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Contaminants in Soil and Water. Heavy Metals and Pesticides. Heavy Metals. Metallic chemical elements that are toxic at low concentrations Mercury (Hg) Cadmium (Cd) Arsenic (As) Chromium (Cr) Lead ( Pb ) Uranium (U). Mercury Poisoning. Environmental Source:
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Contaminants in Soil and Water Heavy Metals and Pesticides
Heavy Metals Metallic chemical elements that are toxic at low concentrations • Mercury (Hg) • Cadmium (Cd) • Arsenic (As) • Chromium (Cr) • Lead (Pb) • Uranium (U)
Mercury Poisoning Environmental Source: • Consumption of seafood with mercury in the flesh (bio-accumulation) • Inhaling contaminated air from coal power plants Human Health Impacts: • Peeling skin, hair and teeth loss, memory impairment
Mad Hatter disease Skin peeling from fingertips
Arsenic Poisoning Environmental Source • Contaminated groundwater • Natural arsenic leaches into water • byproduct of oil extraction • Food grown in contaminated soil • Rice in the USA can have arsenic levels of 260 parts per billion Human Health Impacts • Scaling skin, Headaches/confusion, hair loss, convulsions, lung/skin cancers
Lead Poisoning Environmental Source • Lead in household items • Paint, gasoline, pipes, pesticides in soil, batteries Human Health Impacts • Cognitive deficits, kidney failure, reproductive problems, memory loss, depression
Pesticides DDT • Dichlorodiphenyltrichloroethane
DDT Developed to kill insects responsible for spreading diseases like malaria (WWII) • Chemist who developed DDT won Nobel Prize in Medicine 1948 • Post-war used as insecticide on farms, at home, in residential urban areas
DDT Health Impacts Listed as a Toxic chemical • Poisonous to wide range of animals, not just intended target “pests” In humans: • Linked to diabetes • Birth defects • Developmental problems in children • Parkinson’s disease • Possibly carcinogenic (causes cancer)
DDT Safety Symbol Symbol for “Environmental Pollutant” listed by European Chemicals Agency
Rachel Carson “Silent Spring” • Written in 1962, first account of the far-reaching dangers of DDT • Huge backlash from chemical industry • Led to DDT being banned in USA, 1972