FENGXIAN, Aug. 25 -- Ask people about lead poisoning in the lush mountains of northwestern China's Shaanxi province, and nearly everyone can recall a case.
Lead poisoning in children living near a lead and zinc smelter in Changqing in Shaanxi and a manganese smelter in southern Hunan province made international headlines this month, after parents protested.
Yet these cases are far from unique. Interviews this weekend showed that lead poisoning is endemic among villages near Chinese smelters.
In Fengxian, where smoke billows from a Dongling Group zinc smelter, two wan and listless toddlers were diagnosed with high levels of lead in their blood earlier this year. Villagers requested but did not get testing for 30 other children.
"These problems are really common actually. It's just that the Dongling case in Changqing got some attention," said a villager surnamed Tu. Older villagers developed circulatory problems and some workers at the plant got too sick to work.
"This environmental pollution is not unique to Fengxian. It's all over."
Lead poisoning due to air and water pollution from poorly regulated smelters and mines haunts the valleys of the ore-rich Qinling range, in a poor and remote part of China.
The problem dogs heavy metals bases in Hunan, Henan, Yunnan and Guangdong provinces. Closing polluting plants has pushed the industry to poorer areas where any investment is welcome.
After contaminated drinking water led Hunan province to shut dozens of metals plants in the cities of Zhuzhou and Xiangtan in 2006, the industry moved to the south and west of the province.
One of the new frontiers was Wugang, where authorities detained two manganese smelter executives this month after 1,350 children were found to have excessive levels of lead in their blood. The general manager is still on the run.
The shift to poorer regions echoes the migration of the lead smelting industry to China over the last decade, as stricter environmental laws forced smelters in richer countries to close.
China's output of refined lead rose nearly 20 percent in 2008 to 3.26 million tonnes. Output feeds the Chinese battery industry, the world's largest, which then exports worldwide.
The casualties of China's heavy metals industry only get attention when officials respond to cases too large to ignore.
In late 2005, two of China's largest zinc smelters shut temporarily after cadmium contaminated the Pearl River Delta and the Xiang River, sources of drinking water for millions in Hunan and Guangdong Provinces. Cadmium hurts kidney and lung function.
Elevated cadmium levels also showed up in tests of children near the Dongling Group's lead and zinc smelter in Changqing, Shaanxi Province, this month. Parents attacked the smelter after 800 children tested for high levels of lead in their blood.
Authorities have not tested anyone over 14.
Children are most vulnerable to lead poisoning because they are still developing, but smelter workers also fall sick because they absorb it through their skin.
A person who ingests large amounts of lead may develop anaemia, muscle weakness and brain damage.
"My dad couldn't stand it any more, so he quit working. It got so he could only work 20 days at a time, then he would have to stop," said a young woman surnamed Zhang.
"Dad's tummy would always hurt. When it's bad, he doesn't want to eat and has no energy."
Zhang's husband now works at a different smelter after her family's employer, Shaanxi Nonferrous Metals Holding, halted work at its 50,000 tonne Wenjiangsi lead smelter earlier this month.
Workers at the Wenjiangsi plant said the plant's internal clinic regularly treats workers who get to the point that they cannot work. They resume work when they feel better.
"It's not a problem if you drink a lot of alcohol," said a young man in a blue work uniform.
In Shaanxi, which is dominated by heavy industry, the smelter operators have powerful connections. Police and plainclothesmen put pressure on any residents who talk to reporters.
Dongling, China's fourth-largest zinc producer, was founded by Li Heiji, one of the richest men in nearby Baoji city and a delegate to China's legislature, while Shaanxi Nonferrous is a state-owned firm with smelters across the province.