Heavy metals cause further troubles

By Hepeng Jia, Peng Tian and Zhiguo Xu /Beijing and Jiyuan, China 

Despite repeated media exposure and subsequent government crackdowns, further cases of heavy metal pollution and poisoning have been reported across China. 

Shortly after cases of lead poisoning in Shaanxi Province’s Fengxiang County and cadmium poisoning in Hunan Province’s Liuyang city sickened thousands of children in late July and early August (see Chemistry World China, September-October 2009, pC2), extremely high levels of heavy metals in the blood of tens of thousands of residents have been reported in Hunan’s Wugang, Henan Province’s Jiyuan, Fujian Province’s Shanghang and Yunnan Province’s Kunming. 

Many environmental experts believe these reported cases are only the tip of the iceberg. 

Startling scenes 

Heavy metals are those with a density higher than 5 g/cm3. These include 45 elements, such as gold, lead and mercury. Arsenic is also often ranked as a quasi-heavy metal because of its similar toxicological effects. 

After wide media reports of the heavy metal poisoning in Fengxiang and Liuyang, residents in regions with heavy metal smelting industries rushed to test their blood, including those in Jiyuan, a city famous for its lead industry. 

To their dismay, in late August, among the 3,108 children aged under 14 in villages near Yuguang Gold & Lead - Asia’s largest lead smelting firm - and other major smelting plants, 1,008 were found to have lead levels in their blood of more than 250 ug/l. The level considered safe by the US Centers for Disease Control and Prevention (CDC) is 100 ug/l. 

To make things worse, when some residents went to their local health centre to retest their children, they found that in many samples the lead level was twice that found in the initial tests carried out at Jiyuan People’s Hospital. The highest reported lead levels were 635 ug/l - more than six times the US CDC limit. Officials at Jiyuan health authority say that the higher figures reported by the second testing round were a result of more advanced equipment bought in after the government became aware of the serious situation. 

In Jiyuan, hospitals and medical centres refused to test adults’ blood for lead, saying there was insufficient equipment. The decision widely upset residents, many of whom have lived with the lead smelters for decades. 

Excessive amounts of heavy metals can stunt children’s growth, cause muscle weakness and potentially harm the brain. So far, there has been little research on the impacts of high heavy metal levels on adult health. 

In late August, the Jiyuan government closed all small lead smelters and major smelting facilities in Yuguang along with other big plants. 

However, villagers and reporters coming to investigate the pollution in mid October found that at night, flues of the closed plants began to pump out emissions again, though local government denies the allegation. 

Economic woes 

Jiyuan government does not seem prepared to keeps its lead smelters closed for long. If the plants remain closed, it would be ’a serious attack to our economy,’ said Jiyuan mayor Zhao Suping at a conference about the poisoning held in mid October. 

Zhao’s viewpoint is understandable. Strong demand for heavy metals is unlikely to drop due to fast economic growth in China, particularly in the heavy metal industries.

In Hunan Province, with an annual output worth more than Yuan100 billion (US$14.7 billion), the non-ferrous metal industry - which mainly outputs heavy metals - accounts for one tenth of its GDP (gross domestic product). 

In addition, China has become a major supplier of heavy metals to the international market. The environmental disasters associated with heavy metals and the subsequent government crackdowns on factories since August have repeatedly pushed up lead prices on the London Metal Exchange. 

An expert who was a member of the central government’s inspection team sent to Fengxiang admitted that the real problems in local environments are even worse than those exposed by the media. ’But often, we cannot speak the truth because it could be disastrous attack to the local economy,’ says the expert, who refused to be named. 

Pains in science community 

Pushed by the spate of heavy metal pollution cases, the Ministry of Environmental Protection recently announced it had passed the draft plan of a comprehensive scheme to fight heavy metal pollution, which could be released and implemented by the end of the year after further revision.

Details of the plan are unavailable. But it is rumoured by scientists that the environmental ministry will also introduce a comprehensive research programme to estimate the real scale of heavy metal pollution, research easy detection methods and promote restoration of polluted soil.

Although heavy metal pollution is a major environmental challenge in China, research into the topic is in decline.

According to Zhou Qixing, dean of the College of Environmental Science and Engineering of Tianjin-based Nankai University, this is because heavy metal pollution is not a big problem in the West, and academic studies of the subject in Western countries correspondingly reduce. Chen Tongbin, a senior scientist at the Institute of Geographical Sciences and Nature Resources of the Chinese Academy of Sciences, explains further: ’The situation meant papers in the field were more difficult to publish, and science funding in China is shifting to more hot areas like persistent organic pollutants.’

Huo Xia of Guangdong Province-based Shantou University, who investigates the link between heavy metal pollution and human health, blames science funding agencies in China, who often prioritise hot research areas rather than the solution to the problems facing society in reality. 

’In addition, too few studies have been done on the links between heavy metal pollutions and human health,’ Huo told Chemistry World. ’This situation must be changed if we want to save people.’