Cadmium is a toxic metal found in nature with low concentrations, was discovered in 1917, but from 1930 will be used for the amount significantly. Cadmium in the world output is 18000 to 25000 tonnes / year. In the cadmium ore is always made up of a pair of tin devil, because if the tin needed in trace cells, the cadmium does not have a biological benefits are known. Cadmium has many applications in areas such as photoconductor, semiconductors, batteries, vacuum tubes, X-ray screens and flashing screens. These compounds are also used in foundry technology, power, manufacturing the mirror, in the field of lubricants, and chemical analysis can also be used in the veterinary field by fungicidal properties and kills the worms and in catalysis. They are also used in welding rods and welding rods particularly in aluminum.
Due to the numerous applications which had only recovered 10% Cadmium was used also largely escape into the environment, including dirt and slag while up to 30% of the metal. When people are added to the amount of waste released from the combustion of fossil fuels up to 5000 tonnes / year, the number of natural drainage becomes unimportant, even insignificant.
Here we should remembering the waste ore (in addition to the mine tailings in the electronic form righteous extraction process) is the main source of waste of chemical industry. Waste may be the largest integrated phosphate Cadmium contaminated with varying amounts depending on the geographical origin. In USA, for example, phosphate industry in 1988 has produced 204 million tons of liquid waste. We can notice the overload of Cadmium of ecosystems and the oceans. Moreover, due to the dwindling areas rich ore, the mines have increasingly poor and create more waste than for the same 1 heavy metals ore will increase in our environment a strong strong and continuous.
Cadmium into ecosystems from various sources:
• the dust, processing waste water as lead, tin, iron, steel, ...
• water washing in the casting industry power.
• when the tire wear cars, in this case, the promotion Cadmium in nature vulcanised and diesel fuel.
• in phosphate, including Cadmium is impurities.
• in the sludge of water purification stations.
it is estimated that the total Cadmium poured into the ocean of up to 8000 tons / year which half is derived from human activities. It is not known the evolution of Cadmium in the oceans will look like. Finally Cadmium and its compounds are included in the black list of banned conventions Always don the discharge of toxic substances into the sea.
But Cadmium also in the atmosphere of a chocolate factory (eg battery factory) . Occupational exposure to the substance is especially dangerous when it is in the form of smoke. Here it is worth noting that smokers inhale more Cadmium. One cigarette contains metal 1.5-2g and addicts inhale 10% of this amount. Smoking a pack of cigarettes a day will double the amount of Cadmium enters the body.
Cadmium accumulates in the human body and survive very long. It is usually located in the liver and kidneys. A long-term exposure to small concentrations of this metal is likely to lead to emphysema evidence, lung disease and kidney disorders.
1946 a syndrome characterized by skeletal deformities, muscle pain, easy fractures and kidney disorders are diagnosed in older women, multiple births, has attracted the attention of the medical community in the district of Toyoma Funchu Japan. They called Itai-Itai disease is (or painful disease). This syndrome has killed hundreds of people. The researchers found that the patients in absorbing Cadmium about 600g rice every day by eating contaminated by river water Jintsu, rivers polluted by ore and slag from a processing plant Cadmium. People with albuminuria and proteinuria disease is caused by exposure to cadmium is not less than 20 years. The track of the people who work in occupations exposed to cadmium says it was this chronic diseases. For men, the Cadmium is toxic to the kidneys and its effects are cumulative and silently. Further toxicity of Cadmium causes calcium metabolism disorders, affecting the bones and joints, causing joint pain, bone pain even cause osteoporosis. High levels of cadmium in drinking water also causes hypertension in rats. Cadmium also is a carcinogen and teratogen in rodents. 1965 Cadmium is also suspected to have caused prostate cancer in workers in a battery factory in the UK.
Using
đang được dịch, vui lòng đợi..