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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)
Plastic materials that contain PBDEs– 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)
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
PBDE Technical Mixture
Million lbs/yr (2001)
% of World’s
UseProduct Uses
Penta-BDE†
15.7 95 Furniture (foam cushions)
Octa-BDE 3.3 40 Electronics (ABS plastic, cable)
Deca-BDE 54.0 44 Electronics (HIPS plastic) and textiles
† 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
O
O
I
I
I
I
OH
NH2
OH
Br
Br Br
Br Br
O
Thyroxine (T4)
2,2',4,4',6-pentabromodiphenylether (PBDE-100)
4-(2',4',6'-tribromophenoxy)-2,6-dibromophenol (hydroxy-PBDE)
2-(2',4'-dibromophenoxy)-4,6-dibromoanisol (methoxy-PBDE)
CH3
BrO
O
Br Br Br
Br
Br
O
Br
Br
Br
OH
Cl
Cl
Cl
Cl
Cl
Cl
2,2',4,4',5,5'-hexachlorobiphenyl (PCB-153)
Br
O
Br
BrBr
Br
2,3,4,7,8-pentabromodibenzofuran (PBDF)
PBDE concentrations on the rise… Organohalogen Compounds in Human Milk in Sweden
(Norén and Mieronyté, 1998)
C o m p a r i s o n B e t w e e n C o n c e n t r a t i o n s o f P B D E s i n B r e a s t M i l k f r o m N o r t h A m e r i c a a n d E u r o p e
S a m p l i n g Y e a r
1 9 7 5 1 9 8 0 1 9 8 5 1 9 9 0 1 9 9 5 2 0 0 0
Co
ncn
etra
tio
n (n
g/g
lip
id w
eig
ht)
0
5 0
1 0 0
1 5 0
2 0 0N o r t h A m e r i c aS w e d e nF i n l a n d
S a m p l e s c o l l e c t e d i n A u s t i n & D e n v e r
S a m p l e s c o l l e c t e d i n N e w Y o r k S t a t e
C a n a d i a n M i l k B a n k
C a n a d i a n M i l k B a n k
4
C a n a d i a n M i l k B a n k a n d N e w Y o r k S t a t e f r o m R y a n a n d P a t r y 2 0 0 0 , D e n v e r a n d A u s t i n r e s u l t s f r o m P a p k e e t a l
2 0 0 1 ; S w e d i s h d a t a f r o m M e i r o n y t e G u v e r n i u s a n d N o r e n 2 0 0 1 , F i n n i s h d a t a f r o m S t r a n d m a n e t a l . 2 0 0 0
Figure courtesy of Dr. John Ryan of Health Canada and Dr. Mehran Alaee of Environment Canada:
Time-trend: PBDEs in Blubber of California Seals
0100020003000400050006000700080009000
01/01
/89
01/01
/91
12/31
/92
12/31
/94
12/30
/96
12/30
/98
PB
DE
(ng
/g li
pid)
N=11 (She et al., 2002)
PBDEs in Columbia River Whitefish
0
10
20
30
40
50
60
70
80
1992 1995 2000
Sum PBDE (ng/gfresh weight)
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 CyclePenta-BDE Deca-BDE
Consumer productsPolybrominated Dioxins and Furans
Air/ Dust Waste
Food (penta)
(Urban runoff; Sewage sludge;E-waste)
Biota (fish)
Hydroxy-PBDEsMethoxy-PBDEs
Cross- media issue
(Indoor/ outdoor)
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)
Influent (~ 50 lbs/year)
Stack emissions (PBDF /PBDD) <6.1 x 10-7 lbs/yr
Effluent 2 lbs/yr
Sludge 48 lbs/yr
Incinerator
Ash(not analyzed)
Penta Formulation
Accounts for >90 % of the PBDEs in most humans. However, minor congeners may be important.
Br
Br Br
Br Br
O
2,2',4,4',6-pentaBDE (PBDE-100)
2,2',4,4'-tetraBDE (PBDE-47)
2,2',4,4',5-pentaBDE (PBDE-99)
2,2',4,4',5',5-hexaBDE (PBDE-153)
2,2',4,4',5,6'-hexaBDE (PBDE-154)
Br Br
Br Br
Br Br
O
Br
Br Br
Br Br
O
Br
Br
Br Br
Br Br
O
Br
Br Br
Br
O
Mass of PBDEs in Effluent and Biosolids
11
13
2
1 1
17
0.73 0.780.14 0.07 0.05 0.12
02468
1012141618
BDE-47 BDE-99 BDE-100
BDE-153
BDE-154
BDE-209
lbs/
year
Biosolid Effluent
Penta-Formulation Deca-BDE
Comparison of Sludge Results (ug/kg dry weight)
SourcePenta
Formulation*Deca- BDE
City of Palo Alto 1,918-2,086 1,010-1,440
Hale’s study (Throughout U.S.)
1,100-2,290 85-4,890
European Studies 0.4-239 140-350
*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/