency is extrapolated from the transformed data. Calculation method consists
of obtaining yearly averages from transformed data. Confidence intervals at the 95%
level 38 are calculated for estimated means. 39
Figure A3 displays means of log transformed data with the confidence intervals (range in
blue vertical lines) for each year. An overall mean for all years is calculated by obtaining
the (arithmetic) mean from the yearly means when values are in logarithmic form. The
total mean and corresponding confidence intervals are demarcated in Figure A3 with a
black horizontal line and dashed horizontal lines, respectively. One should note that
means based on log transformed data do not provide specific information on the actual
concentrations of PM in Castlegar. Rather, log transformed data serves to expose which
years deviate from the norm (overall average).
38
In other words, the mean is considered statistically significant within these upper and lower limits with
95% confidence, or nineteen times out of twenty. Means outside of this range cannot be considered similar
and represent statistical departures from typical values.
39
A test for autocorrelation (estimated to be less than .2) suggests that there is little autocorrelation; hence,
the ambient levels between years can be considered independent of each other.
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Ministry of Environment
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Count
120
Ambient Air Quality Monitoring Report
Castlegar, British Columbia
3.50
3.00
2.50
2007
2006
2005
2004
2003
2002
2001
2000
1999
1998
1997
1996
1995
1994
1993
1992
1991
1990
2.00
Year
Figure A3. Annual variation of the mean and range of PM10 in Castlegar.
The above figure depicts the statistical significance of yearly levels of PM10. The red
circles represent the annual geometric mean of PM10 data, and show that several years
were significantly different than the overall mean of all data.
Figure A3 is a particularly useful graph for determining which yearly sets of data
significantly deviate from the total average data range. In specific reference to Castlegar,
deviations are observed with the years 1991, 1993, 1994, 2005, 2006, and 2007. A year’s
data is considered to deviate from the overall average when the 95% confidence interval
pertaining to the year is outside of the 95% confidence interval constructed for the overall
mean. Yearly data from 1991, 1993 and 1994 appear to exceed the concentration range,
and data from 2005, 2006, and 2007 fall below the concentration range. Investigation
into the possible reasons certain deviate from the average data range is beyond the scope
of this report; however, parties involved with airshed management planning may wish to
conduct such investigations before executing management plans.
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Ministry of Environment
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LN[Particulate Matter (mg/m3)]
4.00
Ambient Air Quality Monitoring Report
Castlegar, British Columbia
Appendix D – ANOVA Tests
A two-way ANOVA was employed on data organized by two categorical designations.
For example, in the air quality comparison between Castlegar and various other B.C.
communities, variables were defined by both the city and the year in which data was
collected. A two-way ANOVA conducts comparison analyses for both category
designations and determines whether the categories interact with one another. Category
interaction essentially describes whether a difference between variables would be
observed depending on both variables rather than just one. In the city comparison
example, interaction effects determine whether yearly variables are different from one
another depending on the city in which the data was collected.
ANOVA analysis examines overall differences between variables; however, specific
differences between variables are not accounted for in the analysis. In order to determine
whether specific variables differ from one another (i.e., is March data different from June
data?) post hoc analysis is required. For the one-way ANOVA tests, Tukey’s post hoc
analysis was employed, and, for two-way ANOVA, hypothesis testing was applied.
An assumption made before applying a parametric statistical process such as ANOVA to
the data is that the data normally distributed. Such an assumption is violated by the
heavy right tail skew associated with the data distribution (see Figure A1); therefore, a
natural logarithmic transform is applied to data before conducting ANOVA to ensure data
conforms (roughly) to a normal distribution. See Appendix C for clarification.
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ANOVA tests were applied to data in which multiple comparisons were made. For
example, comparison analysis involving monthly data require more that one comparison
because twelve data sets (one for each month) are included in the analysis. Therefore, the
analysis takes the form: January compared with February, January compared with March,
March compared with April, etc. ANOVA tests allow for all possible comparison to be
made, and the output of the tests provides insight on whether authentic differences
between variables (such as months in the described example) exist.
Ambient Air Quality Monitoring Report
Castlegar, British Columbia
Appendix D1 – ANOVA Applied to Yearly Data
Sum-of-Squares
26.465
262.839
df
17
1078
Mean-Square
1.557
0.244
F-ratio
6.385
P
0
Tukey’s Post Hoc
ENVIRONMENTAL QUALITY
Source
Year
Error
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Ministry of Environment
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Ambient Air Quality Monitoring Report
Castlegar, British Columbia
Appendix D2 – Two-Way ANOVA Applied to City Comparisons
Source
City
Year
Interaction
Error
Sum-of-Squares
37.611
0.656
10.427
550.059
df
4
3
12
1552
Mean-Square
9.403
0.219
0.869
0.354
F-ratio
26.53
0.617
2.452
P
0
0.604
0.004
Castlegar
And
Burnaby
Source
Hypothesis
Error
SS
15.952
550.059
df
1
1552
MS
15.952
0.354
F
45.008
P
0
Castlegar
And
Golden
Source
Hypothesis
Error
SS
1.135
550.059
df
1
1552
MS
1.135
0.354
F
3.202
P
0.074
Castlegar
And
Invermere
Source
Hypothesis
Error
SS
0.014
550.059
df
1
1552
MS
0.014
0.354
F
0.039
P
0.844
Castlegar
And
Prince George
Source
Hypothesis
Error
SS
0.091
550.059
df
1
1552
MS
0.091
0.354
F
0.257
P
0.612
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Hypothesis Testing
Ambient Air Quality Monitoring Report
Castlegar, British Columbia
Appendix D3 – ANOVA Applied to Monthly Data
.
Source
Sum-of-Squares
Df
Mean-Square
F-ratio
P
Month
Error
18.706
270.598
11
1084
1.701
0.25
6.812
0
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
Jan
1
0.01
0
1
1
0.99
1
0.45
1
1
0.77
1
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
1
1
0.02
0
0
0.22
0.97
0
0.06
0.83
0
1
0
0
0
0.03
0.63
0
0.01
0.34
0
1
1
0.99
1
0.48
1
1
0.79
1
1
1
0.95
0.16
1
1
0.41
1
1
0.59
0.02
1
0.88
0.09
1
1
0.97
0.71
1
1
0.84
1
0.04
0.79
1
0.07
1
0.94
0.15
1
1
0.96
0.98
1
0.23
1
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Tukey’s Post Hoc
Ambient Air Quality Monitoring Report
Castlegar, British Columbia
Appendix D4 – ANOVA Applied to Day of Week Data
Source
Day of Week
Error
Sum-of-Squares
4.956
284.348
df
6
1089
Mean-Square
0.826
0.261
F-ratio
3.164
P
0.004
Monday
Tuesday
Wednesday
Thursday
Friday
Saturday
Sunday
Monday
1
0.939
0.966
0.599
0.047
0.968
0.95
Tuesday
Wednesday
Thursday
Friday
Saturday
Sunday
1
1
0.994
0.47
1
0.364
1
0.986
0.392
1
0.44
1
0.874
0.986
0.087
1
0.389
0.001
1
0.447
1
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Tukey’s Post Hoc
Ambient Air Quality Monitoring Report
Castlegar, British Columbia
Appendix D5 – Two-Way ANOVA Applied to 2007 Comparison
with 1990 to 2006.
.
Sum-of-Squares
df
Mean-Square
F-ratio
P
Year Group
6.022
1
6.022
24.708
0
Month
6.578
11
0.598
2.454
0.005
Interaction
Error
3.194
261.265
11
1072
0.29
0.244
1.191
0.288
ENVIRONMENTAL QUALITY
Source
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Castlegar, British Columbia
Appendix E – G-Test Statistics
G-tests were used to analyse monthly differences in proportion of days that exceed the
NAAQO air quality target of 25 μg/m3. Basically, the test examines whether days that
exceed the target are in relatively the same proportions (from month to month) with days
that do not exceed the target.
Value
G
df
P
Minimum Expected
59.3
11
p<0.001
20.1
Month
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
Total
Does Not Exceed Objective
23
(22.5)
32
(20.1)
44
(22.7)
17
(21.5)
10
(22.0)
14
(21.5)
17
(22.0)
32
(22.5)
17
(21.5)
15
(22.0)
24
(21.5)
17
(22.2)
262
Exceeds
Objective
71
(71.5)
52
(63.9)
51
(72.3)
73
(68.5)
82
(70.0)
76
(68.5)
75
(70.0)
62
(71.5)
73
(68.5)
77
(70.0)
66
(68.5)
76
(70.8)
834
Total
94
84
95
90
92
90
92
94
90
92
90
93
1096
Values in parenthesis are expected values.
47
Ministry of Environment
Kootenay Region
ENVIRONMENTAL QUALITY
Contingency Table
Ambient Air Quality Monitoring Report
Castlegar, British Columbia
Appendix F – Yearly PM Comparisons to Objective
Figure A4. Yearly PM10 values compared to air quality objective.
The above figure displays yearly average values for PM10 concentrations. Error bars
represent 95% confidence intervals. The line representing the air quality objective is
aligned with the 20 μg/m3 mark upon the y-axis.
48
Ministry of Environment
Kootenay Region
ENVIRONMENTAL QUALITY
The current report frequently refers to the air quality objective of 20 μg/m3. Figure A4
displays how the yearly means of PM10 compare to the objective. The error bars in
Figure A4 depict 95% confidence intervals, and PM10 concentrations are assumed to fall
within the range of a year’s interval during 95% of the year. Therefore, if a confidence
interval overlaps the objective, 20 μg/m3 may be considered a relatively regular (i.e.,
within 95% range of PM10 concentrations) concentration for a day within the year to
which the interval pertains.
Ambient Air Quality Monitoring Report
Castlegar, British Columbia
Table A1. Results from z-test analysis applied to yearly data.
The above table summarizes the results from statistical comparisons between the air
quality objective of 20 μg/m3 ambient air concentration of PM10. The “Difference”
column indicates whether a yearly PM10 average is lower, higher, or similar (i.e., not
different) than the objective level according to statistical output. The “Statistical
Evidence” column displays the degree to which statistical output supports a claim that a
yearly average is different from the objective.
49
Ministry of Environment
Kootenay Region
ENVIRONMENTAL QUALITY
Z-tests were employed to determine how yearly PM10 means deviate from the objective
of 20 μg/m3 (see Table 2). No yearly means appear to exceed the objective with
statistical significance. Analysis of the first five years of monitoring (1990 to 1994)
indicates the mean yearly PM10 values of the early 1990s were significantly higher than
the air quality objective. In the more recent years of 2005, 2006, and 2007 PM levels
appear to fall below the air quality objective.
Ambient Air Quality Monitoring Report
Castlegar, British Columbia
Appendix G1 – Particulate Matter Air Quality Sampling in
Castlegar
Start – End Date
Parameter
Sampling Type and Frequency
MoE Site Identification
Mar 1985 – Feb 1987
TSP
Discrete Manual, 1-in-6 days
Mar 1987 – Sep 1991
TSP
Discrete Manual, 1-in-6 days
Apr 1990 – Sep 2002
PM10
Discrete Manual, 1-in-6 days
Apr 2001 – present
PM10
Discrete Manual, 1-in-6 days
Centennial Library
0250003
Senior Citizen Centre
E206931
Senior Citizen Centre
E206931
Fire Hall
E243617
50
Ministry of Environment
Kootenay Region
ENVIRONMENTAL QUALITY
Table A2. Dates and types of the PM monitoring programs in Castlegar.
PM10 refers to coarse particulate matter. TSP refers to “Total Suspended Particulate”.
Ambient Air Quality Monitoring Report
Castlegar, British Columbia
Some communities have had samplers located in several sites within their boundaries. If
there was more than one site, the quantity is listed in parentheses after the community
name. The Dates of Operation list the first and last dates of any sampling for each
airshed, but are not specific for each parameter. The Parameters Measured lists all
parameters that have been measured at each site. Not all parameters have been measured
at all times. Golden underwent a Source Apportionment Study, hence had some
specialized sampling equipment.
Legend
Total suspended
TSP
NO2
Nitrogen dioxide
particulates
PM10
Particulate matter (up
to 10 μm diameter)
NO
Nitric oxide
PM2.5
Particulate matter (up
to 2.5 μm diameter)
SO2
Sulphur dioxide
PM Coarse
PM10-2.5
CO
Dustfall
Dustfall
Metals
TRS
O3
Heavy metals: arsenic,
cadmium, zinc
Total reduced sulphur
Ozone
Carbon monoxide
An instrument for measuring
Aethalometer
elemental (black) carbon
PM
Instruments that measure specific
speciation
chemicals found in emissions
VOC
Volatile organic compounds
Met
Meteorological (weather) data
Table A3. Dates and parameters measured at Kootenay Region air quality
monitoring sites.
Airshed
Canal Flats
Castlegar (9
sites)
Dates of Operation
February 1974 – January 1985
March 1985 - present
51
Parameters
Measured
Dustfall
TSP
PM10
Dustfall
Metals
TRS
NO2
SO2
CO
Met
Ministry of Environment
Kootenay Region
ENVIRONMENTAL QUALITY
Appendix G2 – Air Quality Sampling Sites and Parameters in
Kootenay Region Communities
Ambient Air Quality Monitoring Report
Castlegar, British Columbia
Cranbrook
Creston
Dates of Operation
Apr 1985 – Mar 1991
May 1990 – Sep 1993
Apr 1994 – Nov 1998
Mar 2001 – Sep 2006
September 1990 – present
Elk Valley (4
sites)
April 1978 – present
Elkford
October 1982 – March 1993
Golden (4 sites)
January 1992 – present
Grand Forks
August 1973 – present
Invermere
Kimberley
July 1993 - present
May 1988 – present
52
Parameters
Measured
TSP
PM10
Met
PM10
PM2.5
CO
NO2
O3
SO2
Met
TSP
PM10
PM2.5
Dustfall
TSP
PM10
Dustfall
PM10
PM2.5
PM coarse
Aethalometer
PM speciation
VOC
NO2
NO
CO
O3
SO2
Met
TSP
PM10
PM2.5
Dustfall
Met
PM10
TSP
PM10
SO2
Ministry of Environment
Kootenay Region
ENVIRONMENTAL QUALITY
Airshed
Ambient Air Quality Monitoring Report
Castlegar, British Columbia
Dates of Operation
Kokanee Park
Nelson
July 2001 – August 2002
March 1985 – present
Radium
Revelstoke
July 1998 - 2007
May 1989 – present
Skookumchuck
August 1987 – July 2005
Slocan
April 1985 – May 1986
November 1991 - present
Sparwood
January 1982 – present
Trail (15 sites)
February 1970 - present
Ymir
May, 1984 – February 1988
53
Parameters
Measured
PM10
TSP
PM10
PM2.5
O3
Met
PM10
PM10
PM2.5
Dustfall
Met
TRS
Met
TSP
PM10
Dustfall
TSP
PM10
PM2.5
Dustfall
TSP
PM10
PM2.5
Dustfall
Metals
CO
NO
NO2
O3
SO2
Met
TSP
Dustfall
Ministry of Environment
Kootenay Region
ENVIRONMENTAL QUALITY
Airshed
Ambient Air Quality Monitoring Report
Castlegar, British Columbia
Month
Day
January
February
March
April
May
June
5
11
17
23
29
4
10
16
22
28
6
12
18
24
30
5
11
17
23
29
5
11
17
23
29
4
10
16
22
28
PM10
(μg/m3)
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
9
ND
ND
ND
ND
ND
ND
ND
34
ND
35
24
July
August
September
October
November
December
4
10
16
22
28
3
9
15
21
27
2
8
14
20
26
2
8
14
20
26
1
7
13
19
25
1
7
13
19
25
31
2
35
25
25
29
ND
ND
ND
ND
ND
10
24
42
20
46
16
24
19
24
24
ND
40
20
37
ND
22
78
20
4
38
44
Values in bold depict days with PM10 exceeding NAAQ objectives.
ND = No data available for the day.
54
Ministry of Environment
Kootenay Region
ENVIRONMENTAL QUALITY
Appendix H1 - PM10 Data for 1990
Ambient Air Quality Monitoring Report
Castlegar, British Columbia
Month
Day
January
February
March
April
May
June
6
12
18
24
30
5
11
17
23
1
7
13
19
25
31
6
12
18
24
30
6
12
18
24
30
5
11
17
23
29
PM10
(μg/m3)
4
35
56
46
ND
20
28
26
61
9
50
60
27
15
35
22
29
62
ND
13
17
17
33
15
17
30
11
ND
21
ND
July
August
September
October
November
December
5
11
17
23
29
4
10
16
22
28
3
9
15
21
27
3
9
15
21
27
2
8
14
20
26
2
8
14
20
26
ND
29
17
36
22
22
12
26
20
15
16
12
20
19
69
26
39
40
29
23
21
41
19
16
18
29
18
8
18
11
Values in bold depict days with PM10 exceeding NAAQ objectives.
ND = No data available for the day.
55
Ministry of Environment
Kootenay Region
ENVIRONMENTAL QUALITY
Appendix H2 - PM10 Data for 1991
Ambient Air Quality Monitoring Report
Castlegar, British Columbia
Month
Day
January
February
March
April
May
June
1
7
13
19
25
31
6
12
18
24
1
7
13
19
25
31
6
12
18
24
30
6
12
18
24
30
5
11
17
23
29
PM10
(μg/m3)
ND
ND
ND
ND
ND
ND
23
14
14
50
28
26
64
18
46
36
13
16
7
27
13
55
21
ND
ND
20
30
24
20
27.6
6.5
July
August
September
October
November
December
5
11
17
23
29
4
10
16
22
28
3
9
15
21
27
3
9
15
21
27
2
8
14
20
26
2
8
14
20
26
16
12
28
12
25
27
19
18
11
30
25
15
13
20
12
41
25
14
26
15
20
ND
23
24
ND
13
31
31
32
22
Values in bold depict days with PM10 exceeding NAAQ objectives.
ND = No data available for the day.
56
Ministry of Environment
Kootenay Region
ENVIRONMENTAL QUALITY
Appendix H3 - PM10 Data for 1992
Ambient Air Quality Monitoring Report
Castlegar, British Columbia
Month
Day
January
February
March
April
May
June
1
7
13
19
25
31
6
12
18
24
2
8
14
20
26
1
7
13
19
25
1
7
13
19
25
31
6
12
18
24
30
PM10
(μg/m3)
5
8
6
83
53
19
20
33
27
16
21
38
33
23
37
64
15
15
17
8
ND
ND
ND
ND
ND
ND
26
18
38
26
22
July
August
September
October
November
December
6
12
18
24
30
5
11
17
23
29
4
10
16
22
28
4
10
16
22
28
3
9
15
21
27
3
9
15
21
27
28
14
17
25
ND
56
21
29
24
11
36
46
37
33
43
47
18
18
44
ND
31
32
35
ND
ND
ND
12
26
35
15
Values in bold depict days with PM10 exceeding NAAQ objectives.
ND = No data available for the day.
57
Ministry of Environment
Kootenay Region
ENVIRONMENTAL QUALITY
Appendix H4 - PM10 Data for 1993
Ambient Air Quality Monitoring Report
Castlegar, British Columbia
Month
Day
January
February
March
April
May
June
2
8
14
20
26
1
7
13
19
25
3
9
15
21
27
2
8
14
20
26
2
8
14
20
26
1
7
13
19
25
PM10
(μg/m3)
24
34
54
24
40
43
18
21
14
10
34
102
52
18
30
58
16
23
31
18
18
ND
31
13
28
32
22
ND
12
28
July
August
September
October
November
December
1
7
13
19
25
31
6
12
18
24
30
5
11
17
23
29
5
11
17
23
29
4
10
16
22
28
4
10
16
22
28
20
24
28
ND
ND
ND
ND
ND
25
24
18
8
4
21
30
27
23
17
20
15
18
21
ND
ND
ND
20
11
20
32
44
16
Values in bold depict days with PM10 exceeding NAAQ objectives.
ND = No data available for the day.
58
Ministry of Environment
Kootenay Region
ENVIRONMENTAL QUALITY
Appendix H5 - PM10 Data for 1994
Ambient Air Quality Monitoring Report
Castlegar, British Columbia
Month
Day
January
February
March
April
May
June
3
9
15
21
27
2
8
14
20
26
4
10
16
22
28
3
9
15
21
27
3
9
15
21
27
2
8
14
20
26
PM10
(μg/m3)
17
6
25
12
29
25
15
26
16
29
19
21
28
8
40
22
14
11
29
22
14
53
67
ND
40
44
17
11
10
28
July
August
September
October
November
December
2
8
14
20
26
1
7
13
19
25
31
6
12
18
24
30
6
12
18
24
30
5
11
17
23
29
5
11
17
23
29
21
29
ND
37
14
12
10
15
12
24
22
17
29
15
ND
14
22
16
11
29
11
26
20
10
43
25
6
17
20
22
29
Values in bold depict days with PM10 exceeding NAAQ objectives.
ND = No data available for the day.
59
Ministry of Environment
Kootenay Region
ENVIRONMENTAL QUALITY
Appendix H6 - PM10 Data for 1995
Ambient Air Quality Monitoring Report
Castlegar, British Columbia
Month
Day
January
February
March
April
May
June
4
10
16
22
28
3
9
15
21
27
4
10
16
22
28
3
9
15
21
27
3
9
15
21
27
2
8
14
20
26
PM10
(μg/m3)
32
16
22
10
5
15
22
14
12
46
12
23
39
22
17
ND
ND
ND
ND
ND
21
9
ND
16
17
14
20
17
11
16
July
August
September
October
November
December
2
8
14
20
26
1
7
13
19
25
31
6
12
18
24
30
6
12
18
24
30
5
11
17
23
29
5
11
17
23
29
ND
18
18
13
19
19
ND
ND
ND
23
15
12.5
11.9
11.3
7.3
13.1
15.3
13.3
15.8
16
7
20.3
11.9
16.4
10.8
ND
ND
ND
ND
8
14.8
Values in bold depict days with PM10 exceeding NAAQ objectives.
ND = No data available for the day.
60
Ministry of Environment
Kootenay Region
ENVIRONMENTAL QUALITY
Appendix H7 - PM10 Data for 1996
Ambient Air Quality Monitoring Report
Castlegar, British Columbia
Month
Day
January
February
March
April
May
June
4
10
16
22
28
3
9
15
21
27
5
11
17
23
29
4
10
16
22
28
4
10
16
22
28
3
9
15
21
27
PM10
(μg/m3)
23.8
27.1
37.7
31.1
2.8
ND
9.1
28.1
57.7
25.2
48.2
43.9
37
39.6
24.3
41.4
32.4
14.8
14.5
8.5
5.6
18.2
16.6
13.9
13.5
12.3
14.7
13.2
6.8
9.8
July
August
September
October
November
December
3
9
15
21
27
2
8
14
20
26
1
7
13
19
25
1
7
13
19
25
31
6
12
18
24
30
6
12
18
24
30
13.6
8.3
16.4
15.5
24
8
ND
28
28
10
13
10
9
11
28
25
41
25
ND
31
18
31
30
28
22
20
9
37
14
13
28
Values in bold depict days with PM10 exceeding NAAQ objectives.
ND = No data available for the day.
61
Ministry of Environment
Kootenay Region
ENVIRONMENTAL QUALITY
Appendix H8 - PM10 Data for 1997
Ambient Air Quality Monitoring Report
Castlegar, British Columbia
Month
Day
January
February
March
April
May
June
5
11
17
23
29
4
10
16
22
28
6
12
18
24
30
5
11
17
23
29
5
11
17
23
29
4
10
16
22
28
PM10
(μg/m3)
14
28
16
14
24
9
38
21
18
26
24
22
22
ND
13
ND
ND
ND
ND
ND
25
ND
16
ND
16
19
33
12
13
25
July
August
September
October
November
December
4
10
16
22
28
3
9
15
21
27
2
8
14
20
26
2
8
14
20
26
1
7
13
19
25
1
7
13
19
25
31
47
36
21
ND
39
63
38
46
71
49
29
21
18
8
8
ND
18
22
24
37
33
26
25
20
9
8
16
12
24
15
13
Values in bold depict days with PM10 exceeding NAAQ objectives.
ND = No data available for the day.
62
Ministry of Environment
Kootenay Region
ENVIRONMENTAL QUALITY
Appendix H9 - PM10 Data for 1998
Ambient Air Quality Monitoring Report
Castlegar, British Columbia
Month
Day
January
February
March
April
May
June
6
12
18
24
30
5
11
17
23
1
7
13
19
25
31
6
12
18
24
30
6
12
18
24
30
5
11
17
23
29
PM10
(μg/m3)
25
15
14
29
24
24
103
42
25
40
35
12
25
16
13
19
19
30
31
13
13
20
8
19
12
14
10
22
14
17
July
August
September
October
November
December
5
11
17
23
29
4
10
16
22
28
3
9
15
21
27
3
9
15
21
27
2
8
14
20
26
2
8
14
20
26
8
21
16
17
25
6
22
14
14
22
18
19
ND
28
9
ND
13
18
29
16
23
28
15
19
15
12
22
16
ND
ND
Values in bold depict days with PM10 exceeding NAAQ objectives.
ND = No data available for the day.
63
Ministry of Environment
Kootenay Region
ENVIRONMENTAL QUALITY
Appendix H10 - PM10 Data for 1999
Ambient Air Quality Monitoring Report
Castlegar, British Columbia
Month
Day
January
February
March
April
May
June
1
7
13
19
25
31
6
12
18
24
1
7
13
19
25
31
6
12
18
24
30
6
12
18
24
30
5
11
17
23
29
PM10
(μg/m3)
53
27
16
30
11
21
26
26
88
34
31
20
37
13
35
33
10
26
ND
ND
27
11
11
21
21
9
11
6
14
15
14
July
August
September
October
November
December
5
11
17
23
29
4
10
16
22
28
3
9
15
21
27
3
9
15
21
27
2
8
14
20
26
2
8
14
20
26
11
13
16
12
9
18
32
14
ND
13
6
8
16
5
19
19
21
16
13
17
24
24
19
27
15
17
27
ND
ND
19
Values in bold depict days with PM10 exceeding NAAQ objectives.
ND = No data available for the day.
64
Ministry of Environment
Kootenay Region
ENVIRONMENTAL QUALITY
Appendix H11 - PM10 Data for 2000
Ambient Air Quality Monitoring Report
Castlegar, British Columbia
Month
Day
January
February
March
April
May
June
1
7
13
19
25
31
6
12
18
24
2
8
14
20
26
1
7
13
19
25
1
7
13
19
25
31
6
12
18
24
30
PM10
(μg/m3)
19
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
11
17
23
7
15
20
12
22
10
9
6
8
12
12
July
August
September
October
November
December
6
12
18
24
30
5
11
17
23
29
4
10
16
22
28
4
10
16
22
28
3
9
15
21
27
3
9
15
21
27
21
ND
9
10
5
9
ND
38
7
16
8
13
15
12
9
8
12
17
10
ND
ND
ND
ND
ND
ND
13
21
26
7
5
Values in bold depict days with PM10 exceeding NAAQ objectives.
ND = No data available for the day.
65
Ministry of Environment
Kootenay Region
ENVIRONMENTAL QUALITY
Appendix H12 - PM10 Data for 2001
Ambient Air Quality Monitoring Report
Castlegar, British Columbia
Month
Day
January
February
March
April
May
June
2
8
14
20
26
1
7
13
19
25
3
9
15
21
27
2
8
14
20
26
2
8
14
20
26
1
7
13
19
25
PM10
(μg/m3)
11
16
11
9
13
21
10
70
19
31
31
13
21
16
14
20
17
17
11
16
59
12
9
15
16
13
15
28
21
19
July
August
September
October
November
December
1
7
13
19
25
31
6
12
18
24
30
5
11
17
23
29
5
11
17
23
29
4
10
16
22
28
4
10
16
22
28
12
18
21
23
28
11
16
16
20
21
14
ND
ND
ND
ND
ND
11
14
21
23
11
25
14
31
21
13
7
14
10
7
12
Values in bold depict days with PM10 exceeding NAAQ objectives.
ND = No data available for the day.
66
Ministry of Environment
Kootenay Region
ENVIRONMENTAL QUALITY
Appendix H13 - PM10 Data for 2002
Ambient Air Quality Monitoring Report
Castlegar, British Columbia
Month
Day
January
February
March
April
May
June
3
9
15
21
27
2
8
14
20
26
4
10
16
22
28
3
9
15
21
27
3
9
15
21
27
2
8
14
20
26
PM10
(μg/m3)
6
11
7
10
20
16
30
36
13
23
20
15
ND
ND
16
11
11
11
17
8
10
12
17
17
16
14
17
12
17
21
July
August
September
October
November
December
2
8
14
20
26
1
7
13
19
25
31
6
12
18
24
30
6
12
18
24
30
5
11
17
23
29
5
11
17
23
29
18
22
15
20
25
32
27
43
ND
60
28
40
13
21
16
37
30
9
17
17
12
26
11
11
19
14
12
11
15
11
ND
Values in bold depict days with PM10 exceeding NAAQ objectives.
ND = No data available for the day.
67
Ministry of Environment
Kootenay Region
ENVIRONMENTAL QUALITY
Appendix H14 - PM10 Data for 2003
Ambient Air Quality Monitoring Report
Castlegar, British Columbia
Month
Day
January
February
March
April
May
June
4
10
16
22
28
3
9
15
21
27
4
10
16
22
28
3
9
15
21
27
3
9
15
21
27
2
8
14
20
26
PM10
(μg/m3)
ND
20
20
15
17
15
26
24
ND
13
31
33
42
79
23
28
19
8
15
20
19
11
18
12
13
18
17
11
18
18
July
August
September
October
November
December
2
8
14
20
26
1
7
13
19
25
31
6
12
18
24
30
6
12
18
24
30
5
11
17
23
29
5
11
17
23
29
18
19
24
14
53
33
12
29
28
9
18
12
13
10
24
13
28
25
2
23
17
25
9
12
28
ND
12
17
19
16
13
Values in bold depict days with PM10 exceeding NAAQ objectives.
ND = No data available for the day.
68
Ministry of Environment
Kootenay Region
ENVIRONMENTAL QUALITY
Appendix H15 - PM10 Data for 2004
Ambient Air Quality Monitoring Report
Castlegar, British Columbia
Month
Day
January
February
March
April
May
June
4
10
16
22
28
3
9
15
21
27
5
11
17
23
29
4
10
16
22
28
4
10
16
22
28
3
9
15
21
27
PM10
(μg/m3)
ND
6
8
19
14
26
30
18
24
24
27
18
11
14
10
10
15
12
26
13
16
16
14
6
21
13
ND
ND
23
9
July
August
September
October
November
December
3
9
15
21
27
2
8
14
20
26
1
7
13
19
25
1
7
13
19
25
31
6
12
18
24
30
6
12
18
24
30
11
7
21
18
22
13
20
10
12
15
9
19
9
12
10
ND
ND
ND
ND
ND
ND
10
13
34
10
14
13
20
22
10
14
Values in bold depict days with PM10 exceeding NAAQ objectives.
ND = No data available for the day.
69
Ministry of Environment
Kootenay Region
ENVIRONMENTAL QUALITY
Appendix H16 - PM10 Data for 2005
Ambient Air Quality Monitoring Report
Castlegar, British Columbia
Month
Day
January
February
March
April
May
June
5
11
17
23
29
4
10
16
22
28
6
12
18
24
30
5
11
17
23
29
5
11
17
23
29
4
10
16
22
28
PM10
(μg/m3)
12
13
23
10
11
8
16
8
15
11
8
13
11
14
18
ND
ND
8
9
13
16
20
27
10
9
11
ND
13
10
ND
July
August
September
October
November
December
4
10
16
22
28
3
9
15
21
27
2
8
14
20
26
2
8
14
20
26
1
7
13
19
25
1
7
13
19
25
31
ND
12
14
29
36
25
29
28
45
26
23
ND
7
9
18
14
7
20
8
15
24
15
12
13
10
16
21
8
ND
ND
12
Values in bold depict days with PM10 exceeding NAAQ objectives.
ND = No data available for the day.
70
Ministry of Environment
Kootenay Region
ENVIRONMENTAL QUALITY
Appendix H17 - PM10 Data for 2006
Ambient Air Quality Monitoring Report
Castlegar, British Columbia
Month
Day
January
February
March
April
May
June
6
12
18
24
30
5
6
11
17
23
1
7
13
19
25
31
6
12
18
24
30
6
12
18
24
30
5
11
17
23
29
PM10
(μg/m3)
ND
ND
16
12
4.3
16
15
60
10
7
28
26
17
6
17
21
16
12
18
10
11
17
20
8
ND
ND
ND
ND
ND
ND
ND
July
August
September
October
November
December
5
11
17
23
29
4
10
16
22
28
3
9
15
21
27
3
9
15
21
27
2
8
14
20
26
2
8
14
20
26
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
18
Values in bold depict days with PM10 exceeding NAAQ objectives.
ND = No data available for the day.
71
Ministry of Environment
Kootenay Region
ENVIRONMENTAL QUALITY
Appendix H18 - PM10 Data for 2007