Download - Polybromated Biphenols
Polybromated Biphenols
Andrea LeasureBIOL 464
Structure of the Compound
Physical & Chemical Properties
Colorless to off-white solidsLow vapor pressureSoluble in fat, organic solvents (solubility
decreases w/ increasing bromine number) Insoluble in waterRelatively stable & chemically unreactive
Photodegrade upon exposure to UV light
Uses & Applications
Uses & Applications
• Flame retardant additives in synthetic fibers & molded plastics.
• Added to plastics to make them difficult to burn• Ex: Home electrical appliances, textiles, plastic foams.
• Flame retardant additives in synthetic fibers & molded plastics.
• Added to plastics to make them difficult to burn• Ex: Home electrical appliances, textiles, plastic foams.
Production History
No longer produced in the United States (1976)
PBBs are still around in the environment because they do not degrade easily or quickly
Formerly produced in 3 primary forms:– Hexabromobiphenyl – Octabromobiphenyl– Decabromobiphenyl
Production History
In 1973, several thousand pounds of hexabromobiphenyl were accidentally mixed with livestock feed in Michigan– 1.5 million chickens– 30,000 cattle– 5,900 pigs– 1,470 sheep
Bitter Harvest, 1981 film
Mode of Entry in Aquatic Environment
Mode of Entry in Aquatic Environment
PBBs entered the air, water & soil from poorly maintained hazardous waste sitesImproper incineration of plastics containing PBBs.
Lower brominated PBBs are widely spread in the environment & bioaccumulate in aquatic biota
Higher brominated PBBs primarily bind to sediment & will hardly spread in aquatic systems or accumulate in biota.
PBBs entered the air, water & soil from poorly maintained hazardous waste sitesImproper incineration of plastics containing PBBs.
Lower brominated PBBs are widely spread in the environment & bioaccumulate in aquatic biota
Higher brominated PBBs primarily bind to sediment & will hardly spread in aquatic systems or accumulate in biota.
Chemical Reactivity
• 209 congeners (congener pattern found in fish samples is different from that in commercial products)
• 3,3',4,4',5,5'-hexaBB (BB-169) was found to be the most toxic PBB
• Half-life in humans 7.8-12 years
Toxicity to Aquatic Life• Exposed PBB water birds, nesting on islands in Lake
Michigan, had no effect on reproduction.
• Zebra mussels (Dreissena polymorpha)– Concentrations ranged from 0.85 to 22.44
(ng/g ww) with no effect
• Freshwater Tilapia (Oreochromis niloticus ) – 6 h EC50 6.6 × 10−6 M
– 24 h EC50 7.3 × 10−6 M
Toxicity Effects
Reduction of feed consumption (decrease in body weight)
Causes skin disorders, nervous and immune systems effects, and effects on the liver, kidneys, and thyroid gland
Changes in the metabolism of vitamin A (retinol compounds and retinoic acid), which is important for cellular growth and differentiation
Mode of Entry into Organisms
Mode of Entry into Organisms
• Gills• Ingestion • Breast milk
• Gills• Ingestion • Breast milk
Molecular Mode of Toxic InteractionMolecular Mode of Toxic Interaction
Induces CYTP450
Induction of metabolic enzymes of hepatic
microsome (arylhydrocarbon hydroxylase)
Interaction w/AHH receptors cause
alteration in the expression in a number
of genes.
Induces CYTP450
Induction of metabolic enzymes of hepatic
microsome (arylhydrocarbon hydroxylase)
Interaction w/AHH receptors cause
alteration in the expression in a number
of genes.
Biochemical Metabolism
Higher brominated PBBs are
metabolized at a much slower rate
than the lower brominated isomers.
The most frequently reported route
of PBB metabolism was hydroxylation
aryl hydrocarbon hydroxylase (AHH
system)
Defense StrategiesDefense Strategies
• Excretion through feces
• Excretion through breast milk
• Treatment to increase
elimination of PBB in animals or
humans was usually unsuccessful
• Excretion through feces
• Excretion through breast milk
• Treatment to increase
elimination of PBB in animals or
humans was usually unsuccessful
BibliographyBibliography Primary cultured cells as sensitive in vitro model for assessment of
toxicants- compasion to heptocytes and gill epithelia. Aquatic Toxicology, Volume 80, Issue 2, 16 November 2006, Pages 109-118 Bingsheng Zhou, Chunsheng Liu, Jingxian Wang, Paul K.S. Lam, Rudolf S.S. Wu
Microcontaminant accumulatoin, physiological condition and bilateral asymmetry in zebra mussels (Dreissena polymorpha) from clean and contaminated surface waters. Aquatic Toxicology, Volume 79, Issue 3, 12 September 2006, Pages 213-225 Judith Voets, Willem Talloen, Tineke de Tender, Stefan van Dongen, Adrian Covaci, Ronny Blust, Lieven Bervoets
http://www.inchem.org/documents/hsg/hsg/hsg083.htm Accessed April 17,2008
http://ntp.niehs.nih.gov/ntp/roc/eleventh/profiles/s148pbb.pdf Accessed April 17, 2008
http://www.atsdr.cdc.gov/tfacts68.html Accessed April 17, 2008
http://www.michigan.gov/documents/mdch_PBB_FAQ_92051_7.pdf Accessed April 28, 2008
http://www.ehponline.org/docs/1978/023/toc.html Accessed April 28, 2008
http://www.meti.go.jp/english/report/downloadfiles/gED0306e.pdf Accessed April 30, 2008
Primary cultured cells as sensitive in vitro model for assessment of toxicants- compasion to heptocytes and gill epithelia. Aquatic Toxicology, Volume 80, Issue 2, 16 November 2006, Pages 109-118 Bingsheng Zhou, Chunsheng Liu, Jingxian Wang, Paul K.S. Lam, Rudolf S.S. Wu
Microcontaminant accumulatoin, physiological condition and bilateral asymmetry in zebra mussels (Dreissena polymorpha) from clean and contaminated surface waters. Aquatic Toxicology, Volume 79, Issue 3, 12 September 2006, Pages 213-225 Judith Voets, Willem Talloen, Tineke de Tender, Stefan van Dongen, Adrian Covaci, Ronny Blust, Lieven Bervoets
http://www.inchem.org/documents/hsg/hsg/hsg083.htm Accessed April 17,2008
http://ntp.niehs.nih.gov/ntp/roc/eleventh/profiles/s148pbb.pdf Accessed April 17, 2008
http://www.atsdr.cdc.gov/tfacts68.html Accessed April 17, 2008
http://www.michigan.gov/documents/mdch_PBB_FAQ_92051_7.pdf Accessed April 28, 2008
http://www.ehponline.org/docs/1978/023/toc.html Accessed April 28, 2008
http://www.meti.go.jp/english/report/downloadfiles/gED0306e.pdf Accessed April 30, 2008