Enviromental Science

• Pollution


  The contamination of the environment by humans adding any substance or energy
• Pollutant


  Any matter or energy introduced by human activities that harms resident populations thus altering community structure
• Common pollutants


  • Heavy metals
  • Gases
  • Oil
  • Sewage
  • Noise
  • Heat
  • Radiation
  • Pesticides
• Biological magnification


  The increase in concentration of a substance in successive members of a food chain
• Toxic substances


  May accumulate in members of higher trophic levels as a result of biomagnification
• Trophic transfer


  The movement of compounds (molecules) through trophic levels
• Water pollution


  Occurs when toxic substances enter water bodies such as oceans, lakes and rivers leading to the degradation of water quality and rendering it toxic to human health and the environment
• Domestic wastes


  • Wastes from houses and different commercial establishments that usually contain nitrates and phosphates
  • Sewage water carrying pathogens, other harmful bacteria, and chemicals that can cause serious health problems leading to diseases
• Industrial wastes


  • Large amounts of toxic chemicals
  • Untreated industrial waste discharged into water bodies
  • Industrial chemical wastes that can accumulate within the living tissues of aquatic organisms and threaten human health through the food chain
• Agricultural wastes


  • Fertilizers
  • Farm animal wastes
  • Sediments containing nitrates and phosphates that are carried away by water runoff resulting in eutrophication

  
• Eutrophication


  Enrichment of nutrients leading to the increase of algal population in a water body, thereby affecting the aquatic life

  
• Diseases from polluted water

  • Typhoid
  • Cholera
  • Hepatitis
  • Methemoglobinemia
• Air pollution


  Release of air pollutants in the atmosphere that can bring global effects and is harmful to human health
• Industrial air pollutants


  • CO, CO2, SO2, H2S
  • HF, F2, SiF4, H2(SiF6)
  • Hydrocarbons
  • Phosphate fertilizer manufacturing plants - fluorine compounds
  • Other chemical industries - hydrochloric acid, chlorine, oxides of nitrogen, Zn, Pb, As, oxides of Cu, and SO2, CO, and H2S
• Automobiles


  The most significant contributor to air pollution, releasing volatile organic compounds (benzene, toluene, and xylene)
• Burning of fuels


  Produces two-thirds of sulfur dioxide in the atmosphere, resulting in acid rain
• Sulfur dioxide (SO2)


  A colorless gas produced by combustion of fossil fuels at power plants and certain industrial sources, which goes along with nitrogen oxides to result in acid rain
• The impact of acid rain in Europe has been severe and is most noticed in forests of the northeastern US
• Agricultural activities contributing to air pollution

  • Burning of forest areas and grasslands to provide pastures and croplands for production
• Photochemical smog


  Usually occurs in urban areas and depends on primary pollutants as well as the formation of secondary pollutants
• Greenhouse effect


  A natural phenomenon that is enhanced due to elevated air pollutants
• Soil pollution


  The presence of pollutants or contaminants in soil, in high enough concentrations to pose a risk to human health and the environment
• Sources of soil pollution

  • Mining activities
  • Waste and sewage generation and disposal
  • Agricultural and livestock activities
• Agricultural wastes released into the environment pose a severe threat to the environment, affecting natural resources, crop productivity, and living organisms, including humans, and contaminating areas of land
• The long-term impacts of soil pollution on human health are still vague, but efforts through more research are still in progress to better understand the impacts of toxic pollutants

  
• Solid waste


  Discarded household and commercial waste, nonhazardous institutional and industrial waste, street sweepings, construction debris, agricultural waste, and other non-hazardous/non-toxic solid waste
• Hazardous waste


  Substances that are without any safe commercial, industrial, agricultural or economic usage and are shipped, transported or brought from the country or origin for dumping or disposal, and by-products, side-products, process residues, spent reaction media, contaminated plant or equipment or other substances from manufacturing operations and as consumer discards of manufactured products which present unreasonable risk and/or injury to health and safety and to the environment
• Developing countries have used more hazardous waste for production and consumption (chemicals and materials) than in developed countries, and most industries in developing countries use outdated and banned technologies that operate poorly and produce hazardous wastes
• Annually, there are 400 million metric tons of hazardous waste produced globally
• Minamata disaster


  An epidemic of an unknown disease of the central nervous system caused by the release of mercury (methylmercury) from the Chisso Corporation into Minamata Bay, Japan in the 1950s, which contaminated fish and shellfish