Mounds of foul-smelling waste stand rotting in the cold air. The dark, smog-choked sky lowers menacingly and the river runs slowly, a black tide of toxic sludge. Sandwich boxes carrying the labels of British supermarket chains poke through the dumps; crumpled pizza wrappers and plastic bags blanket the streets. Working in the middle of it all are children, some as young as four, sifting though the waste with their bare hands.

Lianjiao, a remote Chinese village in the booming southern province of Guangdong, is a long way for a plastic bag to travel; but it is where almost all British supermarket carrier bags end up. And the foil-lined crisp packets. And the triangular hard plastic packaging for your bacon, lettuce and tomato sandwiches from a top high-street chain. Because China is rapidly becoming Britain's biggest rubbish dump.

Regardless of how carefully you separate your waste, there is a good chance a disposal firm will dump it all in together with other kinds of plastic trash and ship it to the developing world to be dealt with by a family of migrant workers earning a pittance. They will deal with the salad-bar container, the pistachio ice-cream container and the superfluous bag for carrots in your shopping basket in a variety of different ways - it may be recycled, it may become landfill or it may simply be burnt.

Whatever happens, it is generally not a priority for the waste disposal company. Britain dumps around two million tonnes of waste in China every year, everything from plastic mineral water bottles to shopping bags and other forms of superfluous packaging from some of the country's biggest supermarkets.

A huge amount of it arrives in 10-ton shipments in Lianjiao, a village which has become a centre for processing plastic waste - much of it from Britain. The high levels of pollution in the nearby river and the poisoned sky are the price of waste disposal in the developing world. So too are the many and varied health complaints suffered by the local population, who risk multiple skin ailments and exposure to potent carcinogens as they touch the contaminated materials. Poisonous chemical effluents stream into their water supply, turning it black or lurid red, and studies by Greenpeace show that acid rain is the norm in this region. Children are prone to fevers and coughs. Their skin is often disfigured by the toxic plastic waste they have to process.