How to avoid the harm of cadmium poisoning, we all know that excessive heavy metals will do harm to human body. Cadmium poisoning is mostly chronic, and food damage caused by short-term exposure to excessive cadmium will not appear immediately. Chronic cadmium poisoning is most likely to damage renal function and liver function. Understand how to avoid the harm of cadmium poisoning.
How to avoid the harm of cadmium poisoning 1 elemental cadmium cannot exist stably in nature, and mainly exists in hexacadmium mine and zinc mine. Since the beginning of the 20th century, cadmium and its compounds have been widely used in nickel-cadmium batteries, pigments, alloys, electroplating, plastic products and other manufacturing links, and the output and usage of cadmium are increasing. According to statistics, the world releases about 30,000 tons of cadmium into the environment every year, of which 82%-94% will enter the soil. Long-term exposure to rice, vegetables, fruits and drinking water with excessive cadmium pollution will lead to chronic cadmium poisoning.
Among them, rice is the most seriously polluted by cadmium. Rice is the staple food of more than 60% of the population in China, and now the heavy metal pollution of rice is gradually emerging. It is reported that about 65,438+00% of the rice in many markets in China exceeds the standard.
Cadmium poisoning is mostly chronic, and short-term exposure to foods with excessive cadmium will not appear immediately. Generally, the biological half-life of cadmium entering human body is as long as 10 to 30 years. During this period, cadmium intake will mainly accumulate in the liver and kidneys. After several years or even decades of chronic accumulation, the human body will have obvious symptoms of cadmium poisoning.
It can cause irritation of digestive tract mucosa, with symptoms such as nausea, vomiting, diarrhea, abdominal pain and convulsion. This chronic cadmium poisoning caused by absorption through the digestive tract is most likely to damage organs such as kidney, spleen and liver, and also cause anemia and decreased reproductive function. Long-term intake of food contaminated with cadmium will make cadmium accumulate in the body, leading to systemic osteomalacia and pain, which is called "pain".
To prevent and control cadmium, we must do the following two things:
(1) Eat less crustaceans, shellfish and cephalopods. Because these seafood have a strong ability to enrich cadmium, especially shellfish and cephalopods such as scallops, scorpions and squid, coastal residents like it very much, and some people want to eat it almost every other day. Please don't be greedy for these diners who like delicious seafood, and it is best not to exceed 180 grams per person per week.
(2) Do not smoke. The cadmium content in most tobacco leaves is high, and the cadmium intake of smokers is much higher than that of non-smokers. Long-term smoking is harmful to the lungs and kidneys.
How to avoid the harm of cadmium poisoning 2 internationally, cadmium is listed as food pollutants and human carcinogens, and China has also clearly stipulated the emission targets of cadmium. The harm of cadmium to human body mainly includes:
1. Even if the cadmium content in the human body does not exceed the standard, the absorbed cadmium will have a half-life of ten or even thirty years in the human body. Long-term consumption of food containing cadmium may cause chronic kidney poisoning, affect our immune system, and may also cause rickets.
2. Excessive absorption of cadmium will lead to acute poisoning, nausea, retching, diarrhea and other symptoms, and may also cause central nervous system poisoning and even death.
Articles containing cadmium:
Cheap metal ornaments contain a lot of cadmium, such as hair ornaments and earrings, which may be absorbed by the human body when worn. Even if it is thrown away, it will do harm to the environment and pollute water and soil. Therefore, it is necessary to buy qualified jewelry to reduce cadmium exposure. The soil in some provinces of China has been polluted by cadmium, and the crops, vegetables and animals they grow all contain cadmium.
Preventive measures for cadmium poisoning;
1. Don't buy or wear poor quality metal ornaments.
2. Don't eat food containing cadmium.
3, cadmium poisoning phenomenon, should immediately go to the hospital for examination and treatment.
4. Workers working in cadmium-containing environment should wear gas masks.
How to avoid the harm of cadmium poisoning 3. The main sources of cadmium how to reduce cadmium intake?
Where does cadmium harmful to human health mainly come from?
Generally, there are two sources of cadmium in human body: one is rice; The second is tobacco. Experts explained that China's "Hygienic Standard for the Limit of Cadmium in Food" stipulates that the cadmium content in rice is ≤0.2 mg/kg, in flour ≤0. 1 mg/kg, in meat and fish ≤0. 1 mg/kg, and in eggs ≤0.05 mg/kg.
According to the recommendation of the expert committee issued by the World Health Organization 1972, people's daily tolerance for cadmium intake from food is 1mg/kg, which is five times that of China's rice cadmium standard. The data show that the cadmium content in aquatic products and animal kidneys is much higher than that in rice, and people with these two food preferences will be at greater risk.
Smoking is the main way to inhale cadmium. Nearly half of cadmium in smoke will be inhaled by human body, and eventually about 30% will be absorbed by human body, which is 6 times that of digestive tract. At least 2 micrograms of cadmium in each pack of cigarettes will be absorbed by the human body. Tobacco is as rich in cadmium as rice.
The intake of cigarettes made from tobacco grown in cadmium contaminated soil will increase exponentially. In addition, be careful not to store acidic foods in cadmium-plated containers. Ladies who love beauty should also be reminded that although cadmium does not penetrate well into the skin, wearing bracelets, necklaces and other inferior accessories containing cadmium for a long time is also harmful to the health.
We can take a comprehensive approach to reduce cadmium intake.
1. Eat more foods containing zinc: It is found that if foods containing cadmium contain zinc, the absorption of cadmium can be reduced, so eating more foods containing high zinc such as seafood, beans, melon seeds, meat and eggs can reduce the absorption of cadmium.
2. Don't smoke: Tobacco and rice can also enrich cadmium, and smoking is another way to ingest cadmium. If you often smoke cigarettes made from tobacco grown in cadmium-contaminated soil, your cadmium intake will increase greatly. About 30% of cadmium in smoke will be absorbed by human body.
2. Rice is the main cereal crop with the strongest cadmium absorption.
In recent decades, stories about "toxic" cadmium rice in Sidi Village and Xinma Village have been staged in countless villages in China. For China, where more than 65% of the population lives on rice, such a story is not relaxing.
Cadmium is a silvery white lustrous heavy metal with chemical symbol Cd and atomic number 48. It originally existed in the form of compounds, and there was no intersection with human life. Industry unleashed the devil. Studies abroad estimate that 22,000 tons of cadmium enter the soil every year in the world.
Cadmium mainly coexists with zinc ore, lead-zinc ore and copper-lead-zinc ore. 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.
Besides cadmium, other heavy metals are also eroding paddy fields and rice in China.
For example, Feng Xinbin's team from Institute of Geochemistry, Chinese Academy of Sciences published a paper in the American magazine Environmental Health Outlook on September 20 10, saying that the main channel for inland residents in China to ingest methylmercury, the chief culprit of Minamata disease, is rice, not fish; According to the doctoral thesis of Zhang Jun Society of Zhejiang University in 2009, seven of the nine natural villages with a history of dismantling electronic waste in Taizhou, Zhejiang Province were polluted by cadmium, copper and zinc to varying degrees. The research of Li Yonghua team of Institute of Geographical Sciences and Resources of Chinese Academy of Sciences in 2008 showed that the lead and arsenic pollution of rice in lead-zinc mine area of Xiangxi, Hunan Province was serious.
3. How harmful is cadmium exceeding the standard to human body?
Cadmium is a heavy metal, which will do harm to human bones and kidneys for a long time and is one of the most harmful elements to human health. There is almost no cadmium in newborns, and almost all cadmium in human body is accumulated from food and environment after birth. Cadmium, as a heavy metal, originally exists in the form of compounds and has no intersection with human life. But industry unleashed the devil. Studies abroad estimate that 22,000 tons of cadmium enter the soil every year in the world.
However, in the process of rapid industrialization in China, harmful heavy metals such as cadmium, arsenic and mercury, which originally existed in the form of compounds, were released into nature. These harmful heavy metals have polluted a considerable part of land in China through water and air, and then polluted rice, and then entered the human body.
Obviously, cadmium exists widely in people's lives. Any element in the human body that exceeds the standard will have more or less influence. Because most scholars who study metal elements don't know medicine, most doctors only know potassium, sodium, calcium and magnesium on the list of trace elements, but little about cadmium.
According to the research data of Japanese scientists, if a small amount of cadmium is ingested every day, 50 years later, 10% people will have renal dysfunction such as proteinuria. Chronic cadmium poisoning is most likely to damage renal function and liver function. Almost all chronic diseases in China, such as hypertension, chronic obstructive pulmonary disease, diabetes, anemia, osteoporosis, tumors and so on. It may be related to excessive cadmium in food.
Fourth, the toxicity of cadmium has cumulative effect.
"Long-term exposure to large doses of cadmium will do harm to human tissues and organs in many ways." Experts said that cadmium is absorbed by the human body, forms cadmium sulfur protein, reaches the whole body through blood, and selectively accumulates in kidneys and livers. "The kidney can accumulate and absorb 1/3, which is the target organ of cadmium poisoning."
According to experts, the initial symptoms of chronic cadmium poisoning are fatigue, headache, dizziness, atrophy of nasal mucosa, cough, stomachache and weight loss. After the development of the disease, patients will have symptoms such as waist and knee pain, yellow cadmium ring on teeth, systemic bone pain, osteoporosis, increased tingling during activities, and even minor trauma can cause fractures. Some severe patients also have emphysema, decreased respiratory function, renal insufficiency, kidney calculi, urinary protein, liver injury, anemia and so on.
It is worth noting that even if cadmium rice is eaten several times, it will not be poisoned immediately. Because the health hazards caused by cadmium pollution will take a long time to appear, and there is a lag in time. "That is to say, the toxic accumulation of cadmium has a long-term impact on the human body. Even if you stop eating high-cadmium rice, the damage to health will continue. This is especially necessary for farmers who grow their own rice in cadmium-polluted areas and eat their own rice, as well as urban residents who have been eating high-cadmium rice. "