Heavy-Metals a Curse on Mine Riches

Feb 24, 2011     Email"> PrintText Size

For the many local people tied to the mining industry in Gejiu, a county-level city in Honghe Prefecture in southwest China's Yunnan Province, the rich tin deposit stored beneath the soil haunts like a curse.

With a population of more than 450,000, Gejiu's tin reserves at over 900,000 tons account for one third of the national total and one sixth of global stock.

Yet as people rush in to capitalize on this natural bounty, their crude methods also mean the accompanying toxic heavy-metal arsenic produced in the mining process is left untreated in open fields and ultimately washed into rivers by rains or even seeps under the ground soil.

As a result, the very natural resource that has enriched the locals also comes back as a curse as more and more of them begin to develop cancer from arsenic poisoning either by direct exposure in tin mining or through soil and water contamination.

Nationally over 70 percent of the arsenic generated in tin mining ends up as tailings and by 2008 about 1.2 million tons of arsenic is estimated to have been discharged into the environment, the China Economic Weekly reports, citing research data released by the Institute of Geographic Sciences and Natural Resources Research (IGSNRR) under the Chinese Academy of Sciences (CAS).

Cancer rates among the locals in Gejiu used to be as high as 2 percent and the average life expectancy stood at merely 50 years, the report says.

The serious contamination forced many locals to abandon farming in their hometowns and to migrate to find work.

The case of Gejiu is just one of many similar tragedies plaguing China's resource-blessed regions. In 2001, a tailing dam in Guangxi's Huanjiang Maonan Autonomous County collapsed in a major flood. The flood water laced with heavy-metals inundated fields downstream, killing off nearly all the crops. The 100-kilometer-long Diaojiang River, which empties into the Zhujiang River, was also contaminated.

Research papers obtained by the newspaper from the environment science center of IGSNRR listed several other areas in the country where the soil is heavily contaminated by arsenic, including Liannan in Guangdong, Nandan in Guangxi, and Hunan's Changning, Changde and Chenzhou.

The Xiangjiang River, which runs 856 kilometers and irrigates almost half of Hunan Province, also receives more than 90 percent of the province's arsenic, cadmium and lead from huge quantity of waste water discharge.

All the heavy-metals were finally condensed in the soil and absorbed by crops. China's Ministry of Land and Resources estimated that each year 12 million tons of grain in the country was contaminated, enough to feed 40 million people, the report said.

Luo Zhongwei, a researcher with the Institute of Industrial Economics at the China Academy of Social Sciences, believes local government, which has the power to ratify the exploitation of small and medium-scale mines, should be held accountable for the chaotic situation in the country's mining industry which is ill-regulated, outdated in technique and lacks overall planning.

These local governments should have their ratifying powers annulled and be forbidden from investing in mining enterprises, Luo was quoted in the report as saying, who also suggests the establishment of a coordinating mechanism on the distribution of the profits from mine exploitation.

The report comes as a long-awaited project to tackle heavy-metal pollution in China has been approved by the State Council as part of the 12th Five-Year Plan (2011-2015).

The national blueprint for 2015 has set an emission-reduction target for five heavy metals, in key polluted areas, at 15 percent from 2007 levels, Environment Minister Zhou Shengxian, told a recent televised conference.

The metals are lead, mercury, chromium, cadmium and arsenic.

(Source:CRI English)