According to the toxicity of metal ions, highly toxic metallic elements are: 13 species of mercury, uranium, indium, cadmium, thallium, arsenic, gold, vanadium, molybdenum, plating, silver, zinc, nickel.
Meanwhile, there are a total of 50 metal elements with poisoning and low toxicity. There are about 30 species of minerals which may produce harmful metallic dust. The elements are: cinnabar, black uranium ore, carnotite, pitchblende, Hui arsenic and cobalt mine, enargite, realgar, arsenopyrite, arsenic, cobalt ore, vanadium, lead, beryl, silicon beryllium stone, pentlandite, chromite, hematite, black tungsten ore and so on.
These metal powder is inhaled, can produce significant occupational disease, the majority of significant lesions on the lungs, can cause cancer, for example, containing hard ore of uranium, arsenic, nickel, chromium, cobalt metal powder , have more pronounced incidence of lung cancer. Containing arsenic trioxide metal powders standards, 50g/m3 from the past, to the 0.1g/m3. Free silica in the metal mineral dust and mineral mix, the majority of silicosis. Dust concentration limits, an increase of antimony, arsenic, chromium, uranium, nickel powder, and oil mist T, L, and V values may also be due to the toxicity of the dust, carcinogenic effects.
Other mine water pollution, mine water is not only the equipment corrosion damage, significant harm to the person, mine water is discharged to the surface, some flow directly into rivers, lakes, and some directly or indirectly seep into farmland, residents drinking water areas, orchards, etc.. In addition to the direct harm caused by acidic water, a lot of heavy nonferrous metals such as mercury, cadmium, lead, arsenic and radioactive elements. With the leakage of water four, directly or indirectly, for the plant or animal, absorption, and then transferred to the body, resulting in endless troubles. There is waste rock, ore dam, seepage to rivers, lakes, farmland, orchards, residential areas, etc., after the rain washing or scouring, which can cause the same harm, even if the mining production to stop, contain toxic heavy metals powder or acidic water will constantly continue to outflow or drainage from the level hole mouth, waste rock, ore dam and other places, so in a disused mine, there are still a legacy of the great sources of pollution.
Metal powder pathogenic, preventive measures for cancer, the first is to promote the leading cause of these problems in terms of attention to and strengthen the organization, management and scientific research work, and in the light of experience to take strong measures. Existing mines to prevent the hazards of silica dust measures, in addition to the degree of harm according to measure the ore containing free silica dust, but also according to the nature of the mineral dust to divide the hazard rating, which requires strengthening.
It is necessary to develop a unified standard of respiratory metal powder. When making development standards, it is necessary to consider the weight of the metal powder concentration, dispersion and free silica content. And nature of the mineral dust and the time that workers exposed to dust should also be taken into account. For different mines, its risk rating should be determined basing on the mineral dust’s toxic or carcinogenic metal elements. At the same time, the existing mine ventilation and dust removal equipment should be quickly studied and improved to achieve efficient, economical and suitable application.Source:http://www.mhcmp.com
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