Construction - Lead dangers
Overexposure to lead is one of the most common over exposures found in industry. Lead overexposure is a pimary cause of workplace illness. Therefore, Government has established the reduction of lead exposure to be a high strategic priority. Government's five year strategic plan sets a performance goal of a 15% reduction in the average severity of lead exposure or employee blood lead levels in selected industries and workplaces.
In general populations lead may be present at dangerous concentrations in food, water, and air. Sources include paint, urban dust, and folk remedies. It is also a major potential public health risk. Lead poisoning is the leading environmentally induced illness in children. At greatest risk are children under the age of six because they are undergoing rapid neurological and physical development.
Lead is commonly added to industrial paints because of its characteristic to resist corrosion. Industries with mainly high potential exposures include: construction work involving welding, cutting, brazing, blasting, etc., on lead paint surfaces; most smelter operations either as a trace contaminant or as a major product; secondary lead smelters where lead is recovered from batteries; radiator repair shops; and firing ranges. Oral ingestion may represent a major route of exposure in contaminated workplaces. Most exposures occur with inorganic lead. Organic (tetraethyl and tetramethyl) lead, which was added to gasoline up until the late 1970s, is not commonly encountered. Organic forms may be absorbed through the skin, while inorganic forms can not.
Inorganic lead is not metabolized, but is directly absorbed, distributed and excreted. The rate depends on its chemical and physical form and on the physiological characteristics of the exposed person (e.g. nutritional status and age). Once in the blood, lead is distributed primarily among three compartments – blood, soft tissue (kidney, bone marrow, liver, and brain) and mineralizing tissue (bones and teeth). Absorption via the GI track following ingestion is highly dependent upon presence of levels of calcium, iron, fats and proteins.
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