PBDEs

1
PBDEs an emerging environmental concern

• Suzanne M. Snedeker, Ph.D.
• Biomonitoring II
• Mini-Talk 2b
• February 3, 2006
• EnviroCancer Connections
• Long Distance Learning

A special thanks to Ellen Hartman and Kasia
Fertala for their help in compiling data and
graphic images.
2
Polybrominated biphenyl ether (PBDEs) flame
retardants
Bromine can be placed at any x
X
X
X
X
X
X
X
X
X
X
Phenol ring
Phenol ring
Ether Bridge
Tri-3 Tetra-4 Penta-5 Hexa-6 Hepta-7 Octa-8
Nona-9 Deca-10
3
What products are PBDEs used in? -three
commercial mixes

• Penta
• Furniture, mattress, auto, and office chair
  upholstery polyethylene foams
• Solid foams used in electrical appliances
• Octa
• ABS hard plastic in computer monitors and TV
  housings, circuit boards
• Deca
• High impact polystyrene plastic housing for
  computers, TVs, and other electronic appliances
• Polyethylene in wires, cables and pipes
• Textile coatings and backings for upholstery and
  drapes

4
PBDEs Why is there an emerging concern?

• Widespread use since 1980
• Rising levels in humans (esp. in U.S.)
• Breast milk, fat, blood
• Detection in wildlife globally
• Persistency
• Health effects identified in cell culture studies
  and animal models
• Few studies on human health effects

5
PBDEsWho. What. Where. When.
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PBDEs in human breast milk

• Breast milk levels in Sweden increased from
  negligible levels in 1972 to 4.02 ng/g by 1997
• Breast milk levels started to drop by 1999 after
  regulatory action in Sweden
• In U.S. PBDE breast milk levels are over 10 - 30
  fold higher than in Europe

7
PBDE levels in human breast milk (Europe and
the U.S.)
Sum of PBDEs in human breast milk (ng/g lipid)
1997
2000
2000-03
1999
2002
Year of analysis
8
Trends in PBDE blood levels (Norway,
Japan, and the U.S.)
Sum of PBDEs in human blood (ng/g lipid)

• 1999
• Norway (Thomsen)

1980 1995 Japan (Koizumi)
1973 2003 U.S. (Schecter)
Dates of analysis and country (author)
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PBDE levels in human fat samples (Europe and
U.S.)
Location First Author (Year)
Belgium Covaci (2002)
San Francisco, CA She (2002)
New York City, NY Johnson-Restrepo (2005)
Sum of PBDEs in human fat tissue (ng/g fat)
10
PBDEs in wildlife -Detected globally

• Great Lake fish - rapid rise
• Raptors, sea birds, bird eggs
• (Europe, Japan, and U.S.)
• Arctic mammals
• San Francisco Bay harbor seals

11
Trends in contaminants (1984-1999) in Lake
Michigan fish (smelts)
PBDE-47
PCBs
1984
1984
1999
1999
Halving every 8 yrs
Doubling every 1.75 yrs
Ref Chernyak, Enviro. Tox. Chem.,241632-41,
2005.
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Potential health hazards

• Structurally similar to PCBs
• Evidence of hormone disruption
• Some estrogenic (PBDE 100)
• Some disrupt thyroid hormone pathways
• Animal studies (at high doses of PBDEs)
• Liver and pancreatic tumors - Deca
• Hyperactivity, increases with age
• Effects on sperm formation
• Skeletal malformations

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How can humans be exposed? - We dont
exactly know

• Food chain (?)
• Polyurethane foam degrades in landfill
• Eaten by insects -gt birds
• Leach from landfills / sludge -gt waterways
• Eaten by fish -gt birds
• Detected in livestock fat

14
How can humans be exposed? - We dont
exactly know

• Breathing dust from foam / plastic (?)
• Detected in dust on computer housings
• Detected in dryer lint, house /vacuum dust
• Workers exposed in electronic recycling sites

15
Unresolved issues -Can Deca form be degraded?

• Early studies, not stored in tissues
• Recent studies, detected in wildlife
• Some fish can debrominate Deca
• Lower debrominated forms of PBDEs can be absorbed
• Deca photolytically degradable in the lab no
  data on whether degradable by sunlight in the
  field