Six Classes We can reduce harmful chemicals for a healthier world. Periodic table of elements 2 9 F 17 Cl 35 Br Six classes 1. Highly fluorinated chemicals water and oil repellants, surfactants… 2. Antimicrobials triclosan, triclocarban… 3. Flame retardants brominated, chlorinated, phosphate 4. Bisphenols and phthalates plastic additives… 5. Organic solvents benzene, methylene chloride... 6. Certain metals lead, mercury, chromium, cadmium, arsenic… 3 Six Classes 1. Highly Fluorinated Chemicals (Fluorochemicals) Dr. Jennifer A. Field Department of Environmental and Molecular Toxicology Oregon State University Corvallis, Oregon 97331 4 Chemical Personality and C-F bonds • Atoms share electrons in the form of bonds that glue molecules together • C-F bonds are the strongest bonds in nature • Unique properties • oil and water repellency • resistance to breakdown in the environment and under harsh conditions O O PFOS F S F C C F F F F F C F F C F F F C C F C F F F - O C F C F C F F F C F F C F F C O C F F - F F PFOA O C F C F C F F F 5 Fluorochemicals • Do not occur in nature; only due to manufacture, use, and disposal • C8 forms (PFOS and PFOA) are of particular interest • Produced in large quantities since 1940s • Well studied • Associated with wide range of human health problems • C4/C6 produced since the 1940s and share family structure and properties, but almost no information on health effects 6 Where Fluorochemicals are Used • • • • • • • Carpeting Upholstery Apparel Waxes (ski and floor) Food packaging materials Non-stick cookware Dental floss 7 Pathways to the Environment Indoor and Outdoor Air • Semi-volatile forms migrate out from products • Higher indoor air concentrations move outdoors Surface and Ground Water • Industrial discharge • Wash-off from treated apparel • Wastewater treatment does not remove PFOS/PFOA or shorter-chain analogs Solid Waste Disposal • Treated materials sent to landfills • Liquid waste (leachates) sent to wastewater treatment plants or percolate into ground 8 Sources and Exposure Pathways breastmilk dust/fibre goods cord blood Human exposure PFAS producers/ PFAS-using factories Prenatal/infant exposure Landfill leachate manufacturer waste solid WWTP liquid Adapted from Oliaei 2013, Environ Pollut Res 9 Found Globally Today • Surface Waters (lakes, rivers, ocean) • Sediments & soils • Groundwater (drinking water source) • Air, Rain, Snow in urban and remote locations • Marine and land-based wildlife 10 Human Toxicology • PFOS and PFOA persist in the body for years • Health effects linked to exposure to PFOA: • Kidney, prostate, ovarian, and testicular cancer • Thyroid disease • Delayed puberty, decreased fertility (women) and early menopause • Reduced testosterone levels • Reduced immune response in children • Elevated cholesterol 11 PFOS and PFOA Replacements • Shorter chains (C4/C6) offered as ‘alternatives’ but are members of the PFOS/PFOA families or close cousins • C4/C6 now found in surface waters, groundwater, wastewater, & seawater • C4/C6 not bioaccumulative but are persistent, which is a ‘family trait’ • Very limited toxicology data on short chain (C4/C6) family members - Increasing C6 levels in human blood - Causes changes in cells associated with tumors 12 Take Home Points • Once produced, fluorochemicals stay on the planet for a very, very long time. • Widespread contamination of water, food, and soils; distributed globally by air and water circulation. • Current understanding of human health effects developed for only PFOS & PFOA. • Changing to other forms such as C6 and C4 may appear as a quick fix for the marketplace but there is no data to show they are safer. 13 What can we do to reduce harm? • Do we need them for performance/protection in all current applications? –Apparel –Carpeting –Food packaging • Support research to find safer alternatives –Materials innovation taking a page from nature (bio-mimicry) –Green chemistry 14 Follow-up questions – Are there fluorochemicals in the products you manufacture, sell, or use? – What functions do they serve? – How necessary are these functions? – What alternatives have you investigated? – Would you be interested in continuing this discussion? If so, contact: Erika Houtz, [email protected] 15
© Copyright 2024