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China’s tainted rice trail

Gong Jing

Readinch

One tenth of China’s rice yield may carry harmful levels of cadmium, writes Gong Jing in this report on heavy metals in the food chain, winner of the “biggest impact” category at the 2012 China Environmental Press Awards.

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Gong Jing’s article on cadmium-contaminated rice – which reflects the seriousness of China's food-safety crisis – was originally published in Caixin’s flagship magazine, Century Weekly, on February 14, 2011. We translated it and reposted it on chinadialogue in three parts last April.

This week, the report won the “biggest impact” category at the 2012 China Environmental Press Awards, organised bychinadialogueThe Guardian and Sina, with the support of the SEE Foundation. In recognition of this achievement, we are republishing the first part of the article here.

Eighty-four year old Li Wenxiang pulled a small bag of rice out from under a paint-stained table. The grains were white, plump and slightly translucent – to the naked eye, no different from any other rice. But tests have shown the levels of cadmium in this rice far exceed permitted limits. The locals call it “cadmium rice”.

Cadmium is a heavy metal, listed in 48th place on the periodic table. In nature, it is found as a compound in ores, but in the human body, it can cause serious harm.

Li believes the rice may be the cause of the strange condition afflicting him. Although in good health otherwise, Li has not been able to walk properly for 20 years. He cannot manage 100 metres without feeling unbearable pains in his feet and calves.

Doctors have not been able to come up with a diagnosis, so Li just calls it “soft-foot disease”. He said that, here in the village of Side in Guangxi province, south China, more than a dozen elderly people suffer similar symptoms.

Li has been eating the local rice for 28 years, ever since he returned to the village for retirement in 1982. Research papers by a number of academics have shown that the village’s farmland was polluted by cadmium before even the 1960s and, as a result, levels of the substance in the rice grown here are far above those permitted by the state.

Cadmium is often found where zinc, lead and copper are mined. As a result of the heating and leaching processes these ores are subjected to, cadmium is released into the waste-water. If the mine is not properly managed, the water then carries the cadmium into the surrounding soil. Research by experts at the US Department of Agriculture shows that, of all major crops, rice is second only to lettuce in its ability to absorb cadmium.

Other research has indicated that cadmium accumulates in the liver and kidneys, and is not naturally expelled from the body. After years, or even decades, of gradual accumulation, the body will start to show signs of cadmium poisoning. Most commonly, this affects liver function and bone health – resulting in a range of skeletal changes.

In Japan in the 1960s, hundreds of people living in the Jinzu River basin in Toyama Prefecture were affected by skeletal pain. Mining had left local fields heavily polluted with cadmium and, after years eating rice grown on the land, farmers were suffering from cadmium poisoning. Those affected complained of stabbing pains in their bones, and the disease came to be known as “ouch-ouch sickness”. The symptoms are very similar to Li Wenxiang’s “soft-foot” condition, and researchers have pointed out that many other villagers in Side have health problems similar to those seen in the early stages of “ouch-ouch”.

Cadmium is not the only heavy metal found at high levels in rice in China. The country has struggled with a food-supply pollution chain for many years: China’s rapid industrialisation has resulted in widespread mining and heavy metals such as cadmium, arsenic and mercury, once locked in compounds underground, being released. Via water and the air, these have polluted a significant proportion of China’s land, from where they enter crops and, subsequently, human beings.

On a visit to Side in December 2010, villagers privately confirmed that a number of residents were suffering pains all over their body. One person who married into the village in the early 1980s said that, back then, girls from other villages didn’t want to marry men from Side as they were scared they would have “soft-boned” children. That turned out to be an exaggeration, but there are still concerns.

The villagers said that, before China’s grain markets were liberalised, state-owned granaries used to refuse their crops: “Your village’s rice is poisoned,” the officials told them. But the inhabitants of Side have no option but to eat this “poisoned” rice that the government would not accept.

In mid-winter, the fields were littered with the stalks left over from harvesting, while vegetables grew green and lush alongside. But appearances can be deceptive: the 1,000 mu (0.7 square kilometre) Dadong Field is in bad shape. Tests in 1986 found soil cadmium levels of up to 7.79 milligrams per kilogram – 26 times the permitted level.

A 1986 study by Lin Bingying, a professor at Guilin University of Technology, found that cadmium levels in young rice plants in the village were three times the acceptable limit, set by central government, of 0.2 milligrams per kilogram, while mature plants were five times over the limit, reaching 1.005 milligrams per kilogram.

An environmental-protection official with the local agricultural bureau said that, to date, there has been little improvement. One senior agricultural expert said that cadmium pollution is largely irreversible – once the soil is contaminated, levels of cadmium in crops will remain constant for years.

The water in the paddy fields comes from Side River, which was polluted by a zinc and lead mine 15 kilometres upstream. The mine is small and, when first established by the county in the 1950s, had no environmental-protection measures in place – cadmium-contaminated water was even used to irrigate the villagers’ fields. Over 5,000 mu (3.3 square kilometres) of farmland was contaminated by the mine, with Datong Field the worst affected. Subsequent research found that waste-water from the mine contained 194 times the level of cadmium permitted in water used for irrigation.  

The mine isn’t very profitable and has been shut down for various periods over the decades. Currently, it is in private hands. None of the villagers know for sure if the “poison” from the rice has entered their bodies and, if it has, what will happen. The majority of them are unable to prove the pains they suffer are even due to an illness, much less any link with the rice.

In 2002, the quality monitoring centre for rice and rice products at China’s Ministry of Agriculture carried out safety checks on samples of rice available on the market nationwide. The results indicated that the most widespread problem was lead contamination, with 28.4% of samples breaching limits. Second was cadmium, at 10.3%.

Five years later, in 2007, Pan Genxing, professor at Nanjing Agricultural University’s Institute of Resources, Ecosystem and Environment of Agriculture, led a study which purchased 91 samples of rice from markets at the county level or higher in six regions across China. The results were similar – 10% of rice on the market had excessive levels of cadmium.

Their study was published in the journal Safety and Environment, but unfortunately even this did not attract much attention. Many academics have argued that, as there normally aren’t any restrictions on planting rice on polluted land, a figure of 10% of rice containing excessive cadmium is a realistic one for China today.

Rice is the staple food for 65% of China’s people, and the country produces almost 200 million tonnes of the crop each year – so 10% represents about 20 million tonnes. Pan Genxing’s research also indicates that heavy-metal pollution mainly affects the southern long-grained rice variety, with provinces such as Hunan and Jiangxi particularly badly hit. In April 2008, Pan’s team purchased 63 samples of rice from markets in provinces including Jiangxi, Hunan and Guangdong – and 60% were found to breach national standards for cadmium levels. One reason for this is that the hybrid rice used in southern acidic soils absorbs more than normal rice.

Chen Tongbin is a researcher at the Chinese Academy of Science’s Institute of Geographic Sciences and Natural Resources Research. For years he has studied soil pollution and restoration. According to Chen, heavy-metal pollution in northern China exists in scattered patches, but in the south the problem is more common, and in parts of Hunan, Jiangxi, Yunnan and Guangxi, affects wide swaths of land.

Chen disagrees with the common belief that one fifth of China’s arable land is polluted by heavy metals. He said a figure of one tenth is more likely, based on studies of wide areas of land in several provinces carried out over a number of years. Cadmium and arsenic pollution are the most common problem, he said, with each present in about 40% of polluted land.   

If Chen’s estimate is accurate, 120,000 square kilometres of China’s total 1.2 million square kilometres of arable land is contaminated with pollutants like cadmium and arsenic. Around 54,000 square kilometres of land may be polluted with cadmium alone.

Most of these polluted areas are still growing rice, most farmers are still eating their own crops and rice contaminated with heavy metals is still reaching the market. There is nothing to protect the Chinese people from this threat.
 

This article first appeared in Century Weekly, where Gong Jing is a reporter.
 
NEXT: Tracing the sources of cadmium pollution

Part three: Fixing the problem 

Homepage image from Greenpeace

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对现有毒大米的解决办法?

本文最后都在介绍专家们忙于防止如何生产出更多毒大米,那对市场中已经流通着的毒大米(中国年产稻米近2亿吨,10%即达每年2000万吨啊),如何教老百姓用最简单的办法鉴别随时可能流入家门的毒大米、政府如何监测、回收和处置已有的毒大米、如何防止这些进入市场的毒大米再次进入某些行业的供应链(比如食品加工、养殖、饲料等待),以及这些已有的毒大米可能对普通人群的健康影响是什么,是否也有专家正在研究了呢?如果都没有或几乎没有这样的专家,作者应该建议政府对现有的毒大米做些什么(除了做“根”上的污染防治之外)?

Any solutions for existing contaminated rice?

At the end, the article introduces how experts are trying to prevent further contaminated rice from being produced. But what about poisoned rice that's already on the market (China produces close to 2 million tons per year, or 10% of the 20 million tons)? How can we impart to regular people a simple way to distinguish contaminated rice, and how can we prevent the contaminated rice already in circulation from entering various industry supply chains (processed foods, seed cultivation, fodder, etc.)? Moreover, are researchers looking into the effects from contaminated rice on the health of ordinary people? If there are no or not enough researchers looking into this subject, what should this author be entreating the government to do (aside from doing the "basics" to prevent pollution)?


一个全球性的问题

    文末写道,“中国百姓的健康,在被重金属污染的稻米之前几不设防。”
    我认为,这句话在世界范围内也适用。
    华侨遍居海外,很多人经营中餐馆,偏爱购买使用产自祖国的大米。因此,镉超标的大米走上全球华人的餐桌,还波及很多经常吃中餐的西方人(比如我)。
    镉超标的大米不仅是中国的问题,也是世界的问题。
    公平地讲,我们必须承认还有一个本文没有提及的镉污染源:燃煤发电。燃煤废气污染是镉污染的主要来源。中国被列为燃煤废气污染的罪魁祸首,某些所谓的发达国家(包括美国)同样有这个问题。
    如果继续将煤作为主要能源,全球污染必将加剧。

A Global Problem

The article states, "There is nothing to protect the Chinese people from this threat."

I would say this statement applies to the world at large also.

With the diaspora of Chinese people (华侨) living overseas, a great many of them operating Asian restaurants abroad, they have a preference for purchasing and consuming rice imported from mother China. In turn, the cadmium-laden rice escapes China and is consumed by Chinese people across the world, and those Westerners (like me) who love to eat Chinese food on a regular basis.

The cadmium-laden rice is not only a China problem, but a world problem, too.

In all "fairness" to China, we must recognize yet another source of cadmium pollution not mentioned in the article: coal power plant combustion. While China is labeled as the main world culprit in airborne coal waste pollution, other so-called developed countries (the USA included) pollute the environment with coal combustion emissions, which are a main source of cadmium pollution in the environment.

If we continue the use of coal as a main source of power, the toxins problem will intensify across the globe.


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