Contaminated sites are increasing in major cities, as urban sprawls has overrun many pollution factories, pushing them to new locations, China Daily reports. This serious issue was given priority status at the annual sessions of the National People’s Congress and the Chinese People’s Consultative Conference (CPPCC), last week.

Jia Kang, a CPPCC National Committee member, called for a soil protection law immediately. Jia, who also heads the institute of fiscal science at the Ministry of Finance, said that land pollution is already threatening the sustainability of economic growth and social stability.

China is suffering direct economic losses caused by farm pollution, which leads to reduced grain production and public questions over food, Jia said. Land pollution will also take a toll on Chinese grain export and threaten the country’s ecological security, he added.

Last November, an affordable compound, with 2,400 apartments, was constructed in Wuhan, capital of Hubei Province, on the site of a previous chemical plant. Those who were qualified to purchase the property were considered lucky at the time.

The construction was almost finished when an environmental review by China University of Geoscience discovered that the site was contaminated with antimony, a metallic element that can cause heart and lung problems.

Plastic sheeting was spread over 21,000 squares meters to insulate the contaminated soil, and new soil was spread on the top of the plastic. The measures cost the developer 6.8 million Yuan (1.03 million dollars), according to The Beijing News.

“Pollution incidents associated with land contamination are becoming a growing concern In China”, said Jian Xie, a senior environmental specialist at the World Bank. “Many brownfields sites, if not managed well, will pose an environmental and health hazard in China`s most densely populated areas, as well as an obstacle to urban and economic development.”

A recent study conducted by World Bank shows that China’s rapid urbanization has resulted in the redevelopment of industrial land once occupied by old factories that were placed on the cities’ perimeters decades ago.

In Beijing, more than 100 polluting factories inside the Fourth Ring Road were relocated, leaving as much as 8 million square meters of industrial land to be redeveloped. Shanghai, Chongqing, Guangzhou and other big cities are in a similar situation.

Soil contamination usually involves toxic heavy metals from steel, iron and smelting plants; persistent organic pollutants (POPs) from pesticide residues; organic chemical compounds from petrochemical industries; and electronic wastes.

Heavy metals and POPs rarely break down over time and can accumulate in the environment. They can be absorbed into the body through drinking water and food consumption, causing harm to organs or even cancer.

Experts estimate that contaminated industrial sites in the country number 300,000 to 600,000.

Remediation for such sites has become urgent as the country’s rapid urbanization creates an enormous demand for usable land. This procedure requires both funding and technical guidelines from the government.

In China, the most commonly used remediation practice is to remove the polluted soil, which is then deposited into a landfill or burned, and replace it with clean soil.

Some developers argue that they should not have to pay the costs of remediation since they were not the people who cause the pollution.

For Wang Shuyi, director of the Research Institute of Environmental Law at Wuhan University, the polluters should pay for the remediation. In cases where seems impossible to identify who is liable, the money could come from public funding, he said.

The existing laws and regulations, such as the Environmental Protection Law and the Water Pollution Prevention and Control Law, are not able to effectively tackle land pollution, Jia said.