Marine life in the Pearl River contain excessive trace metals that may cause cancer, Ta Kung Pao newspaper reported yesterday.

The Hong Kong Polytechnic University and Guangzhou Institute of Geochemistry under the Chinese Academy of Sciences started the research in 2003, which analyzed 58 samples collected in the Pearl River estuary, including fish, shrimp, crab and conches.

The research shows a kilogram of shrimp contained 0.835 milligram cadmium, more than 16 times of the national standard (0.05 milligram). The content of lead in fish was 2.2 mg per kilo, also exceeds the national standard, 1 mg per kilo.

"Cadmium and lead may cause cancer and damage the haemopoietic system and the central nervous system," Zhang Gan, a professor who headed the research team in the institute, told China Daily yesterday.

"The concentrations of various toxic trace metals are moving up."

Zhang said the growth of trace metals was mainly derived from pollution, particularly electronic trash.

Electronics boosted the Pearl River Delta's economic development but heavily polluted the river, which the local people rely on for their existence, Zhang said.

But Zhang noted that a part of the trace metals are produced by nature. The main geological structure of the region is granite, which heavily contains lead and zinc.

Moreover, the exploitation of mineral resources in the upper reaches of the Pearl River also helped pollute the lower reaches and the estuary.

Because the upper reaches of the Pearl River stretch to the Guangxi Zhuang Autonomous Region and provinces of Jiangxi and Yunnan, Guangdong Province alone cannot control the exploitation and clean up the river, he said.

Asked for his reaction to the two institutions' findings, Chen Guangrong, deputy director of Guangdong's Environmental Protection Bureau , told China Daily yesterday: "I did not hear of the research, and we have our own tests regarding the pollution situation of the Pearl River." He declined to reveal any details.

Chen Xiancheng, director of the Pearl River Renovation Office of the bureau, announced earlier this month that Guangdong will earmark 150 million yuan (US$18 million) to build up a zoology base in Jiangxi within this year to make the water from the Pearl River clean, and promised more monitoring stations will be built in the upper reaches of the river.

The Guangdong Provincial Oceanic and Fishery Administration said it would be difficult to ban people from fishing in the river. But he cautioned against eating too much of the tainted marine life.

Administration statistics show 1.12 million tons of marine life were in the Guangdong market from January to September, most of which were caught in the estuary of the river.

(China Daily December 1, 2005)