Polybrominated biphenyls, contamination

Anderson HA, Wolff MS, Lilis R, et al. 1979. Symptoms and clinical abnormalities following ingestion of polybrominated-biphenyl-contaminated food products. Arm N Y Acad Sci 320 684-702. 

BarrM. 1980. Pediatric aspects of the Michigan polybrominated biphenyl contamination. Environ Res 21 255-274. 

Fries GF, Jacobs IW. 1980. Residual polybrominated biphenyl contamination Locations, amounts and significance on dairy farms. J Dairy Sci 63 114. 

Jackson TF, Halbert FL. 1974. A toxic syndrome associated with the feeding of polybrominated biphenyl-contaminated protein concentrate to dairy cattle. J Am Vet Med Assoc 165 437-439. 

Associated with the Feeding of Polybrominated Biphenyl-contaminated Protein Concentrate to Dairy Cattle," J. Amer. Veterinary Med. Assoc. 165(5). 437-442 (1974). 

The principal source of pollution by polybrominated biphenyls (PBBs) has been the commercial mixture Firemaster, which was produced in the United States between 1970 and 1974. Production was discontinued in 1974 following a severe pollution incident in Michigan, when Firemaster was accidentally mixed with cattle feed on a farm. In due course, PBBs entered the human food chain via contaminated animal products. Substantial residues were found in humans from the area, and were snbse-quently found to be highly persistent. 

Pijnenburg, A., Everts, J., and de Boer, J. et al. (1995). Polybrominated biphenyl and diphe-nylether flame retardants analysis, toxicity, and environmental occurrence. Reviews in Environmental Contamination and Toxicology. 141, 1-26. 

The dehalogenation of polychlorinated or polybrominated biphenyls was more rapid in cultures using inocula prepared from sediments contaminated with the chlorinated or bro-minated biphenyl, respectively (Morris et al. 1992). 

Mixed cultures of organisms that were isolated from sediments contaminated with PCBs and polybrominated biphenyls (PBBs) were shown to debrominate PBBs under anaerobic conditions (Morris et al. 1992), and the dominant congener—2,2, 4,4, 5,5 (245-245)-hexabromobiphenyl—could be successively debrominated to 2,2 -dibromobiphenyl. However, in sediments from the most heavily contaminated site containing contaminants in addition to PBBs, very little debromination occurred and the recalcitrance was attributed to the toxicity of the other contaminants (Morris et al. 1993). 

The structural range of industrially important representatives of these groups is enormous, and includes chlorobenzenes (solvents), polychlorinated biphenyls (PCBs) (hydraulic and insulating fluids), and polybrominated biphenyls and diphenyl ethers (flame retardants). There is widespread concern over both the persistence and the potential toxicity of all these compounds, and sites that have become contaminated during their production represent a threat both to the environment and to human health. Pathways for the aerobic bacterial degradation of chlorobenzenes and chlorobiphe-nyls, and their brominated analogs have been discussed in Chapter 9, Part 1. 

Pijnenburg AMCM, Everts JW.de Boer J, Boon JP (1995) Polybrominated biphenyl and diphenyl ether flame retardants analysis, toxicity, and environmental occurrence. In Ware GW (ed) Reviews of environmental contamination and toxicology, vol 141. Springer, Berlin Heidelberg New York, p 2... 

Polybrominated biphenyls (PBBs) Contaminant Fire retardant inadvertently substituted for feed supplement in Michigan livestock loss, undetermined effect on human health... 

Polybrominated Biphenyls. Symptoms of musculoskeletal effects, described as "joint pain" and "swelling in joints," were frequently cited health complaints in two epidemiological studies of groups of Michigan residents who were likely to have ingested PBB-contaminated food (Anderson et al. 1978c Landrigan et al. 

Polybrominated Biphenyls. No statistically significant correlations were found between serum PBB levels and serum levels of blood urea nitrogen (BUN) or creatinine in a study of residents of quarantined Michigan farms after the 1973 PBB contamination episode (Kreiss et al. 1982). No other studies were located with information pertinent to renal effects in humans after oral exposure to PBBs. 

Polybrominated Biphenyls. Numerous reports have been published regarding the immunological competence of individuals exposed to PBBs in the Michigan feed contamination episode. Due to the relatively high number of published reports and to the fact that often different groups of investigators appear to have examined the same cohort, only representative studies are discussed below. 

Polybrominated Biphenyls. Analysis of semen from 41 male residents of Michigan who lived on PBB-contaminated farms or who had bought food directly from such farms and 11 males who were employed in a PBB manufacturing company revealed no abnonnalities in tlie distribution of sperm counts, spenn motility, or sperm morphology, compared w ith an analysis of semen from 52 unexposed men (Rosenman et al. 1979). Tills study was conducted in 1977, 4 years after initial contamination of Michigan s food supply, and would not have detected an earlier response that was subsequently reversed. PBBs were detected (detection limit of 0.2 ppb) in tlie serum of 1 of the 52 unexposed men and in all of the exposed men however, individual or mean values for PBB levels were not reported. 

Polybrominated Biphenyls. Examination of children ( 100 were identified) presumably exposed in utero or in early infancy during the peak of the Michigan PBB contamination episode and whose families lived on farms known to be contaminated with PBBs has not revealed any consistent or maiked abnormalities in the children s physical and neuropsychological development. No significant abnormalities were found by physical and neurological examination of 33 of these exposed children when they had a mean age of... 

Polybrominated Biphenyls. Quantitative oral absorption data in humans were not located, but reports of increased levels of PBB residues in tissues and serum of individuals accidentally exposed to contaminated food indicate that gastrointestinal absorption of PBBs had occurred (Eyster et al. 1983 Humphrey and Hayner 1975 Landrigan et al. 1979 Miceli et al. 1985 Wolff et al. 1982). 

Polybrominated Biphenyls. The mechanism by which PBBs enter the blood stream from the lungs, skin, or gastrointestinal tract is not known and little information is available on how PBBs are distributed in the body. The available data indicate that the absorption mechanism is likely passive diffusion. Results from studies of Michigan subjects showed that in the blood stream, 80% of the PBBs was bound to protein and 20% was associated with lipids (Greaves et al. 1984). Of the fraction bound to protein, 73% was bound to apolipoprotein B and the remaining percent was bound to apolipoprotein A. In an in vitro model, shown to be representative of environmentally contaminated blood, the distribution of PBBs among plasma, erythrocytes, mononucleocytes, and polymorphonucleocytes was 89 9 <1 <1, respectively (Roboz et al. 1985). 

Polybrominated Biphenyls. A limited amount of information is available regarding reproductive effects in humans after exposure to PBBs. No evidence for PBBs-related effects on sperm counts, motility, or sperm morphology was found in a group of male Michigan workers exposed to PBBs by inhalation or dermal contact (Rosenman et al. 1979). No relationship was found between serum levels of PBBs and the frequency and duration of lactation in women exposed during the Michigan contamination episode (Thomas etal. 2001). 

Polybrominated Biphenyls. The production of PBBs in the United States ceased in 1979 (lARC 1986). In the past, PBBs were released to the environment during the manufacture of these compounds and disposal of commercial and consumer products containing these compounds (Hesse and Powers 1978 Neufeld et al. 1977). One of the significant sources of environmental contamination occurred as a result of the accidental mixup ofFireMaster BP-6 with cattle food in a number of farms in the lower peninsula in Michigan (see Section 3.2 for additional details concerning this incident). By June 1975, 412 farms had been quarantined. Disposal of contaminated feed, animal carcasses (poultry, cattle, swine), and... 

Polybrominated Biphenyls. The important former sources of PBBs in soil are manufacturing operations, disposal of PBB-containing finished products, and agricultural operations contaminated in the original episode in 1973 1974. The concentrations of PBBs in soils from bagging and loading areas of the Michigan Chemical Corporation were 3,500 and 2,500 mg/kg, respectively (Di Carlo et al. 1978). 

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