Studies Warn of Produce Grown in ‘Hot Spot’ Soil; Pingyang’s Ill Farmers
Wall Street Journal
By Nicholas Zamiska and Jane Spencer
NANNING, China — For nearly two decades, Lai Mandai regularly ate and sold beans, cabbage and watermelons grown on a plot of land a short walk from a lead smelting plant in her village.
Like dozens of other villagers who ate locally grown food, Ms. Lai, 39 years old, developed health problems. “When I did work, planting vegetables or cleaning the floor, I felt so tired, and my fingers felt numb,” Ms. Lai says. “I talked with other villagers. They had the same problems.”
Ms. Lai, along with 57 other villagers, was eventually diagnosed with high levels of cadmium, a heavy metal that can cause kidney disease and softening of the bones. Runoff from the factory — which the government tore down in 2004 — had contaminated the farmland and entered the food supply. A Chinese government report found that rice grown in the village contained 20 times the permitted level of cadmium.
China’s tainted food supply has fallen under heightened scrutiny after a shipment of wheat flour contaminated with a chemical used in fire retardants found its way into pet food and was linked to the deaths of U.S. animals in late March. Concerns have since soared over the safety of the country’s exports. The U.S. Food and Drug Administration recently told consumers to stop buying toothpaste made in China because it might contain poisonous diethylene glycol. Last week, the FDA sounded an alarm on farm-raised seafood from China, citing excessive levels of antibiotics and additives.
Yet after decades of industrial pollution, some of the worst contaminants making their way into the country’s food come from the soil in which it is grown. So far it hasn’t been determined the extent to which tainted crops such as rice, fruits and vegetables have been exported to the U.S. What is clear is that in contaminated areas dotting the country, residents have been eating such food for years or decades.
Pingyang, where Ms. Lai lives, is among the so-called hot spots in China where farmland lying in the shadow of factory smokestacks or mining operations has been contaminated by heavy metals. These elements can cause a sweeping range of health problems, from brain damage to cancer.
Chinese academics have written about such sites in more than a dozen studies over the past two years in Chinese and international scientific journals. In a study published earlier this year, researchers at the Guangdong Institute of Ecology found excessive levels of cadmium and mercury in Chinese cabbage grown in Foshan, a major manufacturing center in southern China. Last year, researchers at Lanzhou University published research showing that vegetables at four sites near the mining and smelting city of Baiyin in the Northwestern Gansu province contained hazardous levels of cadmium, lead and copper. A study of crops grown in the central city of Chongqing found excessive lead and cadmium levels in vegetables at 20 sites.
China’s government — which has been criticized by international critics for downplaying the extent of other recent health threats — has sounded an alarm. The Ministry of Land and Resources said in April that heavy metals had contaminated about 13 million tons of grain, and that 30.4 million acres, or more than 10% of the country’s arable land, is contaminated by pollution.
Mounting Concerns
Concerns are mounting internationally as China plays a growing role in the global food industry. The country’s exports currently account for about 12% of global trade in fruits and vegetables. China’s agricultural exports to the U.S. rose to $2.26 billion in 2006 from $133 million in 1980, according to the U.S. Department of Agriculture.
Other governments, including Hong Kong and Japan, systematically test imports from mainland China for metal contamination. But the U.S. FDA says it does virtually no routine testing of food imports for metals. Most of its standard tests on imports are aimed at identifying pesticide residues. Some state health departments and retail chains do their own testing for metals.
Foods from China containing high levels of lead have occasionally been discovered on U.S. supermarket shelves. In 2005, California issued a recall of sweet cured plums from the country after a routine spot test by state health inspectors found “excessively high levels of lead that could cause serious health problems.”
The FDA says the potential for heavy-metal contamination is on its radar, but its resources for testing are limited. “Our food supply is globalizing, and we need to be very focused on what’s going on outside our borders,” says Michael Bolger, chief of the Chemical Hazard Assessment Team at the FDA’s Center for Food Safety and Applied Nutrition. The agency said there is scant evidence so far that heavy metals in imports from China pose a health risk to Americans.
China’s soil contamination is caused by a range of factors. Mercury released into the air by coal-fired power plants is captured by raindrops, and transferred to the soil and groundwater. Groundwater is also polluted by runoff from factories, smelters and mining operations, and then used by farmers downstream from industrial operations to irrigate their crops.
Even in rural areas, far from industrial sites, heavy use of fertilizers has contributed to contamination. Fertilizers in China often contain high levels of metals, especially cadmium, which is found naturally in the same sedimentary rocks that contain plant-friendly zinc.
Rudimentary sewage-treatment systems throughout much of China mean that organic waste is routinely mixed with industrial waste. When sewage is recycled into fertilizer, it may contain large amounts of metals and other toxic material.
China’s contamination problem has been particularly acute in Pingyang, a village on the outskirts of the southern provincial capital Nanning. With small patches of farmland sprinkled among multistory apartment buildings, Pingyang is a testament to the urban sprawl that has blurred the lines between China’s countryside and cities. Residents plant green vegetables next to construction sites. Corn rises behind factories.
In 1965, the local government built a smelting factory for lead and antimony, a metal used in fireproofing electronics and other applications. For decades, the factory discarded waste in piles near farmland. Rains would wash the metals — including cadmium, a lead-production byproduct — into farmers’ fields, and into the ponds farmers used to water their crops.
A group of Chinese researchers arrived in Pingyang in 2002 after hearing villagers’ complaints. They tested for cadmium, lead, zinc and copper in residents’ blood and urine samples, as well as in vegetables and soil from around the area. In a study published in the journal Environment International in 2005, the researchers concluded that lead levels in the soil taken from parts of the village were “extremely high.” It is possible that villagers were also exposed to dangerous levels of cadmium in the air, researchers said.
Ms. Lai was among those poisoned. She had moved to Pingyang in 1989, when she was 21 years old, leaving her family to live with her husband, who worked in town as a welder. She first began to notice stiffness in her joints and fatigue when she was around 30 years old, a few years after she gave birth to her second son.
A senior official with the environmental agency in nearby Nanning, who declined to give his name, said his agency began testing the soil near Pingyang’s smelter as early as the 1980s, after villagers complained about problems with the soil. After confirming the ground was contaminated, his agency reported the problem to the local government and suggested shutting the smelter down. Nobody listened, the official says.
Poisonous Levels
Doctors from the Guangxi Institute of Occupational Disease Prevention and Treatment in Nanning came to the village early this decade and tested dozens of villagers, including Ms. Lai. Dozens were found with poisonous levels of heavy metals, and doctors gave them medicine they said would help clear the metals from their bodies. Ms. Lai says she took the treatment for months, but that the doctors told her that the metals failed to discharge from her body completely. She eventually stopped the treatment.
The government tore the factory down in 2004. The orange trees in the village are already growing better, she says, although her health problems have persisted.
Xia Cheng, the deputy director of the Nanning Environment Protection Bureau, says the agency cleaned much of the mine residue a decade ago. It advises farmers not to plant there, and pays them a small amount in compensation each year. Still, Mr. Xia says, villagers grow crops on contaminated land. “The land is owned by farmers,” he says. “We can’t go to cut the crops off.”
Lu Zuhua, an official with the agricultural service center in the town, says the vegetables grown near the factory site are used for food by the farmers and sold domestically.
Over the past five years, the Chinese government says it has increased its testing of food exports for heavy metals, but there are still gaps. “It’s very difficult for the authorities to check every batch,” says Chen Junshi of China’s Center for Disease Control and Prevention.
China’s soil is also compromised by waste from the thousands of private and public mines that dot the country. Last year, a group of Chinese scientists published a study that found the soil and vegetables around an abandoned lead and zinc mine a few hours outside of Shanghai was contaminated with heavy metals. It’s not clear when the mine was in operation, but the local environmental protection bureau says that historical records indicated it was in use during the Qing dynasty, which ended in 1911. Slag that the miners had excavated from the mountain was left in piles near farmland, allowing rain to wash the metals into nearby fields.
Chinese scientists tested samples of soil and vegetables, including cabbage, chrysanthemum and spinach grown in the area around the mine, near Shaoxing in Zhejiang province. The soil’s zinc level was 20 times higher, and cadmium levels 30 times higher, than the maximum heavy-metal concentrations allowed under China’s national soil-quality standards.
The authors of the study, which was published in February 2006 in the Netherlands-based scientific journal Environmental Geochemistry and Health, concluded that soil near the mine “was unsuitable for agricultural use.” Because of high levels of cadmium, lead and arsenic, the vegetables “could not be regarded as safe for human consumption,” they wrote.
Huang Wei, an official in the news office of the Zhejiang Provincial Environmental Protection Bureau in Hangzhou, says there have been no health problems or crop failures tied to soil contamination in the area, adding that residents haven’t lodged any complaints with local environmental officials. While metal pollution is a serious problem in theory, she says, the soil at the Shaoxing site would have to be tested further.
Heavy-metal residues stay in the soil — cadmium for decades, lead for tens of thousands of years — so fixing the existing problem won’t be easy. Chinese researchers at Zhejiang University in Hangzhou have teamed up with researchers from the University of Glasgow in Scotland to identify a cadmium-resistant rice strain, and they are exploring the process of genetically modifying crops to make them more resistant to absorbing metals.
Some of the farmers in Shaoxing have heard about the pollution, but believe the soil has improved as years have passed since the mine’s closure. “Before, our rice paddies didn’t grow very well,” says Xu Yingfu, the 58-year-old deputy head of Baojiashan village, who has grown rice, wheat, radishes and green vegetables for years. “The plants were small.”
Twice a year, Mr. Xu travels to a nearby town and sells his rice for around 10 cents a pound to wholesalers. One of the shops that buys rice from farmers and sells it to locals is Sunshine Grain & Edible Oil Center, in the nearby town of Shangyu. “Rich families buy rice from other provinces from northeastern China because it’s better quality,” says Ren Qingzhao, a 42-year-old shopkeeper at Sunshine Grain. “Poor families buy local rice.”
What the farmer Mr. Xu doesn’t sell, he and his family eat. At his home in Baojiashan village, which is a short walk from his fields, a bowl of rice that he grew sits in a strainer on the kitchen counter beneath turquoise cabinets. “This is for dinner tonight. It’s delicious,” he says. On this particular night, he plans on serving it with a fried mixture of green vegetables, pumpkin and pork.
Amid a global boom in commodity prices, a government-run company that owns the long-dormant mine now plans to reopen it. A notice in a local newspaper said that the mine would extract 30,000 metric tons of lead and zinc from the mountain annually. The notice invites the public to submit comments or suggestions by letter, fax or email.
There’s no evidence that contaminated crops from Shaoxing county are exported to the U.S. A local vegetable-processing company buys produce, including cabbage grown around the area; its frozen, vacuum-sealed packages are exported to countries including Japan and the U.S., according to Meng Louyun, an official at an agricultural service center in Shaoxing. But he says none of the vegetables come from farms near the old mine.
In the U.S., some public-health experts worry the government is not testing enough imported food for heavy metals. “It’s less stringent than Germany or Japan,” says Rufus Chaney, a research agronomist at the USDA. “It’s the luck of the draw, not preparation that’s protected us.”
-
–Ellen Zhu in Shanghai contributed to this article.
