Several seafood wholesale markets in Shanghai have stopped selling products from Hubei and Henan provinces for fear that the products might be contaminated with malachite green, an anti-parasitic chemical that could cause cancer.

Local food and drug administration officials began conducting spot checks on seafood in local wholesale markets, supermarkets and restaurants Thursday. The products in question include soft-shelled turtles, salmon and shellfish. Results will be released in two weeks, officials said.

The Ministry of Agriculture (MOA) issued a warning last week about the possible contamination.

The MOA said the dye was used mainly in Hubei and Henan and most of their products are sold in Beijing, Tianjin and Shanghai.

The Tongchuan Road Aquatic Products Wholesale Market, the city's largest seafood market, stopped selling artificially raised sturgeon from Hubei yesterday.

"Because we aren't sure whether the fish is polluted or not, we had to make the decision," said Dai Honggen, the market's director of quality inspection.

The Huxi Aquatic Products Wholesale Market also stopped selling products from Hubei and Henan yesterday.

"If malachite green is found in any of the products, the food and drug administration will track the source and impose punishment on those responsible," said municipal government spokesperson Jiao Yang.

Gao Xuexiang, an official with the Shanghai Fishery Office, said: "Malachite green is quite toxic. It can cause cancer, malformations and mutations."

Gao added, "The chemical was banned in 2002. But some fish farmers still secretly use it to treat parasitic and fungal infections in fish because it is cheap."

(Shanghai Daily July 15, 2005)