Profile Toxicology Term Paper Example | Topics and Well Written Essays - 3250 words

Profile Toxicology - Term Paper Example Pb (23.5-27%), 207 Pb (20.5-23%) and 204 Pb (1.35-1.5 %).These isotopes are the stable decay product of three naturally radioactive elements : 206 Pb from Uranium, 207 Pb from actinium and 208Pb from thorium(Agency for Toxic Substances and Disease Registry (ATSDR), 2005) . Lead rarely exists as a metal, but rather, in combination with two or more elements to form Pd compounds. The element has three oxidation states (0 or the metal state, +2 and +4), the most common oxidative state being +2. Lead generally exhibits has amphoteric properties; +2 (basic) and +4 (acidic) (APHA, 1999). Lead is an element that naturally occurs in the earth’s crust. Ore deposits of Pb include galena (PBS), anglesite (PbSO4) and cerussite (PbCO3). Anthropogenic sources of Pb in the environment , include : homes (household dust, peeling of lead-based paints, toys, furniture, table ware etc.), contaminated food (food grown in Pb-contaminated soil or sprayed with Pb insecticides), soils and dust (flaking or weathering paint, improper renovation and disposal of building materials, roadside - contamination from leaded gasoline, settled dust from industrial sources), water (leaded pipes or connectors and lead- lined tanks), and air (industrial emissions from smelters, incinerators, manufacturing operations, recycling efforts, and leaded gasoline) (Davies, 1995). Historically, Pb was widely used in plumbing, as anti-knock agent in petrol, and as an addictive in paints. However, these uses have recently reduced due to environmental concerns about cumulative lead poisoning. Presently, Pb is used in storage batteries , paints, pigments and colored inks as shielding from radiation, e.g., in x-ray rooms and nuclear reactors. Lead is also used as cable covering, as ammunition, as electrodes, in solder and roofing material.(Martiez , Nagae , Zaia , & Zaia 2004). The fate and behavior of Pb in the environment is quite complex because of the many compounds of Pb and that can be found and the