Sludge Watch ==> China - sewage spreading contributes heavy metals to food
Maureen Reilly
maureen.reilly at sympatico.ca
Sun Jul 29 01:12:06 EDT 2007
Sludgewatch Admin:
In this story there is a discussion about how China has heavy metal
contaminated farmland - some of it contaminated from sewage sludge. Sewage
sludge carries a burden of heavy metals from industries that discharge into
sewers as well as consumer products that contain metals.
Odd to see Rufus Chaney of USDA - long time defender of agricultural
spreading of heavy metal contaminated sewage sludge - saying the public
isn't protected from contaminated food from China when his life's work is
supporting contaminated sewage spreading on food lands in North America.
...........................................
China Faces a New Worry: Heavy Metals in the Food
Studies Warn of Produce Grown in Hot Spot Soil; Pingyangs 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.
Chinas 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 countrys
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 countrys food come from the soil in which it is
grown. So far it hasnt 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.
Chinas 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 countrys arable land, is contaminated by
pollution.
Mounting Concerns
Concerns are mounting internationally as China plays a growing role in the
global food industry. The countrys exports currently account for about 12%
of global trade in fruits and vegetables. Chinas 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 whats going on outside our borders, says
Michael Bolger, chief of the Chemical Hazard Assessment Team at the FDAs
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.
Chinas 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.
Chinas 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 Chinas 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
Pingyangs 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 cant 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. Its
very difficult for the authorities to check every batch, says Chen Junshi
of Chinas Center for Disease Control and Prevention.
Chinas 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. Its 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 soils zinc level was 20 times higher, and cadmium
levels 30 times higher, than the maximum heavy-metal concentrations allowed
under Chinas 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 havent 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 wont 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 mines closure.
Before, our rice paddies didnt 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 its better quality, says Ren Qingzhao, a
42-year-old shopkeeper at Sunshine Grain. Poor families buy local rice.
What the farmer Mr. Xu doesnt 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. Its 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.
Theres 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. Its less stringent than Germany or
Japan, says Rufus Chaney, a research agronomist at the USDA. Its the luck
of the draw, not preparation thats protected us.
Ellen Zhu in Shanghai contributed to this article
http://cornucopia.org/china-faces-a-new-worry-heavy-metals-in-the-food/
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