For example, Minamata disease in Japan is caused by the transformation of mercury in wastewater discharged from caustic soda manufacturing industry into organic mercury through biological action; Another example is pain, which is caused by cadmium discharged from zinc smelting industry and cadmium electroplating industry.
Lead emitted by automobile exhaust enters the environment through atmospheric diffusion and other processes, which leads to a significant increase in the current surface lead concentration, which makes the absorption of lead by modern people increase by about 100 times compared with that of primitive people, which is harmful to human health. Heavy metals do great harm to human body.
Heavy metals generally exist widely in nature in natural concentration, but due to the increasing mining, smelting, processing and commercial manufacturing activities of heavy metals, lead, mercury, cadmium, cobalt and other heavy metals enter the atmosphere, water and soil, causing serious environmental pollution. ?
Extended data:
Heavy metal pollution mainly comes from industrial pollution, followed by traffic pollution and domestic garbage pollution. Industrial pollution is mostly discharged into the environment through waste residue, waste water and waste gas, which is enriched in people, animals and plants, thus causing great harm to the environment and human health.
The treatment of industrial pollution can reduce its pollution through some technical methods and management measures, and finally reach the national pollutant discharge standard; Traffic pollution is mainly automobile exhaust emissions, and the state has formulated a series of management measures.
For example: using ethanol gasoline and installing automobile exhaust purifier. Domestic pollution is mainly caused by some domestic garbage, such as waste batteries, broken lamps, unused cosmetics, glazed plates and so on. As long as the heavy metal pollution is controlled from the source, it can be reduced more or less.
Experts pointed out that at present, the backward research and development of technology, equipment and technology in China's plastic production enterprises is the main cause of serious pollution, while poor management, local protection and people's weak awareness of environmental protection have aggravated the pollution and need to be strengthened. Production enterprises should look to the future, advocate environmental protection and use environmentally friendly additives to make the PVC industry develop healthily and in the long run.
References:
Baidu encyclopedia-heavy metal pollution