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Learn about Polybrominated Diphenyl Ethers (PBDEs), including why they are a cause for concern, their commercial uses, and their impact on the environment. Explore Palo Alto's sampling results and the potential sources of PBDE contamination.
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PBDEs: Will Our Sludge Burn Karin Didriksen North City of Palo Alto 650-494-7629 Karin.North@cityofpaloalto.org
Polybrominated Diphenyl Ethers • What are PBDEs? • Why are we concerned? • Palo Alto’s sampling results
Polybrominated Diphenyl Ethers • 209 congeners • 1 to 10 bromines • Mono smallest congener • Deca largest congener • Similar to PCBs and Dioxins in regards to number of congeners
Background • Added to many consumer products • Chemical fire retardant • Saves lives • On the Regional Board’s “watch list”
Commercial Uses • High-impact plastic; other plastics, rubbers and resins • 1 to 10 % by weight of TV and computer casings • Polyurethane foam (30% by weight) (furniture) • Textile coatings (drapes, carpet backings)
ABS polyacrylonitrile (PAN) polyamide (PA) polybutylene terephthalate (PBT) polyethylene (PE) polyvinyl chloride (PVC) polyurethane (PUR) (foam) unsaturated polyester (UPE). cross-linked polyethylene (XPE) polyethylene terephthalate (PET) polypropylene (PP) polystyrene (PS) high-impact polystyrene (HIPS) Plastic materials that contain PBDEs
Commercial Mixtures of PBDEs • Penta-BDE (used in foam) • Polyurethane foam in seat cushions and carpet padding • Printed circuit boards • All congeners highly bioaccumulative • 86 to 99% of congeners found in human tissues
Commercial Mixtures of PBDEs (cont) • Octa-BDE (used in plastics, textiles) • Electrical connectors • Automotive interior parts • Deca-BDE (plastics, textiles) • Computer cases • Carpet backing and textiles
PBDE Use in the Americas †Highly bioaccumulative BSEF, 2003
Environmental Concerns • Endocrine Disruption • Persistent Organic Pollutants (POP)/ Persistent Bioaccumulative Toxicants (PBT) • Structurally similar to PCBs and DDT • Lower brominated congeners bioaccumulate • Emerging Environmental Challenge • High Production Volume (HPV) Chemical
Structural Similarity of PBDEs, Their Metabolites and Environmental Derivatives to T4 and PCBs
PBDE concentrations on the rise… Organohalogen Compounds in Human Milk in Sweden (Norén and Mieronyté, 1998)
Figure courtesy of Dr. John Ryan of Health Canada and Dr. Mehran Alaee of Environment Canada:
Time-trend: PBDEs in Blubber of California Seals N=11 (She et al., 2002)
PBDEs in Columbia River Whitefish From Genelle, British Columbia Rayne et al. (2003) Environ Sci Technol 37(13):2847-54.
PBDEs Have Become Ubiquitous Environment Contaminants PBDEs are measured in • Indoor and outdoor air • Remote Arctic regions (i.e., long-range transport) • House and office dust • Rivers and lakes and sediments • Sewage sludge • Foods • Biota (terrestrial and marine mammals, fish, humans)
PBDE Life Cycle Deca-BDE Penta-BDE Cross- media issue Consumer products Polybrominated Dioxins and Furans (Indoor/ outdoor) Air/ Dust Waste (Urban runoff; Sewage sludge;E-waste) Biota (fish) Food (penta) Hydroxy-PBDEsMethoxy-PBDEs
Palo Alto’s Study • August 2002 • 3 days of sampling, composite samples • Effluent and biosolids tested for 41 PBDE congeners • Incinerator emissions tested for brominated furans and brominated dioxins • Concentration levels at ppt (ng/L or ng/kg)
Palo Alto’s Loading Data • 96% of PBDEs sorb onto biosolids • 4% of PBDEs are discharged to Bay • Incinerator transforms PBDEs to brominated furans and brominated dioxins • Air pollution control device destroys 99.9% of dioxins and furans
Fate of PBDEs(wastewater treatment plant) Stack emissions (PBDF /PBDD) <6.1 x 10-7 lbs/yr wastewater treatment Sludge 48 lbs/yr Influent (~ 50 lbs/year) Incinerator Ash(not analyzed) Effluent 2 lbs/yr
Penta Formulation Br Br Br Br Br Br O O O Br Br Br Br Br Br Br Br 2,2',4,4',6-pentaBDE 2,2',4,4'-tetraBDE 2,2',4,4',5-pentaBDE (PBDE-100) (PBDE-47) (PBDE-99) Br Br Br Br O O Br Br Br Br Br Br Br Br 2,2',4,4',5',5-hexaBDE 2,2',4,4',5,6'-hexaBDE (PBDE-153) (PBDE-154) Accounts for >90 % of the PBDEs in most humans. However, minor congeners may be important.
Mass of PBDEs in Effluent and Biosolids Penta-Formulation Deca-BDE
Comparison of Sludge Results (ug/kg dry weight) *sum of “penta-like” congeners
Correlation of PBDF with PBDE in German Sewage Sludge Used on Crops Hagenmaier et al. (1992) Chemosphere 25:1457-62 • . PBDE levels in U.S. sludge are 10- to 100-fold higher than European samples(Hale et al., 2001 Nature 412:140-1).
Overview of Results • PBDE concentration in US Sludge is 10 to 100x greater than Europe • Deca-BDE largest concentration in biosolids (~1,183 ppb) • Renewed concern over Deca (new data on debromination by UV and biota) • BDE-99 (part of penta-formulation) largest concentration in effluent (~0.01 ppb)
Potential Sources to POTW • Unclear direct source since it is found everywhere in the environment • Some possible sources include: • Rinsing of cleaning rags • Carpet cleaning • Laundry and shower gray water • Human waste
Penta and Octa-BDE are now Banned • Banned in California starting 2008 • AB302 (Chan et al.) signed into law August, 2002 • US manufacturer announced it will voluntarily cease production by end of 2004 • Banned in European Union starting 2005 • Already voluntarily phased out in Japan
Text of California Ban (AB302) “ On and after January 1, 2008, a person may not manufacture, process, or distribute in commerce a product, or a flame-retarded part of a product, containing more than one-tenth of 1 percent of pentaBDE or octaBDE, by mass.”
Summary • 96% of PBDEs that enter the plant end up in the sludge • High concentration of PBDEs in sewage sludge • US PBDE sludge concentrations 10 to 100x greater than Europe • Unclear if 2 lbs/year is a significant contribution to the Bay
General Summary • PBDEs in consumer products are escaping into the environment – now everywhere • PBDE levels rising rapidly in fish, other wildlife and people in North America • Penta- and Octa-PBDE banned in CA and the EU; not used in Japan.
Key Sources for PBDEs • “Tracking the Fate of Polybrominated Diphenyl Ethers (PBDEs) at the Regional Water Quality Control Plant, Palo Alto, Ca http://www.city.palo-alto.ca.us/cleanbay/pdf/PBDE04.pdf • Brominated Flame Retardants Information Clearinghouse funded by CalEPA http://www.greenstart.org/efc9/