Document 3Njap89d54keBdLZqGpXLKnvx

ARRA - Environmental fate of Fluorotelomer Based Substances Derek Muir Aquatic Ecosystem Protection Research Division Water Science and Technology Directorate Science and Technology Branch Environment Canada Burlington ON Environment Environnement Canada Canada 000134 Outline 1) Conversion of `fluorotelomer alcohols' to PFCAs Atmospheric degradation of "Residual FTOHs" Atmospheric measurements (air, precipitation) Biological degradation of FTOHs Biodegradation of fluorotelomer polymers? 2) Persistence and bioaccumulation of FTOHs and PFCAs Effect of chain length on bioaccumulation Bioaccumulation & magnification of PFCAs in food webs 3) Toxicology and risk assessment of PFCAs mammalian; aquatic 4) Trends of PFCAs in the environment Geographical and temporal trends of PFCAs PFCA (C8-C15) chain length patterns Investigations of branched chain PFCA isomers 000135 Overview of the Environmental fate pathways of the fluorotelomer polymers and residuals FC F,C lllli Volatile FTOH residuals -- \j A tm o sp h e ric* ^ degradation to!i!1'}ii //, RFCAs (C2-Cty-h)/ Nonvolatlles: washoff/disposal of Bulk material residuals, polymers, to landfill monomers and degradation products Sediment, Soil, Sludge.,. B io ta 1) Conversion of `fluorotelomer alcohols (FTOHs)' to PFCAs 000X37 Profiles of residual unbound fluorotelomer alcohols (FTOHs) detected in 6 materials that include fluorotelomer based polymers or monomers (Dinglasan and Mabury ES&T In press) Values are expressed as percent of total residuals measured. Fluorinated Material % of dry weight Polyfox-L-Diol 0.11 0.03 Percent (% ) of total residuals TeflonTM Advance 0.34 0.20 ZonylTM FSO 100 1.03 0.61 ZonylTM FSE 3.80 1.09 Polyfox-L-diol Teflon Advance Zonyl FSO 100 Zonyl FSE 8:2 Methacrylate Monomer MotomasterTM Motomaster Windshield Washer 8:2 Windshield Methacrylate Washer 0.04 0.01 0.36 0.01 000138 Atmospheric degradation of the FTOHs: Reaction with OH radicals yields aldehydes and acids and can "unzip" the perfluorinated chain (Ellis et al. 2003; Hurley et al. 2004) FF. F R F A V> H F ffffffhh 8:2 FTOH Atmospheric Lifetime = 20 d FT unsaturated acids E. f o OH F FH H Perfluoro aldehyde E. F R>* \ \ ii FF O >90% Attack on a hydrogens; H-Bond deactivates OH abstraction OH FT-Aldehyde ' ^ Lifetime = 20 d E F F. F F. F F. F oII .,,C V S c W V - -e F FFFFFFHh n p&Bm V PFCAs Atmospheric Carbonyl Lifetime - fluooride ii R F 20-30 d ^OH FxCxF iFV F " o 10:2 and 12:2 FTOHs should yield similar products 000.139 000140 Atmospheric concentrations of FTOHs (Stock et al. 2004; Stock 2006 unpublished) Implies emissions of 100-1000 tonnes/yr of FTOHs - which in reasonable agreement with estimated FTOH residuals in FTpolymers (Prevedouros et al 2006) 6-2 FTOH 10-2 FTOH 8-2 FTOH 300 Griffin, GA 200- 2001 n=3 100- i1 <LOQ 6-2 FTOH 10-2 FTOH 8-2 FTOH FTOHs <10 to 135 pg/m3 50 40 L(>ng Point, Of i 30 - 20 2001 n=3 10 0 L i __ 6-2 FTOH 10-2 FTOH 8-2 FTOH 000141 p 00 Evidence of PFCAs & Fluorotelomer Acids in Rainwater from Three Locations, May-July 1 9 9 9 (Scott etai. 2006 in prep) SW Delaware 8 NW Vermont NE New York 7 N=io per site l \i Verrnon ^ NE New Yorkl SW Delaware O Major urban areas Precip sampling Cone (ng/L) I0 PFHpA PFOA PFiNA C7 C8 C9 PFDA C10 1. l PDUA C11 PFDoA C12 8F:T2A 1 F1T0A:2 F8T:2U-Aa,p * Carboxylates ---------------------- -Telomer acids- 000142 PFCAs & Fluorotelomer Acids in Rainwater from Two Toronto area locations, Nov-Dec 2003 (Scott et al. 2006 in prep) ' '" 5.0 Cone (ng/L) 4.0 O Major urban areas Precip sampling 3.0 2.0 1.0 0.0 8 2 6 2 8 2 10 2C8 C9 C10 C11 C12 6:2- : - 10:2- : - : - :- FTA FTA FTA a,p- a,p- a,p- FTUA FTUA FTUA 000143 Global modelling of the degradation and transport of FTOHs (Wallington et al. ES&T 2006) Summed concentration of 8:2 FTOH and all of its degradation products at 50 m in altitude for (a) January and (b) July. Concentration of PFOA (in molecule cm 3) at 50 m in altitude for (a) January and (b) July. Graphics copied directly from Wallington et al. omitted to make the file smaller. Please see the original paper Figures 2-5. 000144 Biodegradation of 8:2-FTOH by a mixed microbial system Dinglasan et al ES&T 2004 Degradation of 8:2 FTOH (Days 1-81). Fluoroteiomer unsaturated acid (FTUCA) is major product. Wang et al ES&T 2005 a,b have also shown biodegradation of 8:2FTOH using 14C-labelled chemical - which allowed more products to be identified 000145 Rat Liver Metabolism Pathway of 8:2 FTOH yields PFOA and adducts of FT unsaturated aldehydes and acids (Martin et al 2005) Note: important that PFNA (C9) is, at most, a minor component, indicating that oxidation at the a-carbon is slow 00014G Do fluorotelomer based polymers degrade? surface exposure of the polyfluoro chain which gives stain/water repellency is expected to encourage the degradation and release of the polyfluorinated moiety F C F C F C F C F C FC' Degradation of a fluorotelomer based polymer at the urethane linkage was observed in an in vitro study using cholesterol esterase (Jahangir et al. 2003) Degradation of the fluorotelomer based polymer above is predicted to occur at the urethane linkage by various QSAR models e.g. CATABOL, yielding an FTOH 000147 Persistence and bioaccumulation of FTOHs and PFCAs 000148 Bioconcentration factors (BCF) for PFCAs in juvenile rainbow trout increase with Chain Length Additional CF2results in a ~7x increase in the BCF. even:odd pattern expect PFNA higher than PFOA; PFUnA > PFDA, etc IF delivered in similar quantities. 000149 Bioaccumulation of PFCAs in the Lake Ontario Food Web ... suggests benthic sources are important t___________ Lake Trout V Rainbow Smelt Alewife Mysis Slimy Sculpin Diporeia Ln concentration (ng/g wet weight) 3.0 3.5 4.0 4.5 5.0 Trophic Level Martin, JW, DM Whittle, DCG Muir and SA Mabury. 2004. Perfluoroalkyl Contaminants in a Food Web From Lake Ontario. Environ. Sci. Technol. 38:5379-5385. 000150 Atmospheric in of PF acids Bioaccumulation pathways in Lake Ontario Continuous inputs and episodic events e.g. A FFFs S TP and tributary (acids, inputf Dissolved precursors, phase monomers, polymers) Smelt & alewife Mysids Slow elimination by large fish compared to lab fish Direct uptake via gills or unidentified precursors? Sculpin Phytoplankton plankton Sediments appear to be major source Bioavailability in sediments. Precursors, acids, polymers? 000151 Bioaccumulation factors for PFCAs in freshwater and marine fishes based on coinciding fish and water measurements PFA Lake trout (Martin et al. 2004) + water (Furdui et al) Lake trout (Furdui et al. 2006) Various species (Houde et al. 2006) Various species Lab BCF of marine fish (Martin et (Kallenborn et al. 2003) al. 2004) Lake Ontario PFOA 270 4 Great Lakes Charleston Iceland, (C8-C10) & SC harbor Denmark, Lake Ont Swedish Baltic (C11-C12) coast, Faroe Is 1 2 6 0 160 95 180 Based on Lake trout carcass 4 PFNA 4,530 3980 330 560 9,500 - PFDA 13,780 7940 610 1,500 - 450 PFUnA PFDoA 55,300 8,680 10,900 1,560 2,200 >7,700 - 2,700 18,000 000152 PFCA biomagnification factors in freshwater and marine food webs Predator Prey Reference PFOA PFNA PFDA PFUnA PFDoA Lab BMFs > fish/invertebrates Arctic Cod Zooplankton sculpin Diporeia Sea trout pinfish lake trout lake trout (diet weighted) alewife prey 0.038 0.04 0.5 7.2 0.6 0.4 m - 0.6 1.5 5.3 2.3 Mammals - fish Dolphin (whole) Dolphin (whole) Beluga (liver) Polar bear (liver) Pinfish 13 3.2 seatrout 1.8 2.1 Cod 2.7 m Ringed seal (liver) 7.9 14 0.23 0.28 -m 0.9 1.0 3.7 0.9 4.4 6.4 2.7 3.4 8.8 2.4 2.4 2.5 -- 4.5 2.6 0.43 ] m 1.0 0.1 1.9 1.6 Tomy et al 2004 Martin et al 2004 Houde et al. 2006 Martin et al 2004 Martin et al 2004 0.1 0.6 - 0.8 Houde et al. 2006 Houde et al. 2006 Tomy et al. 2004 Martin et al. 2004 p. 20 000153 Toxicology and Human risk assessment Health Canada's hazard evaluation based on the hypothesis of ultimate breakdown of the notified substances and residual materials. These breakdown products will ultimately be PFCAs of various chain lengths - primarily 8 carbons and greater. Most toxicological studies on laboratory animals have been on PFOA (C8) 000154 Toxicology and Human risk assessment PFOA and its salts; produce moderate to high oral toxicity in rodents and monkeys mortality at very low doses in monkeys (20/30 mg kg-1d'1); very narrow range between appearance of toxicity and death cause tumours in rats and immunotoxic effects in mice; display reproductive/developmental effects in rodents Science Advisory Board to the US EPA recommends `likely human carcinogen' classification Longer chain PFCAs; PFCAs (>C8) are reasonably expected to be of greater concern than PFOA as a result of their known slower clearance rates and higher bioaccumulation potential 000155 Toxicology and Human risk assessment Exposure evidence is equivocal on whether PFOA levels in humans are rising, not enough data yet Many perfluoro compounds are being detected in human blood in Canada and other countries found in foodstuffs including beans, apples; household dust particles (in Canada), Biomonitoring data for Canada indicate PFCAs found in breast milk, blood, fetal cord blood 000156 Toxicology and Human risk assessment Uncertainties Areas of uncertainty for human risk assessment of PFCAs include; large elimination/excretion differences between species for example, remarkable differences in clearance rates of PFOA Rodent half- life - hours (sex-related differences too) Monkey half- life - days Human half- life - years Data gaps trends of human body burdens? mechanism of action of PFOA and other PFCAs Understanding the laboratory species differences and relevance to humans Effects on susceptible groups (fetus, infants and elderly) 000157 Acute toxicity of PFCAs to the water flea, Daphnia magna (Macdonald et al. 2006; Boudreau et al. 2004) 10:2 FTCA is ~10,000x more toxic to D. Magna than PFDA. Environmental risk Quotients for 10:2 FTCA >100 assuming water concentration <1 ng/L 000158 4. Trends of PFCAs in the environment: 000159 p. 26 il PFCAs (ng/g wet wt) in Lakes lake trout (whole fish; age Furdui et al. 2006 in prep Individual PFCAs (ng/g wet wt) in Great Lakes lake trout (whole fish; age = 4 yrs); Furdui et al. 2006 in prep Highest concentrations in Lake Erie and Lake Huron PFOA predominates in Michigan Concentrations of C13>C12 in 4 of 5 Huron Superior Carboxylates Telomer acids "00161 PFCA bioaccumulation pathways in the Arctic marine food webs. How do polar bears get exposed to PFCAs? Long range transport in the atmosphere -- ^^^^^nmSam^ ,,"jSVh'. Deposition in snowlrain ** -1 River-Mow atmospheric deposition w o u ld .... iiiiligi^ ^ teliiM under Ice biological melt, Rapid delivery. Long food chains Multiple trophic levels Slow elimination in mammals enterohepatfc recirculation Comparison of recent historical trend of PFOA emissions from all sources from 1999-2006 (Prevedouros et al. 2006) suggests PFCAs should be declining (</1)) Cc o Production of perfluorooctane sulfonyl fluoride (PFOSF) had a DT = -11 yrs (Smithwick et al 2006) which is similar to observed increase of PFOS in seals and polar bears. With the withdrawl of this product post-2000 emissions should be declining sharply. 5000- 4000 -- c<Q/>> 3000- 2 2000 1000 o- - 250if 200 I I150 : _ ___ other emissions APFO Mfg FluoroPolymer Mfg 100 50 0 1999 2000 2001 2002 2003 2004 2006 p. 30 19851989 19901994 1997 2000 2001 2002 000163 Concentration (ng/g ww) PFCAs and PFOS in liver of ringed seals at Arviat NU Increasing trend for PFCAs, decline for PFOS post-1998 (Butt et al. in prep) 198819901992199419961998200 2002200420062008 1988 19901" 2 19941" 6 1998 2 2002 24 2006 28 000164 PFCAs and PFOS in ringed seals from Resolute NU increase for PFCAs, decline post-2000 for PFOS (Butt et al. Fluoros 2006 - updated) 14 12 PFNA 10 8 doubling time = 6.7 yrs 6 10i 8- PFDA doubling time = 7.5 yrs 41 2 0 ! ! 2 0 Concentration (ng/g ww) 12 10 PFUnA 8 - doubling time 6 - = 7.1 yrs... 4 2 0{ f f 19901992199419961998 2000 2002 2004 2006 2008 35 30 PFOS 25 Disappearanpe half-life = 6.5 yrs 201 15 10 5 0 -i------------ r----------- 1------------r 1990199219941996199820002002 2004 2006 2008 Year 000165 Temporal trends of PFCAs in polar bears (Smithwick et al ES&T 2006) Concentration (ng/g wet wt) Doubling time (years) Chemical PFOS PFOA PFNA PFDA PFUA PFDoA PFOS PFOA PFNA PFDA PFUA PFDoA R2 0.35 0.48 0.69 0.72 0.57 0.02 0.66 0.14 0.87 0.72 0.85 0.05 East P <0.001 <0.001 <0.001 <0.001 <0.001 0.405 West <0.001 0.055 <0.001 <0.001 <0.001 0.276 DT 9.85.1 7.32.8 3.60.9 4.21.0 4.11.4 nd 134.0 1414 5.60.9 6.71.7 6.1 1.1 nd p. 33 000166 Trends of Perfluorinated carboxylic acids in polar bear liver (ng/g wet wt) (Smithwick et al. 2005) C8 C9 CIO C ll 11 i i 4 0 0 -I 350- 3001 250- 5 200O) 150O) c 100- 50- 0- p. 34 South Hudson Ba ^South Biiffi Island Smithwick et al. ES&T 2005 000167 PFOA in polar bears mostly `straight' but some (~10%) branched chains; PFNA `straight' only implying FTOH source PFNA A .O . D eS ilv a & SA M abury, 2004. Isolating Isom ers o f PFA C s in Polar Bears. Environ. Sci. Technol. 3 8 :6 5 3 8 -6 5 4 5 . 000168 PFA profiles and temporal trends in Arctic seabird livers Evidence for FTOH related precursors and for long chain PFCAs (Braune, Butt, et al 2005) 0 <?oVVVVVV' 000169 Uncertainties in overall assessment of fluorotelomer polymers Biodegradation rates of the polymers Rate of degradation and actual release of F TO H s from polymers has not been demonstrated Environmental levels: Contribution of C10-C13 P FC A s from non-fluorotelomer materials (e.g. see Prevedouros et al. 2006) Very limited air measurements of FTO H s Limited measurements of F T O H s in wildlife - only as acids Limited measurements of C14 P FCA s (and up) - these should be solely from fluoro telomers Bioaccumulation C14 P FC A s (and up) could be very P but not B Toxicology remarkable differences in clearance rates among species Understanding the laboratory species differences and relevance to humans 000170 Conclusions Fluorotelomer-based polymers are expected to release F TO H s Into the environment as residual alcohol or through degradation of the polymer; Biodegradation and metabolism studies demonstrate production of persistent PFCAs FTO H s are volatile and have long predicted atmospheric half-lives They can undergo long-range transport Strong evidence exists for their transformation to P FC A s via OH-radical reaction The properties of longer carbon-fluorine chain length P FC A s (QD9) include high persistence, bioaccumulation (lab and field data) Adverse effects of P FO A in laboratory mice, rats and monkeys; including high subchronic oral toxicity, tumorigenicity, and immunological toxicity. PFCA s (>C8) are reasonably expected to be of greater concern than P FO A as a result of their known slower clearance rates and higher bioaccumulation potential PFCAs are widespread throughout Arctic and Great Lakes biota and evidence indicates that concentrations in wildlife tissues are increasing over time 000171