Opinion | China should release data on polluted soil

The high-profile emphasis on environmental protection at the Communist Party's 18th national congress was eye-catching. The news immediately boosted the A shares of environment-related industries, and spurred industry demands for timely information on the environment.

China's development to become the world's second-largest economy over the past 30 years has come at a heavy environmental price. Environmental management as a whole has been deteriorating despite minor improvements, while mass protests related to environmental issues have been on the rise. At the congress, officials pledged to improve environmental assessment, strengthen accountability and raise public awareness. To do this, they must insist on transparency.

On that note, it's disturbing that a long-awaited national survey on soil pollution has not seen the light of day. The study, a joint project of the Ministry of Environmental Protection and the Ministry of Land and Resources that started in 2006, was the first of its kind in China. The aim was to find out the extent of land pollution across the country, so measures, legislative and otherwise, could be taken to tackle the problem. The study was reportedly completed in 2010.

Yet, to date, the findings have not been made public; no effective action has been taken to clean up polluted land or assist those affected; no individual or group has been held seriously accountable for any damage; and no law has been introduced. The president's report at the congress identified environmental problems as a public health issue. It named three major types of pollution - water, air and soil - and called for strengthened measures to control and prevent pollution.

All three types of pollution are equally harmful, though the damage caused by soil pollution is not always easy to detect. The "itai-itai disease", a weakening of the bones caused by cadmium poisoning, is a dreaded pollution-induced disease in Japan. In China, high levels of cadmium have been detected in the blood, urine and hair of people living in rural areas, as documented by a 2011 Caixin report. What's worrying is that the extent of cadmium's harm to the body is still not fully known.

Soil pollution in China is among the worst the world has seen, according to data released in 2006 by the Ministry of Environmental Protection: some 150 million mu (10 million hectares) of the country's arable land was found to be polluted, while 32.5 million mu was being irrigated with contaminated water. In addition, 2 million mu of land was used as dumpsites. That adds up to a total of 184.5 million mu of polluted land, a tenth of the 1.8 billion mu of arable land in China. Also, it is estimated that every year, up to 12 million tonnes of food - or 20billion yuan's (HK$25billion) worth - are contaminated by heavy metal.

Inside sources told the media that even this did not reflect the full scale of the problem as the data was collected in the 1990s, and the situation would be far worse now. Late last month, the State Council introduced a plan to restore polluted soil, yet we're still waiting to be told the latest figures.