About 12.3 million hectares, or more than 10 percent of China's arable land, is contaminated by pollution and the situation is getting worse, the Ministry of Land and Resources said.

Arable land pollution, together with declining farm areas, posed a severe threat to the nation's food production, the Xinhua News Agency quoted an official from the ministry as saying yesterday.

The ministry announced this month that the country's arable land area had shrunk to 121.8 million hectares by the end of last October, with the loss of 306,800 hectares in the first 10 months of 2006.

Contaminated land suffered from polluted water, excessive fertilizer, heavy metals and solid wastes, the official said.

The ministry acknowledged that heavy metals alone had contaminated 12 million tons of grain and caused losses of 20 billion yuan ($2.6 billion) each year, adding that polluted grain would ultimately be a health hazard, Xinhua reported.

Sun Wensheng, minister of Land and Resources, called on the public to conserve land and other resources for sustainable economic growth yesterday, the 38th World Earth Day.

"China's economy keeps growing at a rapid rate and demand for resources is also mounting," he said.

"Thus, there has been more damage done to the environment from unsuitable resource exploration and development."

Sun reiterated that China must ensure that its arable land never shrinks to less than 120 million hectares.

"This not only is related to the social and economic development, but also vital for the long-term interests of the country," he said.

Fish released

In another development, 400,000 rare fish, including about 110,000 Chinese sturgeons, were released into the Yangtze River yesterday to save the river's fish stocks from being wiped out.

Decreasing river levels and pollution have taken their toll on fish stocks. The number of sturgeon that migrate to the Yangtze each year to spawn has dropped from 2,176 in 1987 to just 500 now, Chen Xihua, a researcher from the Yangtze River Fisheries Research Institute, said.