Soil pollution by legions of mines has severely worsened in south China's Guangdong Province since 2008, according to a Chinese researcher.

A provincewide survey conducted by the Guangdong Institute of Eco-Environment and Soil Sciences shows 40 percent of the province's soil is tainted with heavy metals, Thursday's China Daily quoted Wan Hongfu, a researcher with the institute, as saying.

Guangdong is home to more than 3,000 mines.

"Farmland near mines are typically polluted," said Wang, who added a nationwide soil pollution investigation was also initiated in 2005 in a bid to address the problem, but no result is publicized by now.

Dabaoshan Mine, for one, is believed to be one of the main polluters in Shaoguan, a mountainous city in Guangdong.

Known to produce some 6,000 tonnes of copper and 850,000 tonnes of iron ore annually, the mine has produced a growing amount of sludge and wastewater that has contaminated some 585 hectares along the lower sections of the Hengshui River running atop the mountain.

Mining for iron ore exposes naturally occurring heavy metals like arsenic and cadmium, both of which are carcinogens, Wan said.

"Without adequate and advanced water treatment facilities, water tainted with high levels of these metals poses great threats to soil," said Wan, "and they are linked to development of various forms of cancer."

More than 250 cancer-related deaths associated soil pollution, have been recorded in Shangbai Village at the foot of the Dabaoshan mine since 1987.

It is said that the majority of cancer cases have involved liver or intestinal complications, and that skin disorders and kidney stones are also prevalent.

Heavy soil pollution has also been blamed for declining yield of crops grown on farmland in the village.

Provincial Environmental Protection Department officials have promised to introduce concrete measures to fight pollution in the surrounding areas of Dabaoshan Mine in the near future.

(Xinhua News Agency July 15, 2010)