How to measure health relevant indicators? (Ultra)fine particles Jeroen Staelens (VMM; Joaquin) Susanne Bastian (LfULG; UFIREG) Tackling tomorrow's air pollution today - a solution oriented approach - 21 May 2014 - Leicester Outline Ultrafine particles (UFP) • Introduction: UFP • Measurement principles and instruments • Intra-urban variation (Antwerp; Joaquin) • Large-scale variation (Central Europe; UFIREG) • Challenges • Health relevance • Conclusions Introduction • Air quality and health • • • • • Heavy metals, PAHs, … Ozone (O3) Nitrogen dioxide (NO2) Particulate matter (PM) … • Particulate matter • Mixture of solid and liquid particles in air • Varying in size, shape, composition, … (Ultra)fine particles • Particulate matter → µg per m3 • Classified according to size • • • • Coarse (PM10) Fine (PM2.5) Submicron Ultrafine < 10 µm diameter < 2.5 µm < 1 µm < 0.1 µm = 100 nm • Particle number → particles per cm3 • UFP: low mass, high number • Why measure (ultra)fine particles? • Novel health-relevant air quality variable • Health effects demonstrated but not well understood http://www.tesa-clean-air.com (http://www.epa.gov) Typical urban aerosol Number UFP Surface area Volume or mass ~ D2 ~ D3 (Seinfield and Pandis 2006) Measuring ultrafine particles in ambient air • No air quality legislation on UFP • No standardisation yet • No systematic environmental monitoring • Recent development of monitoring instruments • Aerosol sampling • Losses possible due to gravimetric and electrostatic forces, impaction and diffusion • Particle size depends on humidity → drying • Impactor/cyclone to remove larger particles Which metric? → Surface area concentration • Particle number concentration • Total PNC • Size distribution → concentration for different size classes 16 000 dN/dlogDp (particles cm-3) 14 000 12 000 10 000 8 000 6 000 4 000 2 000 0 10 100 Particle Diameter (nm) 1000 How to measure the total number of particles? • Optical particle counter ? • Light scattering by single particles • But: UFP too small for detection • Condensation particle counter (CPC) • Particle enlarged via condensation of vapour onto a single particle (www.machinerylubrication.com) > 1 µm • Instruments • CPC using butanol or water • Typically: 5-10 nm to 1 µm • Fast measurements (1 s) TSI-3783 or EPC How to measure the size distribution of particles? 1. Charger (neutralizer) • Particles in known charge distribution 2. Electrostatic classification • Size classification based on electrical mobility (~ diameter and charge) 3. Particle counter • Particle number per mobility class → Data inversion algorithm Particle mobility → diameter Instruments for particle size distribution • SMPS (Grimm, TSI, Tropos, …) • Bipolar diffusion charger (85Kr, 64Ni, … source) • DMA • Scan time of 5 to 10 min • 10 to 800/1000 nm (30-200 size classes) • Butanol CPC • UFP monitor (TSI 3031) • Unipolar charger (Corona needle) • DMA • Scan time of 10 min • 20 to 200 nm (5 size classes) • Electrometer detection Intra-urban variation in UFP (Antwerp; Joaquin) • Joaquin project • Measurement sites and instruments for Antwerp 2013 campaign • Total particle number concentration • Day profile at 5 sites • Temporal correlation between sites • PNC per size range • • • • Particle size distribution Spatial variation between sites Temporal correlation between sites Correlation with NO2 Joaquin project • Joint Air Quality Initiative • www.joaquin.eu • INTERREG IVB NWE project with 16 partners in BE, NL, FR, UK • Aim: to support health-oriented air quality policies in Europe • 3 themes • Measurements • Policy measures • Communication • Measurements • Composition and oxidative potential of PM10 • Continuous long-term measurements of UFP, BC and gases (NOx) at 4 urban sites (Antwerp, Amsterdam, Leicester, London) + 1 mobile station • Relationships between air quality parameters Intra-urban UFP variability (4 Feb - 4 March 2013) Suburban • Tropos SMPS • EPC (wk 3 & 4) Public park • Tropos SMPS • EPC (wk 3 & 4) Urban • UFP monitor • EPC (wk 1 & 2) Monitoring station / Urban background • Grimm SMPS • EPC Ring road • UFP monitor • EPC (wk 1 & 2) Day profile total PNC on week days (week 1 & 2) Day profile total PNC on week days (week 3 & 4) Correlation total PNC - Monitoring station vs. urban & ring Urban Ring +97% +120% Correlation total PNC - Monitoring station vs. suburban & park Public park -7% Suburban -39% Particle size distribution (week days) Particle Number Concentration per size range (# cm-3) 7 000 Size distributions vary depending on intensity of / proximity to traffic source 6 000 5 000 4 000 Monitoring Station Urban Ring Road 3 000 Suburban Public Park 2 000 1 000 0 20-30 nm 30-50 nm 50-70 nm 70-100 nm 100-200 nm >200 nm Size Range Spatial variation of PNC (COD) 0.6 Monitoring Station vs Suburban 0.5 Monitoring Station vs Public Parc Coefficient of Divergence (COD) Monitoring Station vs Ring Monitoring Station vs Urban 0.4 0.3 0.2 0.1 0.0 20-30 nm 30-50 nm 50-70 nm Size Range 70-100 nm 100-200 nm Temporal correlation of PNC 1.0 0.9 Correlatation coefficient 0.8 0.7 0.6 0.5 0.4 0.3 Monitoring Station vs Suburban 0.2 Monitoring Station vs Public Parc Monitoring Station vs Ring 0.1 Monitoring Station vs Urban 0.0 20-30 nm 30-50 nm 50-70 nm Size Range 70-100 nm 100-200 nm Correlation between NO2 and PNC 8000 Particle Number concentration (cm-3) 7000 6000 5000 4000 20-30 nm R² = 0.8548 30-50 nm R² = 0.9357 50-70 nm R² = 0.8665 70-100 nm R² = 0.7429 3000 100-200 nm R² = 0.4283 2000 1000 0 0 20 40 60 NO2 (µg/m3) 80 100 Large-scale variation in UFP (Central Europe) • UFIREG project • Measurement sites and instruments • Particle number concentration (PNC) of different size classes • Day profile at 4 sites • Weekdays vs. weekend • Spatial correlation • Temporal correlation • New particle formation • Impact of air mass origin UFIREG project • Ultrafine Particles – an evidence based contribution to the development of regional and European environmental and health policy • www.ufireg-central.eu • Interreg IVB Central Europe project with 7 partners in D, CZ, SLO, UA • Aim: Improvement of air quality and minimalization of health risks • Themes • Measurements of UFP • Health studies (short-term effects on mortality and morbidity) • Communication/Dissemination • Measurements • Continuous long-term measurements of UFP (and PM, gases and meteorology) at 5 urban background sites • Relationships between air quality parameters Sites and instrumentation TSI-SMPS (TROPOS update) and UFP 330 since 04/2012 TROPOS-SMPS since 2011 TROPOS-TDMPS since 2004 and UFP 330 since 5/2012 TROPOS-SMPS since 01/2013 TROPOS-SMPS since 04/2012 Day profile Dresden Friday Weekend Particle number per cm³ Monday - Thursday ? Hour 30-50 nm 50-100 nm 100-200 nm Preliminary results Day profiles other cities (Monday - Thursday) Ljubljana Prague 30-50 nm 50-100 nm Chernivtsi 100-200 nm Preliminary results Size distributions - 2013 2500 Particle number per cm³ 2000 Dresden 1500 Prague Ljubljana Chernivtsi 1000 Dresden traffic site 500 0 20-30 nm 30-50 nm 50-70 nm 70-100 nm 100-200 nm > 200 nm Preliminary results Spatial variation of PNC (COD) Preliminary results May 2012 to April 2014 24 hours average 1 hour average Temporal correlation of PNC Preliminary results May 2012 to April 2014 24 hours average 1 hour average New particle formation (NPF) Particle number per cm³ Characteristics of NPF days • High global radiation • Low relative humidity • Lower [NO2] than on other days 80 60 90 70 0 3010 4020503060 4070 50 Dresden DresdenMay May2012 2012to to April April 2013 2013 10-18:00 humidity Relative 10-18:00 NO2 Global radiation in W/m² Global radiation NPF NPF NoNPF NPF No Undefined Undefined New particle formation – annual cycle Health relevance questionable Analysis done by Nadezda Zikova, ICPF Prague Meteorological cluster analysis PM10 exceedances Dresden based on 96 h back trajectories, pollutants averaged from 10-18 hrs Analysis done by Benjamin Hage, TROPOS Challenges in measuring UFP • Still relatively new measurement technique • Little experience in long-term application in routine networks • Need of very frequent quality assurance > Data availability  • Complex (and time-consuming) data validation • Still high uncertainties, especially in the smallest size range • UFIREG: no online data > no regular publishing • Butanol emissions of instruments with high size-resolution • Problematic for benzene measurements, but can be mitigated by catalytic oxidation (oven) Quality assurance Measure Frequency Visual check of measurements (via remote access) Once per day Maintenance (HV and size calibration, flow rate checks, butanol refill) Once per month Data validation Once per month Check of data plausibility Once per month On-site comparison Twice per year Complete check of the instrument Once per year Laboratory versus on-site comparison 13.08. 2011 – Laboratory Dresden 15.-18.08. 2011 - Station 10000 6000 SMPS Ref-1 SMPS ref_1 SMPS_wi SMPS Ref-2 SMPS Ref-3 8000 -3 4000 dN/dlogDp in cm dN/dlogDp in p./cm 3 SMPS BfUL 2000 Within 10% range 6000 4000 Out of 10% range QK Winckelmannstraße 2000 Messung: Ambientmessung Zeitraum: 15.08.11 20:00 - 18.08.11 08:00 0 0 10 100 Dp in nm 1000 10 100 Dp in nm 800 Round-Robin tests (RRT) • No concentration „test aerosol“ Station 1 Station 2 • JOAQUIN: • RRT with Mobile Station • Two parallel instruments Reference/ Control Instrument Station 5 Station 3 Station 4  On-site instrument comparison = only possibility for quality check • UFIREG: • RRT with TROPOS Reference system • Automated function control units Data for health studies (UFIREG codebooks) „Codebook Exposure Variables“ „Codebook Health Outcomes“ • Daily averages, -maxima, -minima from air pollution and meteorological parameters, NPF • Different lag times and lag sums • All-cause hospital admissions and allcause mortality on a daily basis • Cause-specific health outcomes • Focus on cardiovascular and respiratory hospital admissions and mortality „Codebook Confounder“ • Consideration of public holidays, weekends, vacations and seasons • Influence of age, gender and region • Delayed data availability • Consideration of waves of influenza Analysis for 2012 in German cities starts now Health relevance Coarse und fine particles Simplified hypothesis following toxicological hints Inflammation Neurohumoral mechanisms Ultrafine particles Translocation Little epidemiological evidence so far Pictures: wikipedia Conclusions • PNC in urban areas depends strongly on • Meteorological conditions • Different sources (traffic, domestic heating, long-range transport, etc.) → Important: everyday life of people • Cityscape • Extensive quality assurance is essential for comparable UFP measurements • Differences in short-term health effects of PM and UFP Thank you ! Joaquin - www.joaquin.eu Supported by INTERREG IVB North West Europe UFIREG - www.ufireg-central.eu Supported by INTERREG IVB Central Europe Questions?