Heavy metal cadmium contaminated soil invades rice, market 10% rice cadmium exceeded

From under a dappled table under the paint, the 84-year-old Lee Wen-tzu pulled out a small bag of rice. The color is pure white, slightly translucent, full of particles, and the naked eye can't see any difference in these rice.

However, after testing, the cadmium content of this rice was seriously exceeded. The locals referred to this rice as "cadmium rice."

Cadmium, a heavy metal, is ranked 48th in the periodic table of chemical elements. In nature, it exists as a compound in minerals and it is extremely harmful after entering the human body.

The old man Li Wenjue suspected that his strange disease was related to this kind of rice. The elderly body is still tough, but he has not been able to walk for more than 20 years. As long as you take no more than 100 meters, your feet and legs will feel sore.

The doctor couldn't diagnose it. The old man simply named himself - a soft foot. He told the reporter that in the village of Sisi, Xingping Town, Yangshuo County, Guangxi, another dozen old people have similar symptoms.

After retiring from the village in 1982, Li Wendi has been eating rice produced in this village for 28 years. A number of scholars' research papers confirmed that the cultivated soil of the village had been contaminated by heavy metal cadmium as early as the 1960s; accordingly, the cadmium content of the rice produced was also seriously exceeded.

The medical literature has proved that cadmium enters the body and can cause bone pain and embolism after many years, and it can cause terrible “painful illness” when severe. The so-called "painful disease", also known as bone pain, was named Japan in the 1960s. The country has caused cadmium to seriously pollute farmland due to mining. Farmers have long eaten foods such as rice on contaminated soil, which leads to cadmium poisoning. The bones of patients suffer from severe needle pain. The mouth often shouts “painful pain”, so it is named. The symptoms of the disease are very similar to those of Li Wenyu's old foot. Many scholars also pointed out directly that many villagers in Sisi Village already had initial symptoms of suspected “painful illness”.

Similar cases do not only appear in the village of Sisi, Guangxi. In fact, there are crowds of urinary cadmium and other serious excesses and corresponding symptoms in many places.

In particular, it is worth mentioning that no matter whether the spot checks conducted by the agricultural sector in recent years or scholars' studies have shown that about 10% of rice in China has cadmium exceeding the standard. This is undoubtedly a heavy reality for countries with the largest rice consumption in the world.

In addition to cadmium, there are other problems with excessive levels of heavy metals in rice. Researchers at the Institute of Geochemistry at the Chinese Academy of Sciences said that the main channel for inland residents to consume methylmercury is rice, not fish. As we all know, methylmercury is one of the leading culprits of poliomyelitis.

A complete food contamination chain has continued for many years. In the process of rapid industrialization in China, mining and other mining activities have caused the release of harmful heavy metals such as cadmium, arsenic, and mercury that originally existed in the form of compounds into the natural world. These harmful heavy metals contaminated a large part of China’s land through water and air, contaminating rice and then entering the human body.

Tens of millions of contaminated rice farmers are the biggest victims. Rice is the absolute staple food for the three meals a day. Some peasants know that there is pollution, but they are trapped in the price difference between selling rice and buying rice, and they are forced to eat contaminated rice. More farmers do not know that the rice they eat is toxic. They are not even sure what the heavy metals are.

What is more serious is that China has almost no specifications for the cultivation of land contaminated by heavy metals, and a large number of contaminated land is still producing normal rice.

Moreover, most of the polluted rice produced on the contaminated land can be freely listed and circulated freely. This has led to the exposure of urban and rural residents outside the polluted rice-producing areas, but the extent of the danger is still limited. There is currently a lack of research.

The village soil doctors in Sisi County mentioned the village of Guilin Si without name in their dissertations and lectures. They claimed that many villagers had the initial symptoms of suspected "painful illness" and that "chicken under the soft eggs, newborn calves Cartilage

71-year-old Qin Guixiu is another village with a "soft foot" disease. In the past four or five years, she always had weak legs, no power, and she was in pain when she walked. In addition, her waist often hurts. She once went to a major hospital in Guilin for treatment and was diagnosed with "bone calcification." The specific cause, the doctor said it was not clear.

She said that there are more than a dozen people in this village with such symptoms, and perhaps 50 people have it. However, one village cadre in the village did not agree with her. He believed that rural people suffer from back pain and back pain. This statistic does not make sense. The cadre also failed to explain why so many people had the same symptoms.

In fact, a number of domestic soil scientists mentioned the village of Si without name in their dissertations and public lectures. They claimed that many villagers in the village had already had initial symptoms of “painful illness”; the village’s “soft eggs under the chickens” Newborn calves suffer from osteomalacia".

The journalist sought confirmation from some of the scholars. The scholars amended the above statement. In their opinion, a more accurate statement is that some villagers have suspected initial symptoms of “painful illness”. The trick for scholars is that so far no official or medical unit has confirmed the symptoms.

In December 2010, when a journalist from the journal visited the village in Sisi, many villagers confirmed in private that there were indeed many people in the village who were in pain. A villager who was married from an outside village in the early 1980s said that the girls in the village were unwilling to marry into this village and said that a born child would be a "cartilage head." She married and found that this statement is a bit exaggerated, but people's concerns have not been eliminated.

The villagers confirmed that before the grain was fully released, the state grain bank had waived the grain of the village. Official officials of the grain collection said: “The rice in your village is poisonous.” The biggest difference between the villagers in this village and other villages is that they can only eat such “toxic” rice that the country does not want.

In the harsh winter, the arable land outside the village is full of rice husks left after rice is harvested, and some vegetables grow green and pleasant. However, the nearly 1,000 mu of cultivated land known as Da Putian was indeed “sick”: actual measurement data in 1986 showed that the content of available cadmium in the above-mentioned land was as high as 7.79 mg/kg, which was 26 times the national allowable value.

According to a study by Lin Bingying, a professor at Guangxi Guilin Institute of Technology, in the village, in 1986, the cadmium content of early rice was 3 times that of the national allowable value of 0.2 mg/kg, and late rice was more than five times the specified value. 1.005 mg/kg.

A person in charge of the Agricultural Environmental Protection Station of Yangshuo County Agriculture Bureau told the reporter that the situation of heavy metals in the land has not improved much. A senior agricultural expert said that the cadmium pollution is quite irreversible and once the soil is contaminated, even after many years of production, the cadmium content of the crops produced will only change slightly.

The source of rice paddies is the river of Sisi, which flows through the village, and the source of pollution is a lead-zinc mine that is 15 kilometers away from the village. This small-scale mine was mined as a state-owned ore mine in the county since the 1950s. At that time, there was almost no environmental protection facility. Waste water containing cadmium flowed into the villagers' arable land as irrigation water.

According to statistics, a total of more than 5,000 acres of land were contaminated by the mine, and Dabutian was the most serious of the 1,000 acres. Later studies have shown that the amount of cadmium in the early mine wastewater exceeds 194 times that of agricultural irrigation.

The efficiency of this lead-zinc mine is not good. It has been closed for several decades and has now been transferred to private hands. At the same time, no villagers knew exactly whether these "poisons" from rice had entered their bodies and what had happened after entering. Most people cannot prove that the body's pain is a disease, and it is even more difficult to confirm its relevance to rice.

10% rice cadmium exceeded Nanjing Agricultural University Pan Genxing's team randomly purchased samples from multiple county-level and above markets across the country. The results showed that about 10% of the commercial rice cadmium exceeded the standards of cadmium contamination, not just the rice in the village.

In 2002, the Ministry of Agriculture's Rice Quality and Quality Supervision, Inspection and Testing Center conducted a random inspection of rice on the national market. The results show that the most serious heavy metal in the rice is lead, with a rate of 28.4%, followed by cadmium, with a rate of 10.3%.

Five years later, in 2007, Professor Pan Genxing and his research team at the Institute of Agricultural Resources and Ecological Environment of Nanjing Agricultural University (hereinafter referred to as Nanjing Agricultural University) were in six regions of the country (East, Northeast, Central, Southwest, and South China). In northern China, 91 samples of rice were randomly purchased from the county-level and above markets. The results also showed that about 10% of the commercial rice cadmium exceeded the standard.

Their research was later published in the magazine "Safety and Environment." Unfortunately, such important research has not attracted much attention.

Many scholars told this reporter that based on the vast majority of unconstrained rice cultivation in contaminated rice fields, 10% of cadmium exceeds the standard rice, which basically reflects the current reality in China.

China produces nearly 200 million tons of rice each year, 10% of which is 20 million tons. Such a huge number is enough to illustrate the seriousness of the problem. Pan Genxing's research also showed that heavy metal pollution in rice in China is dominated by barley in the south, especially in Hunan and Jiangxi provinces. In April 2008, Pan also led his research team to randomly sample 63 farmer's markets in Jiangxi, Hunan, and Guangdong provinces. The experimental results confirmed that more than 60% of the cadmium content in rice exceeded the national limit. One of the important reasons why the value is so high is that cultivars of super hybrid rice in the southern acid soil absorb cadmium more easily than conventional rice. However, the problem of cadmium contamination in rice in southern provinces is still extremely serious.

Pan Genxing told the journalist that the serious situation of rice pollution in China cannot be fundamentally changed in the short term.

Researcher Chen Tongbin, director of the Center for Environmental Restoration at the Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, has devoted many years to research on soil pollution and restoration. He told this correspondent that China’s heavy metal pollution is only scattered in the north, but it is more dense in the south, and there are some contiguous distributions in parts of Hunan, Jiangxi, Yunnan, and Guangxi provinces.

Chen Tongbin has objections to the widespread claim that one-fifth of China's arable land is contaminated by heavy metals. According to a large-scale survey conducted in some provinces and cities for many years, he estimated that heavy metal pollution is more likely to account for about 10%. Among them, the ratio of cadmium pollution and arsenic pollution is the largest, accounting for about 40% of the contaminated farmland.

If Chen Tongbin’s estimate is true, based on China’s 1.8 billion mu of cultivated land, nearly 180 million acres of land will be contaminated with cadmium, arsenic, etc., and only cadmium-contaminated land may reach about 80 million mu.

What makes people feel heavy is that most of these polluted areas are still growing rice, and the farmers are mainly eating their own rice. Not only that, rice polluted by heavy metals also flowed to the market. The health of the Chinese people is not fortified before being contaminated by heavy metals.

Tracking cadmium pollution in Xinma Village, Zhuzhou, Hunan, Dabaoshan, Guangdong and other regions, rice was seriously contaminated in Xinma Village, Zhuzhou City, Hunan Province, which is more than 2,000 kilometers away from Guangxi Sisi Village. In January 2006, a nationwide cadmium pollution incident occurred. Two people died. 150 villagers were judged as chronic mild cadmium poisoning after physical examination. On September 11th of that year, the Hunan Provincial Government announced the survey results and believed that the village’s drinking water and groundwater were not contaminated by cadmium, but the arable soil was contaminated by cadmium, and the heavy metals in the rice were seriously exceeded.

In January 2011, this reporter once again came to this village in Majiahe Town, Tianyuan District, Zhuzhou City. More than a thousand acres of land in the village and adjacent villages have been declared abandoned by the local government. The villagers still believe that the discharge of cadmium-containing wastewater from the original motorcycle accessories factory in the village was the most direct cause of cadmium poisoning among villagers. However, the government’s cadmium pollution has also been considered an important reason by the villagers.

The local government has not yet officially announced the cadmium content of rice in the village. Professor Pan Genxing from Nanjing Agricultural University’s Agricultural Research Institute and his team once asked the villagers in the village for two laboratory tests of the original rice in April 2008. The results showed that the cadmium content was 0.52 mg/kg and 0.53 mg/kg, respectively. It is 2.5 times the national standard.

The cadmium pollution in cultivated land in Xinma Village of Zhuzhou mainly comes from the Xiangjiang River, which is 1 km away. The Xiangjiang River is the most heavily polluted river in China. Xiawan Industrial Zone, a few kilometers upstream of Xinma Village, is one of the major sources of heavy metal pollution in the Xiangjiang River.

Around several industrial zones in Zhuzhou City, dozens of square kilometers of farmland were contaminated with heavy metals. The villagers of Xinqiao Village, located at the edge of the Xiawan Industrial Zone, confirmed to the reporter that thousands of acres of land in the villages of Xinqiao, Xiawan and Jianshe were contaminated by heavy metal wastewater discharged from Xiawan Industrial Zone as early as the 1980s. The local government has subsidized 800 pounds of rice per acre of rice fields every year for more than 20 years.

In the Zhuzhou and Xiangtan sections of the Xiangjiang River, there are a large number of land on the two banks directly irrigated by the Xiang River water. In theory, they are highly likely to be contaminated, but the research and figures in this area are relatively scarce. Wang Xiangxiang, deputy director of the Xiangtan City Environmental Protection Association, once invested in the detection of soil and rice pollution in Yantang Village, Yisuhe Town, Xiangtan County. As a result, both the soil cadmium content and the cadmium content of rice were seriously exceeded.

Before and after the sampling of Xinma Village in 2008, Pan Genxing and his entourage also went to the remaining cadmium-contaminated areas widely reported by the media for rice sampling. These places include Dabaoshan in Guangdong, Bailutang in Zhangzhou, Hunan and Dagu Piaotang in Jiangxi. Through experiments, rice in these areas has been seriously polluted, with a cadmium content of at least 0.4 mg/kg and a high of 1.0 mg/kg, which is generally 2 to 5 times the national limit.

The Devil Industrial Revolution No. 48 released the devil of cadmium, and rice is the most potent cereal crop that absorbs most of the cadmium. In recent decades, the cadmium-like rice in Sisi Village and Xinma Village has been “toxic” and there are numerous villages in China. Staged. For China, where more than 65% of the population uses rice as a staple food, such stories do not make people feel relaxed.

Cadmium is a white, shiny, heavy metal, chemical symbol Cd, atomic number 48. It originally existed as a compound and did not interact with human life. The industrial revolution released this devil. According to foreign studies, there are 22,000 tons of cadmium in the soil each year.

Cadmium is mainly associated with zinc ore, lead-zinc ore, and copper-lead-zinc ore. Cadmium is released into the wastewater slag when the above ore is calcined and wet ore is extracted. If the mining process and tailings are not properly managed, cadmium will enter the soil and farmland mainly through water sources. An expert from the U.S. Department of Agriculture showed that rice is the most important cereal crop that absorbs cadmium, and its grain cadmium level is second only to lettuce.

Studies have shown that cadmium accumulates primarily in the liver and kidneys and does not disappear naturally. After years of chronic accumulation, the body will experience significant symptoms of cadmium poisoning. The most common path of cadmium poisoning is that it damages kidney function, leading to the obstruction of growth and metabolism of the human bones, thereby causing various bone lesions. In the 60s of the last century, bone-ache patients in the Shentongchuan Valley of Toyama Prefecture in Japan affected hundreds of people.

Researchers at the China Institute for Radiation Protection Research Institute, Taiyuan Institute of Environmental Medicine Liu Zhanqi and other researchers had investigated 260 people with lead-zinc ore contamination in China for more than 20 years before and after 2000. Of these, 84 were found to have a lower than normal bone density. Most of them complained of inexplicable pain in the body, and 19 of the 22 most severe contacts experienced varying degrees of osteoporosis and softening.

More scholars' preliminary studies have shown that in some regions of lead-zinc mines in southern China, there is an inseparable relationship between high rates of human cancer and death rates and soil cadmium content and excessive cadmium in rice.

In addition to cadmium, other heavy metals are also eroding rice fields and rice in China.

For example, the Feng Xinbin team of the Institute of Geochemistry of the Chinese Academy of Sciences took several mercury-contaminated areas in Guizhou as an example. In the September 2010 issue of the “Environmental Health Outlook” magazine, the paper stated that the main channels for inland residents to ingest meth It is rice, not fish; Zhang Junhui of Zhejiang University analyzed the PhD dissertation in 2009. Among 9 natural villages with dismantling history of e-waste in Taizhou, Zhejiang, 7 of them were affected by different levels of cadmium, copper, and zinc. Pollution; The 2008 study by the Li Yonghua team of the Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, showed that the lead and arsenic contamination of rice in Xiangxi lead-zinc mine area in Hunan Province is serious.

Heavy metal cadmium is invading rice through contaminated soils; a sample survey by scholars shows that about 10% of rice cadmium exceeds the standard in China's multi-land market; China is not fortified before a variety of heavy metal-contaminated rice, “New Century” weekly journalist Gong Jing system Magnifier understands Rice is "toxic" but it is still eaten for many years. A villager said: “There is money to spend money, and there is no money for life”

In the face of rice contaminated with heavy metals, people often do nothing. When interviewed by Xinqiao Village near Xinma Village in Zhuzhou, the reporter found that the villagers knew that rice was “toxic” but still consumed for a long time. One villager said he was helpless. She said: "If you have money, you have money, and if you don't have money, you have a fate."

The reality of a southern rural village that the villager tells us is that each person only has a few fields and the land is only enough to produce grain for export. If you sell polluted rice and buy net rice, the larger price difference will push up their cost of living.

Many scholars pointed out that China's current land-to-household system, as well as basic conditions such as the self-sufficiency of farmers' rations, have exponentially amplified the problem of heavy metal pollution in rice.

Pan Genxing believes that in western countries, land is private, and agricultural land is mainly planted by farmers and large companies. Once part of the land is contaminated by heavy metals, farmers or large companies will soon choose to abandon their crops or adjust their crops for the sake of overall interests. In contrast, individuals in China’s peasants are unable to cope with the pollution and can only choose to passively bear it.

Scholars said that Western countries attach more importance to the negative externalities of corporate economic behavior than China, and generally require companies to pay environmental protection funds to the government. This fund can, in most cases, deal with environmental issues including soil pollution. The lack of such institutional arrangements by the Chinese government objectively encourages the emergence of negative externalities of the environment.

In addition, the government's customary blockade of soil pollution information has led to serious information asymmetry between the officials and the people. More cultivators have consumed heavy metals in excess of standard rice when they do not know or know very little.

The unique dietary habits also lead to more prominent heavy metal pollution in China. Rice is not the absolute staple food in most western countries, but 65% of Chinese people use rice as their absolute staple food. Some scholars have calculated that even if rice reaches the national limit of cadmium content of 0.2 mg/kg, the total daily intake of cadmium in southern China also exceeds the limit recommended by the World Health Organization.

The cadmium rice is not forbidden. If there is a large amount of heavy metals that exceed the standard rice, as long as it is allowed to grow, it is inevitable that people will be victimized with the reality that there is little or no supervision. The heavy metal exceeds the standard rice and enjoys people's horrible “freedom”.

Except for being stopped in a few places because of extreme pollution incidents, most of the owners of contaminated soil are cultivators, and they are all free to choose the type of crops to be grown, including rice. The villagers of Sisi Village in Guangxi and Xinqiao Village in Hunan did not receive any ban on planting from the government.

In addition, except for a small amount of heavy metals that are out of standard rice that are circulated on the market, government departments often do not give advice to villagers and citizens about how to avoid eating contaminated rice.

In fact, heavy metal over-standard rice is completely free to circulate in reality. The rice in Sicun Village and Xinma Village has not been forbidden to be sold by the government. Therefore, although most of the rice is eaten by the villagers, there is still a considerable amount of polluted rice flowing freely to the market.

In recent years, due to the country’s increased efforts in the food safety system, it is difficult for heavy metal over-standard rice to appear in large-scale supermarkets in large and medium-sized cities. However, polluting rice remains unpredictable in farmers' markets in counties and cities and townships.

In February 2008, Sichuan Chengdu Quality and Technical Supervision Bureau detected the rice cadmium produced by Handan Ruitai Rice Industry Co., Ltd. and Sichuan Wenjun Rice Industry Co., Ltd. during the sampling inspection of food safety, and requested the two companies to rectify. According to China's current food quality management regulations, it is illegal for the two companies to produce and sell cadmium-excessive rice, and the punishment is justified.

However, the two companies expressed their grievances: First, when companies purchase rice, they purchased the rice in line with the principle of acquisition. Because of the complex acquisition channels of middlemen, it was impossible to judge which area contained cadmium, which could not be controlled from the raw materials purchased. Second, cadmium Exceeding the standard and the company's production process does not matter, should be related to the cadmium in the soil.

The more general view of scholars is that on the one hand, the government does not prohibit heavy metals from exceeding the standard at the source, that is, it allows rice to be planted on contaminated soil. On the other hand, it prohibits heavy metals from exceeding the standards in circulation. This is self-contradictory, in reality, It is also difficult to implement.

One fact that is not optimistic is that if there are a large number of heavy metals that exceed the standard rice, they will inevitably be eaten by people and will inevitably suffer as long as they are allowed to grow.

It is generally believed that the amount of heavy metals that exceed the standard of distribution to the city is only a minority. Because of the constant replacement of the varieties of rice consumed, even if the citizens eat heavy metals that exceed the standard, the harm is small.

However, Chen Tongbin and his colleagues observed for many years that as rural residents in soil-contaminated areas have become increasingly affluent and have increased health awareness, they tend to sell heavy metals that exceed the standard rice to the city and replace them with clean rice. Therefore, urban residents suffer from heavy metal poisoning. Risks are also increasing.

In 2006, Wang Xiangxiang, deputy director of the Xiangtan City Environmental Protection Association, collected 500 samples of urine from residents of Xiangtan River near the Zhuzhou city of Xiangtan, and a medical institution in Changsha cooperated with it to detect a scary result: 30% of human urine The liquid cadmium exceeded the standard, and 10% of people required professional treatment according to the national occupational disease prevention and control standards. Due to various restrictions, Wang failed to carry out more tests. Some researchers believe that those people who exceed the cadmium concentration in Xiangtan, in addition to drinking water from the Xiang River, can hardly say that there is no impact of excessive cadmium on rice because cadmium rice has also been purchased in the Xiangtan market.

Regardless of the willingness of officials and the public, many scholars believe that there is a trend worth noting that in the future of China's agricultural product safety issues, heavy metal pollution will replace pesticides and become an accident-prone area.