Cadmium is mainly produced in zinc mine, lead-zinc mine and copper-lead-zinc mine. When roasting the ore and extracting it by wet method, cadmium is released into waste water and waste residue. If the mining process and tailings management are improper, cadmium mainly enters the soil and farmland through water sources. According to the research of experts from the United States Department of Agriculture, rice is the main cereal crop with the strongest cadmium absorption, and its cadmium content is second only to lettuce.
Previous studies have shown that cadmium is mainly accumulated in the liver and kidney and will not disappear naturally. After years or even decades of chronic accumulation, the human body will have obvious symptoms of cadmium poisoning. The most common way of cadmium poisoning is to damage renal function, which will hinder the growth and metabolism of human bones, thus causing various pathological changes of bones. In the 1960s, hundreds of people were affected by the pain of osteopathy in Kawaguchi, a prodigy in Toyama Prefecture, Japan.
Researchers such as Liu Zhanqi from Taiyuan Institute of Environmental Medicine, China Institute of Radiation Protection, investigated 260 cadmium contacts in a lead-zinc mine polluted area in China for more than 20 years around 2000. Among them, bone mineral density of 84 contacts was lower than normal, and most of them complained of inexplicable pain. Among the 22 most serious contacts, 19 had osteoporosis and softening in different degrees.
Some scholars' preliminary research shows that in some lead-zinc mining areas in southern China, the high incidence and mortality of cancer are closely related to the cadmium content in the soil and the rice with excessive cadmium. A painful disease
Old Li Man Wen Xiang suspected that his strange disease was related to this rice. The old man is still in good health, but he has been unable to walk well for more than 20 years. As long as you don't walk more than 100 meters, your feet and calves will be sore. The doctor couldn't make a definite diagnosis, so the old man simply named himself-limp foot disease. He told this reporter that in Sidi Village, Xingping Town, Yangshuo County, Guangxi, where he lives, more than a dozen other elderly people have similar symptoms. Li Wenxiang has been eating rice produced in his village for 28 years since he retired to his village in 1982. Many scholars' research papers confirmed that the cultivated soil in this village had been polluted by heavy metal cadmium as early as 1960s. Correspondingly, the cadmium content of the produced rice is also seriously exceeding the standard.
Medical literature has proved that cadmium will cause diseases such as bone pain after many years, and even lead to terrible "pain disease" in severe cases. The so-called "pain syndrome", also known as osteopathy, was named in Japan in the 1960s. Because of mining in this country, cadmium seriously pollutes farmland, and farmers eat rice and other foods on polluted soil for a long time, which leads to cadmium poisoning. The patient's bone is as painful as a needle, and he often cries "pain, pain", hence the name. The symptoms of this disease are very similar to those of limp feet mentioned by Wen Xiang, an old Li Man. Many scholars also pointed out that many villagers in Sidi Village have initial symptoms of suspected "pain".
Soft foot disease
Qin Guixiu, 7 1 year old, is another "soft-footed" old man in Sidi Village. In the last four or five years, her legs have been weak and have no strength. It hurts when she walks. Besides, her waist often hurts. She went to a big hospital in Guilin and was diagnosed as "bone calcification". The specific cause, the doctor said not clearly. She said that more than a dozen people in this village have such symptoms, and maybe 50 people have them. However, a village cadre in this village does not agree with her statement, thinking that low back pain is very common in rural areas, and such statistics are meaningless. This cadre can't explain why so many people have the same symptoms. In fact, many soil scholars in China mentioned Sicun anonymously in their papers and public lectures, saying that many villagers in the village had the initial symptoms of "painful illness"; There has been a phenomenon in the village that "chickens give birth to soft eggs and newborn calves suffer from rickets". Some scholars have revised this statement. They believe that it is more accurate to say that some villagers have the initial symptoms of suspected "pain". The embarrassment of scholars is that so far no official or medical unit has confirmed what the above symptoms are.
From 20 10 to 12, many villagers privately confirmed that many people in the village were suffering. A villager who married from a foreign village in the early 1980s said that at that time, girls from other villages were unwilling to marry in their own village, saying that the children born would be "losers". After getting married, she found this statement a bit exaggerated, but people's worries have not been eliminated so far. The villagers confirmed that the state-owned grain depot had exempted the village's public grain before the grain was fully liberalized. The official who collected the grain said, "The rice in your village is poisonous." The biggest difference between the villagers in this village and those in other villages is that they can only eat "poisonous" rice that the country does not want.
Similar cases are not limited to Side Village in Guangxi. In fact, in many places, there are serious urinary cadmium exceeding the standard and corresponding symptoms.
In particular, it is worth mentioning that about 10% of rice in China has the problem of cadmium exceeding the standard, whether it is the spot check of agricultural departments or the research of scholars in recent years. This is undoubtedly a heavy reality for the country with the largest rice consumption in the world.