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Polybrominated diphenyl ethers (PBDEs) are widely utilised brominated fire retardants in plastics, electronic circuitry, television sets, building materials and textiles. In computers, these compounds are commonly used in printed circuit boards, components such as connectors, cables, plastic covers and parts of keyboards and monitors. It is estimated that 2 and 4 x 109 kg of so-called ‘‘eWastes’’ which was recycled or dumped between 1997 and 2004 (Martin et al. 2004). Thus, PBDEs may constitute a current threat to the environment, not only because of their ubiquitous presence in manufactured goods, but also the strong possibility of their continued release into the environment for many years to come, even if stringent worldwide regulations were to be adopted now. PBDEs are amongst a group of xenobiotic compounds considered to produce estrogenic effects and cause reproductive failures. PBDEs are strikingly similar to PCBs, which are known for their recalcitrance and bioaccumulation potential in humans and wildlife. PBDEs have a higher propensity for bioaccumulation in the food web than PCBs. Although not as well studied as PCBs, their toxicological properties in vertebrates, including humans (especially interference with the thyroid system) are cause for concern and continued research. Limited data are available on the presence and levels of PBDEs in environmental compartments, especially in Asia.

Unconfirmed reports of major deposits of plastics and electronic parts in China and India suggest the existence of important sources of PBDEs. China’s role as one of the significant dumping grounds for many of the world’s unwanted computers and redundant pieces of electronic equipment reflects efforts by developed countries to protect their own environments.Many governments are encouraging the recycling of computers to keep them out of landfills and prevent toxic contamination in soils and drinking water, but the dismantling of computers to generate reusable raw materials is labour-intensive and expensive. In a survey in California, the US EPA (1999) discovered that the cost of dismantling and reusing the materials in a computer monitor in the USA is about 10 times the cost of shipping it to China for disposal.Exports of eWastes appear to be motivated entirely by brute global economics. Unregulated market forces cause toxic wastes to run down the path of least resistance, which in this instance are the developing countries of the world, such as China and India.A free trade in toxic wastes leaves the poorer countries of the world with the choice of poverty or poisoning, choices that are obviously objectionable and unfair.How severe is the problem in these countries? We simply do not know!

Extracts from a Research Paper by Michael Martin, Paul K.S. Lam, Bruce J.Richardson. "An Asian quandary: where have all of the PBDEs gone?" Marine Pollution Bulletin 49 (2004) 375–382.

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