Dangerous Properties of Materials Coursework Example | Topics and Well Written Essays - 1000 words

Dangerous Properties of Materials - Coursework Example Though all forms of mercury can cause effects in the central and peripheral nervous system, methyl mercury and metallic mercury are more harmful. Acute inhalation of metallic mercury vapours may cause damage to the lungs, nausea, diarrhea, increased blood pressure, skin rashes, eye irritation, chest pains, stomatitis, gingivitis, cough, dyspnea and salivation. Chronic exposure to high levels of metallic, inorganic, or organic mercury may cause permanent damage to brain, kidneys and developing fetus. Effects of chronic exposure on brain functioning may cause weakness, fatigue, weight loss, vision or hearing disorders, tremors development, behavioral changes, aneuploidy in lymphocytes of the exposed, dremographia and memory loss. Chronic exposure to mercuric compounds is sometimes also characterized by anorexia, apathy, fever, diaphoresis, photophobia, insomnia and scaling or peeling of the skin of the hands and feet with bullous lesions. Toxicity Metabolites and Biomarkers Exposure to organo-mercury compounds is indicated by chemical analysis of blood mercury. Inorganic mercury concentrations in blood can be used to determine acute exposure to high dose of mercury. Absorption of phenyl mercury through gastrointestinal tract with even acute exposure resulted in a marked increase in blood concentrations as well as urinary excretion of mercury. Chemical analysis of urinary mercury can alternatively be used to determine exposure to chronic, low and moderate inorganic mercury forms. As mercury can deposit on hair from surface contamination, hair mercury is a good indicator of exposure to methyl mercury. Dose The acute lethal dose for inorganic mercury compounds is 1 to 4 grams or 14 to 57 milligrams per kilogram body weight for a 70 kg adult person. The acute lethal dose ranges from 20 to 60 milligrams per kilogram body weight of methyl mercury for a 70 kg adult person. According to EPA, a limit of 2 parts of mercury per billion parts of drinking water (2 ppb) is saf e for human health. A limit of 1 part of methyl mercury in a million parts of seafood (1 ppm) has been set by the Food and Drug Administration. The Occupational Safety and Health Administration (OSHA) has suggested a maximum permissible limit of 0.1 milligram of organic mercury per cubic meter of workplace air (0.1 mg/m3) and 0.05 mg/m3 of metallic mercury vapor for 8-hour shifts and 40-hour work. Effects on the environment, cases and their treatment Mercury (Hg) is a naturally occurring odorless liquid metal with shiny, silver-white appearance. Mercury also combines with other elements to form several inorganic salts and organo-mercury compounds. It enters the environment naturally from rocks, soil, volcanic activity, and by vaporization from the oceans. However, two-third of the Mercury entering the atmosphere every year is released from human sources. These sources include coal-burning power plants, chemical manufacturing plants, waste incinerators and mining of ore deposits. The disease caused by exposure to mercury compounds is called Mercury poisoning, Hydrargyria or Mercurialism. The first case of mercury poisoning was witnessed among researchers at St Bartholomew’s Hospital in 1865. Two of the three technicians died because of excessive exposure to methyl mercury while manufacturing organic mercurial compounds. Human exposure to high levels of