China for years has welcomed the world's trash, creating a roaring business in recycling and jobs for tens of thousands. Now authorities are clamping down on an industry that has helped the rich West dispose of its waste but also added to the degradation of China's environment. The Chinese campaign is aimed at enforcing standards for waste imports after Beijing decided too many were unusable or even dangerous and would end up in its landfills.

Under the crackdown, dubbed Green Fence, China has rejected hundreds of containers of waste it said were contaminated or that improperly mixed different types of scrap.

Pollution crackdown

It is abruptly changing a multibillion-dollar global industry in which China is a major processing centre for the world's discarded soft drink bottles, scrap metal, electronics and other materials. Whole villages in southeast China are devoted to processing single products, such as electronics. Household workshops break down discarded computers or appliances to recover copper and other metals. Some use crude smelters or burn leftover plastic and other materials, releasing lead and other toxins into the air. Green Fence is in line with the ruling Communist party's pledges to make the economy cleaner and more efficient after three decades of breakneck growth that fouled rivers and left China's cities choking on smog.

Brian Conners, who works for a Philadelphia company that recycles discarded refrigerators, says buyers used to visit every week looking for scrap plastic to ship to China for reprocessing. Then Beijing launched its crackdown in February aimed at cleaning up the thriving but dirty recycling industry.

"Now, they're all gone," said Conners, president of ARCA Advanced Processing.

American and European recyclers send a significant part of their business to China and say they support higher quality standards. But stricter scrutiny has slowed imports and raised their costs.

"While we support Green Fence, it has increased our cost of doing business," said Mike Biddle, founder of MBA Polymers, a plastics recycler with facilities in California, Europe and southern China. "It takes longer and there are more inspections."

At the same time, people in the industry say recyclers who invest in cleaner technology might be rewarded with more business as dirtier competitors are forced out of the market. China's recycling industry has boomed over the past 20 years. Its manufacturers needed the metal, paper and plastic and Beijing was willing to tolerate the environmental cost. Millions of tonnes of discarded plastic, computers, electronics, newspapers and shredded automobiles and appliances are imported every year from the United States, Europe and Japan.

Poisoning the environment

But environmentalists have long complained that the industry is poisoning China's air, water and soil. And Beijing, ever vigilant about possible threats to the legitimacy of one-party rule, now wants to be seen as addressing increased public awareness and concern over pollution.

"The waste-recycling system in China really needs to be updated to reduce pollution," said Lin Xiaozhu, head of the solid-waste program for the Chinese group Friends of Nature.

In Europe, electronics recyclers recover about 2.2 million tonnes of plastic and metal a year and send about 15 to 20 per cent of that to

China, says Norbert Zonnefeld, executive secretary of the European Electronics Recyclers Association. Its 40-member companies include electronics manufacturers and copper smelters. European recyclers welcome China's tighter enforcement because it will help them comply with European Union rules on tracking waste and ensuring it is properly handled, Zonnefeld said. Still, he said, some traders have run into trouble.

"I have heard material has been sent back," Zonnefeld said. "They were just gambling."

American trash

The United States relies even more heavily on China to recycle its waste.

Americans threw away 32 million tonnes of plastic last year: packaging, appliances, plates and cups, according to the U.S. Environmental Protection Agency. About 1.1 million tonnes was collected for recycling. About half of plastic soft drink and water bottles collected in the U.S. for recycling are sent to China, said Kim Holmes, director of recycling for the Society of the Plastics Industry in Washington. Nearly all plastic from U.S. electronics waste is exported to Asia, she said.

"The export market is a major component of the broader U.S. recycling industry," Holmes said in an email.

China allows waste shipments to contain no more than one per cent unrelated material. But customs officials say some were found to be up to 40 per cent unrecyclable trash.

"Some unscrupulous traders, in order to maximize profit, smuggle medical and other waste inside shipments, a direct threat to everyone's health," a Shanghai Customs Bureau statement said in April.