MHE513 - Risk Assessment and Epidemiology Module 2 - Case Essay

MHE513 - Risk Assessment and Epidemiology Module 2 - Case - Essay Example The Public Health Statement of Agency for Toxic Substances and Disease Registry (ATSDR, 2005) provides information about zinc, including the hazards associated with excessive exposure to the otherwise essential element. Zinc is a ubiquitous element of the earth’s crust, occurring in small amounts in almost all igneous rocks. It is widely distributed in air, water, soil, and all living matter. Zinc enters the environment both through natural processes and human activities, in particular activities such as mining, purification of zinc, lead and cadmium-containing ores, steel production, and coal and waste burning. Increased levels of zinc in the soil can occur through disposal of wastes from metal manufacturing industries and electrical utilities producing coal ash, and fertilizer application. Industrial and domestic sewage and run-off from soil containing zinc can release zinc into waterways and ground water. Zinc, present as fine dust particles in the air, is washed down by rain and snow into the lakes and rivers where it mostly settles on the bottom. A small amount of zinc may occur dissolved in water. The concentration of dissolved zinc increases with increasing acidity of water. Zinc and its compounds have many industrial uses including galvanization of iron and steel to prevent rusting and corrosion; preparation of alloys such as brass and copper; manufacturing of dry cell batteries, white paints, ceramics, rubber, fabric dyes and wood preserving compounds. Zinc is also an important constituent of cosmetics, hair-care and health-care products such as sunblock lotions, talcum powder, anti-dandruff shampoos, diaper rash ointments, deodorants etc. Zinc chloride is used to make smoke bombs. Zinc carbamates are used as pesticides (World Health Organization WHO, 1996). Exposure of humans to metals is generally inevitable as metals are ubiquitous in the environment. Chemicals including zinc are released into the environment (air, water