BEIJING -- China customs uncovered 49 cases of hazardous waste smuggling last year, involving a total of 8,002 tons of solid waste, Xinhua learnt from the General Administration of Customs (GAC) on Wednesday.

The GAC said most of the cases involved industrial waste and domestic waste from the European Union, the United States, the Republic of Korea and Japan.

China's thirst for raw materials has in recent years produced a surge in imports of waste materials for recycling, but the presence of hazardous waste has raised concerns over potential dangers to the environment.

The GAC and the State Environmental Protection Administration have begun a campaign to identify kingpins in the hazardous waste smuggling business. The investigation will last until the end of June.

China has joined the Basel Convention on the Transboundary Movement of Hazardous Wastes and Their Disposal. The Convention, which took effect in August 1992, aims to prevent the export and import of hazardous waste.