Polybrominated biphenyls PBBs

The chemical is banned. PBBs may not be used for the production of textile articles (clothes, underwear, bedclothes, etc.) to come into contact with human skin. All other uses than the use in textile articles intended to come in contact with the skin are continued. PBBs cause weight loss, liver damage, porphyria, effects on the central nervous system, skin, eyes and the immune system, effects on reproduction, they are weakly teratogenic (embryotoxic) in cattle and laboratory animals. 

IPCS HEALTH AND SAFETY GUIDE, 83, 1993 IPCS ENVIRONMENTAL HEALTH CRITERIA, 152, 1994 

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Except for polybrominated biphenyls (PBB), a limited number of studies regarding the toxicity of aromatic brominated compounds has been performed. Some experiments suggest a moderate acute toxicity of these compounds (ref. 1). 

The polychlorinated biphenyls (PCBs) and polybrominated biphenyls (PBBs) are indnstrial chemicals that do not occur naturally in the environment. The properties, uses, and toxicology of the PCBs are described in detail in Safe (1984), Robertson and Hansen (2001), and Environmental Health Criteria 140. PBBs are described in Safe (1984) and Environmental Health Criteria 152. 

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. 

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 challenge was to avoid the use of hazardous brominated fire retardants such as polybrominated biphenyl (PBB) and pentabromodiphenyl ether (PBDE). The first strategy was to replace PBB and PBDE with tetrabromo-bisphenol-A (TBBA). This has a much lower toxicity, but is still a brominated fire retardant with safety concerns. An improvement... 

For this purpose, the WEEE Directive has been complemented with an additional directive that limits the use of certain pollutants in these products. The EC Directive 2002/95/EC on the Restriction of the use of certain Hazardous Substances in electrical and electronic equipment (RoHS Directive) ([7], recast 2011 [9]) restricts the use of the six harmful substances/substance families lead, mercury, hexavalent chromium, polybrominated biphenyls (PBB), and polybrominated diphenyl ethers (PBDE) to 0.1% and cadmium to 0.01% w/w per homogenous material in equipment and components, but with several exemptions for a wide range of applications (Annex III and IV). 

Table 1 Concentrations of chlorinated polycyclic aromatic hydrocarbons (CIPAHs), polybrominated diphenyl ethers (PBDEs), polychlorinated biphenyls (PCBs), polybrominated biphenyls (PBBs), polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), and polybrominated dibenzo-p-dioxins and dibenzofurans (PBDD/Fs) in ambient air, soil, and human samples collected from e-waste recycling and reference sites in China... 

BFRs are one of the last classes of halogenated compounds that are still being produced worldwide and used in high quantities in many applications. In order to meet fire safety regulations, flame retardants (FRs) are applied to combustible materials such as polymers, plastics, wood, paper, and textiles. Approximately 25% of all FRs contain bromine as the active ingredient. More than 80 different aliphatic, cyclo-aliphatic, aromatic, and polymeric compounds are used as BFRs. BFRs, such as polybrominated biphenyls (PBBs), polybrominated diphenyl ethers (PBDEs), hexabromocyclododecane (HBCD), and tetrabromobisphenol A (TBBPA), have been used in different consumer products in large quantities, and consequently they were detected in the environment, biota, and even in human samples [26, 27]. 

Stratton CL, Mousa JJ, Bursey JT (1979) Analysis for polybrominated biphenyls (PBBs) in environmental samples, US EPA, report no 560/13-79-001... 

Safe, S. 1984. Polychlorinated biphenyls (PCBs) and polybrominated biphenyls (PBBs) biochemistry, toxicology, and mechanism of action. Crit. Rev. Toxicol. 13 319-393. 

Fig. 7 Generic chemical structures of polyhalogenated compounds. X=C1, Br. (I) Polychlorinated biphenyls (PCBs), polybrominated biphenyls (PBBs) (II) chlorophenols (CPs), bromophenols (BPs) (III) polychlorinated diphenyl ethers (PCDE), polybrominated diphenyl ethers (PBDE) (IV) polychlorinated dibenzo-p-dioxin (PCDD), polybrominated dibenzo-p-dioxin (PBDD) (V) polychlorinated dibenzofuran (PCDF), polybrominated dibenzofuran (PBDF) (VI) tetrabromobisphenol A (TBBPA)...

Uses. Polybrominated biphenyls (PBBs) are compounds that were formerly used as flame retardants in electrical products and in business machines and motor housings. There are 209 possible bromobiphenyl congeners, although only a small number have been synthesized and used. All of the commercial products contained a mixmre of several individual PBBs. Commercial production ceased in 1977. 

Therefore, in spite of remarkably increased liver injury, the animals are able to overcome injury and survive the potentiated liver toxicity (Kodavanti et al. 1992 Mehendale 1990, 1991, 1992). DDT increased the sensitivity of rats to carbon tetrachloride poisoning (McLean and McLean 1966), and mice fed 100 ppm polybrominated biphenyls (PBBs) or 200 ppm polychlorinated biphenyls (RGBs) in their diet for 28 days experienced increased carbon tetrachloride hepatotoxicity (Kluwe et al. 1979). Potentiation of renal dysfunction was also found in the PBB-pretreated mice. All of these compounds are broad-spectrum MFO inducers. 

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

This public health statement tells you about polybrominated biphenyls (PBBs) and polybrominated dephenyl ethers (PBDEs) and the effects of exposure. 

The primary purpose of this chapter is to provide public health officials, physicians, toxicologists, and other interested individuals and groups with an overall perspective on the toxicology of polybrominated biphenyls (PBBs) and polybrominated diphenyl ethers (PBDEs). It contains descriptions and evaluations of toxicological studies and epidemiological investigations and provides conclusions, where possible, on the relevance of toxicity and toxicokinetic data to public health. 

Polybrominated Biphenyls. PBBs have the potential to interact with the endocrine system based on effects that mainly include changes in levels of thyroid and female reproductive hormones. No studies were located that investigated the estrogenic and antiestrogenic activity of PBBs in vitro or in vivo at the level of the estrogen receptor. 

Polybrominated Biphenyls. PBBs are stored primarily in adipose tissue and are present in serum and human milk of exposed populations. Several studies have shown that serum and adipose PBB levels are biomarkers of exposure (Brilliant et al. 1978 Humphrey and Hayner 1975 Lambert et al. 1990 Landrigan et al. 1979 Michels Blanck et al. 2000b Rosen et al. 1995 Wolff et al. 1982). It has been proposed that measurement of PBB levels in adipose tissue may be a more reliable prediction of body burden than scrum levels because of the high adipose/serum PBB partition ratio (Anderson 1985). However, once a stable correlation between adipose/serum levels has been characterized, serum levels are a better choice for surveillance and monitoring (Anderson 1985). Further studies on the predictive value of levels of PBB (particularly congeners) in serum and adipose tissue in individuals exposed to PBBs for acute, intermediate, and chronic durations would provide valuable information that could lead to early detection of PBB exposure. 

Polybrominated biphenyls (PBBs) and polybrominated diphenyl ethers (PBDEs) are each classes of structurally similar brominated hydrocarbons. PBBs are a class of chemical compounds in which 2 10 bromine atoms are attached to the biphenyl molecule. PBDEs are a class of chemical confounds in which 2 10 bromine atoms are attached to the diphenyl ether molecule. Monobrominated structures (i.e., one bromine atom attached to the molecule) are often included when describing PBBs and PBDEs. The general chemical structures of PBBs and PBDEs are similar when viewed in one dimension, differing only in an ether linkage, as shown below ... 

Polybrominated Biphenyls. PBBs are no larger being imported or exported except possibly in small quantities for laboratory uses. PBBs have not been imported from other countries into the United States, except in finished products (Neufeld et al. 1977). The two companies that manufactured octa- and decabromobiphenyl in the United States between 1976 (0.805 million pounds) and 1978 exported all of their products to Europe (Naifeld et al. 1977). 

Polybrominated Biphenyls. PBBs have been identified in at least 9 of the 1,613 hazardous waste sites that have been proposed for inclusion on the EPA National Priorities List (NPL) (HazDat 2002). However, the number of sites evaluated for PBBs is not known. The frequency of these sites can be seen in Figure 6-1. Of these sites, all are located within the United States. 

Polybrominated Biphenyls. PBBs existed predominantly in the particulate phase in the atmosphere. Particulate phase PBBs are removed from the atmosphere by wet and dry deposition and should not travel long distances in the environment. In water, PBBs are expected to absorb strongly to suspended solids and sediment, and may bioconcentrate in aquatic organisms. The volatilization of PBBs from water to air is not expected to be important due to attenuation by adsorption in the water column. In soil, PBBs are adsorbed strongly and will be immobile. Volatilization of PBBs from soil to air is not important due to the low volatility of PBBs and strong adsorption of PBBs to soil. 

Polybrominated Biphenyls. PBBs do not readily translocate from soil to plants via root uptake (Jacobs et al. 1976, 1978). Therefore, PBBs may not bioconcentrate in plants. However, plant uptake data are limited, audit will be helpful to develop additional plant uptake data. Brominated biphenyls with bromine substitution 6 or less will bioconcentrate in aquatic organisms (Gobas et al. 1989 Norris et al. 1973 Opperhuizen et al. 1985 Zitko 1979 Zitko and Hutzinger 1976). PBBs are preferentially stored in the adipose tissue of animals (Kimbrough 1987). Although PBBs have been detected in fish-eating birds... 

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