Polybrominated diphenyl ethers PBDEs sources

Sites near industrial areas in the Ebro have been found to have the highest concentration of priority contaminants [15, 47—49], while dispersion of agricultural products by drift, runoff and drainage has resulted in residues being found in ground-waters, rivers, coastal waters and lakes far from point sources [50]. Priority contaminants in aquatic environments include persistent organic pollutants (POPs) such as dichlorodiphenylethylenes (DDT) and polybrominated diphenyl ethers (PBDEs). 

Ramu, K., Kajiwara, N., Sudaryanto, A., Subramanian, A., Lam, P.K.S., Zheng, G.J., Prudente, M., Tana, T.S., Viet, P.H., Tanabe, S., 2005. Asian Mussel Watch Program Sources and distribution of polybrominated diphenyl ethers (PBDEs) and organochlo-rines contamination in coastal waters of Asian countries. Organohalogen Compd. 67, 1054-1057. 

Schecter, A., Papke, O., Joseph, J. E., Tung, K. -C. (2005) Polybrominated diphenyl ethers (PBDEs) in U.S. computers and domestic carpet vacuuming possible sources of human exposure. J. Toxicol. Environ. Health A., 68 501-513. 

Sjodin, A., Papke, O., Eocant, J. -E., Jones, R. S., Pless-MuUoli, T, Leontjew Toms, L.-M., Herrmann, T., Mueller, J., Needham, L. L., Patterson, D. G. Jr. (2006) Concentration of polybrominated diphenyl ethers (PBDEs) in household dust from various countries - is dust a major source of human exposure Organohalogen Cpds., 68 2181-2185. 

Hale RC, Kim SL, Harvey E, La Guardia MJ, Mainor TM, Bush EO, Jacobs EM. Antarctic research bases local sources of polybrominated diphenyl ether (PBDE) flame retardants. 

The importance of chemical safety is illustrated by Schecter, Papke, Tung, Staskal and Birnbaum [7]. The report stated that polybrominated diphenyl ether (PBDE) flame retardant chemicals had been found in food taken from the shelves of a supermarket in Dallas, Texas. The report also revealed that levels of contamination were higher in the US than those reported from similar studies carried out in other countries. The research goes on to suggest that a key source of contamination measured in people worldwide may result from polluted items in their individual diets. Other evidence of food contamination gave rise to the advice to eat not more than two portions of oily fish each week due to the likely presence of a mercury build-up in the flesh of such fish. 

No matter the source, flame retardants, especially the polybrominated diphenyl ethers (PBDEs), are coming under scrutiny because they are persistent organic pollutants (POPs). They are appearing in human samples, most notably serum, adipose fat tissue, and breast milk. PBDEs are also under investigation as potential endocrine mimickers or endocrine disrupters. As a result, PBDEs are the most highly regulated flame retardants. Their environmental fate will continue to be a topic of research for years to come. 

The presence of ethers in the atmosphere is almost entirely the result of direct emissions from anthropogenic sources (e.g., Arif et al., 1997 Intergovernmental Panel on Climate Change, 2001 Johnson and Andino, 2001 http //en.wikipedia.org/wiki/Ethers and references therein). These sources can be quite varied and species dependent for example, many ethers are commonly used as industrial solvents many are formed as combustion intermediates and in the burning of biomass various branched ethers (e.g., methyl tert-butyl ether) are (or have been) used as fuel additives to increase octane number and reduce CO emissions dimethyl ether has being proposed as an alternative diesel fuel many fluorinated species have been manufactured, evaluated and used as possible chlorofluorocarbon (CFC) and hydrochlorofluorocarbon (HCFC) replacement compounds some halogenated species are used as inhalation anaesthetics or as chlorofluorocarbon replacements and polybrominated diphenyl ethers (PBDEs) are used as flame retardants. There are no major routes to ether formation in the atmosphere itself. 

The saga of brominated flame retardants offers a cautionary tale for the chemical industry.65 These chemicals, developed in the early 1970s, are used in a wide range of consumer products, such as furniture, foam, and plastic casings of electronic devices. In 1998, Swedish scientists reviewing archived human breast milk samples discovered that certain flame retardant chemicals (polybrominated diphenyl ethers, or PBDEs) had doubled in concentration in Swedish breast milk about every five years over the preceding twenty. This was a source of concern, as studies of laboratory animals had shown that PBDEs dismpt thyroid hormones. Such dismption yields neurobehavioral effects similar to those of PCBs (polychlorinated biphenyls), whose manufacture the United States banned in 1976. 

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