More than 1,500 times the permitted level of heavy metal has been found in soil in China’s south-central Hunan province, according to an unofficial environmental study.

Among the heavy metals found in the soil, the amount of cadmium was 200 times more than that permitted by China’s soil environmental quality standard, China Economic Weekly reported, quoting the findings by non-profit organisation Changsha Shuguang Environmental Charity Development Centre.

The centre, set up in August last year, spent more than 500 days collecting samples from more than 10 cities along the Xiang River. Its findings – the largest unofficial research into the region in recent years – were published on November 15.

The authorities have not made any official response to the report.

In April, a national survey on soil pollution found that national soil pollution was 16.1 per cent higher than the quality standard, and that the main pollutants were mercury, cadmium, arsenic and lead.

According to the Ministry of Environmental Protection’s website, a detailed survey on soil pollution in Hunan had been completed as early as July 2009, but was not released.

Hunan’s non-ferrous metal mines generate almost 50 million tonnes of waste a year. Of the more than 160 types of minerals that have been discovered in the world, 140 – including tungsten, antimony, bismuth, zinc, lead and tin – can be found in the province, which has a mining history that spans over 2,000 years.

Waste water from mining is often used to irrigate farmlands, and the water, which contains cadmium among other pollutants, has been poorly managed amid rapid development.

Hunan residents said the water soil and air pollution in the province had given rise to a range of puzzling illnesses as well as cancer. In June, three Hunan officials were suspended after excessive levels of lead were found in the blood of more than 300 children in the province.

Environmental Protection Minister Zhou Shengxian said on Monday that the government would set up a system to monitor pollution and enforce stronger regulations.

“The focus of reform in ecological and environmental systems will be to build and improve a stringent pollution prevention and control mechanism, environmental evaluation process, administration system and early warning system,” Zhou said at the annual session of the China Council for International Cooperation on Environment and Development.

Vice-Premier Zhang Gaoli, who was also at the meeting, said: “China will insist on efforts to optimise economic structures to reduce pollution. There is zero tolerance for the development of polluting industries.”