THERE are several kinds of toxic wastes that are dumped in Asia. According to Greenpeace, among the noxious wastes that have been shipped to Asia since 1990 are aluminium, cadmium, copper, nickel, tin, zinc, other non-ferrous and ferrous metals, ash and residues, computer scrap, plastic, medical and radioactive wastes.

The contention of developed countries that most of these wastes, especially plastic and metal scrap, can be recycled, is in reality a myth. Greenpeace points out that when plastic is melted, its chemical structure changes and in the process of burning, it may release cancer-causing gases such as benzene. Yet, workers in many Asian plastic reprocessing factories are exposed to dangerous fumes from burning plastic without adequate safety clothing or breathing apparatus.

The same holds true for the thousands of tonnes of computer waste that the US ferries to Asia every year. In 1993, China, Hong Kong and the Philippines received over 1,800 tonnes of "technojunk". In China, cables are stripped to retrieve copper wire and the remaining waste is either burned or stockpiled. Ironically, the US Environmental Protection Agency recognises that burning computer keyboards produces brominated dioxins, which are linked to cancer, immuno-suppression, developmental effects in children and sex changes in offspring.

Asian countries also pay the price for indiscriminately importing metal scrap. "Ashes and residues" often contain dangerous substances such as arsenic, cadmium and lead, mixed with recoverable materials like tin or zinc. In the process of recycling or dumping, these heavy metals may be released directly into the environment.

Advocates of a ban on the waste trade claim that waste "recycling" often takes place in enterprises with inadequate or no facilities, thereby endangering the health and environment of the local population.