Mining Metal use and refining

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4.8 Mining

– Mineral Metal Extraction Mining of coal, metal ores and other minerals is undertaken extensively around the world. Historically mine workers have suffered higher incidences of ill health than workers in other heavy industry sectors. Coal mining has long been associated with the dust induced lung disease Pneumoconiosis and other illnesses such as work related Emphysema. Mining activities can present particular hazards to health from various substances. These may be from the mineral being extracted or may be present as undesirable by-productscontaminants. The main health hazard is exposure to dust in various forms. Asbestos is still mined in a number of countries around the world, it is also found in trace quantities in deposits of other minerals such as talc. The hazards of asbestos are presented in a separate section of this manual. Arsenic is present in metal deposits such as tin and copper. It may be encountered as an undesirable component during mining and processing but is also produced commercially as a by-product of the refining. Arsenic is toxic and can kill if large doses are either consumed or inhaled. Silica is present in many minerals and particularly in stone extraction Mining can also present a range of physical hazards such as noise, vibration, radiation, heat stress, damphumidity and changes in atmospheric pressure.

4.9 Metal use and refining

Many hard metals are present in small amounts within our bodies as essential elements and form an important part of our function. However if exposure to large quantities occurs then significant ill health effects can result. 50 Cadmium use has been restricted due to its toxicity, however it is still used within the aviation industry as an anticorrosive coating, and in NiCad batteries. The physiological effects of excessive cadmium exposure can be separated into two distinct categories as follows; the acute effects include nausea, vomiting and severe gastro-intestinal disturbances whilst chronic effects range from fatigue and emphysema to liver and kidney damage. In severe cases of acute poisoning, for example after flame-cutting of cadmium plated bolts, death can quickly follow from a chemical pneumonia. Chromium is a steel-grey, hard metal element, which will take on a high lustre. Its high melting point, 1900 o C, together with its inert nature makes the metal useful as an alloying material and for electro-plating. It has a number of radioactive isotopes, which have found use in medicine. It is capable of having a number of valent states and the range of salts reflects this i.e. chromous, chromic and chromyl. Some have irritant properties similar to chromium trioxide chromic acid causing dermal irritation, ulceration and allergic dermatitis. Inhalation will also cause primary irritation, nasal septum perforation, pulmonary irritation whilst carcinoma has also been associated with exposure to chromate salts. Lead is a soft malleable metal with good anticorrosive properties. It has been used extensively in the construction industry as well as in the production of batteries, bullets and weights. It has also been mixed with other metals to form useful alloys such as tinlead solder. Its various compounds are toxic and can be inhaled, ingested or absorbed through the skin. Acute effects are rare, as lead is mainly a cumulative chronic poison, but some organo lead compounds [such as that used in leaded gasoline] can be quickly absorbed through the skin and affect the brain causing death in some cases. Chronic effects are observed with the slow accumulation of inorganic lead in the body, often being deposited in the bones and being latter released if a trauma occurs. Chronic effects range from stomach pains to lethargy and anaemia, ultimately causing death. It can give rise to brain damage especially to the young and unborn. 51 5 ASSESSMENT OF HEALTH RISKS

5.1 Introduction