Unit-2 Environmental Pollution and Health: Definition of Pollution

Environmental Pollution and Health

• Pollution is the accumulation and adverse interaction of contaminants within the environment, occurring on or within land, oceans, or the atmosphere.
• Contaminants can be chemical compounds, biological entities, particulate matter, or energy, and can be of natural or anthropogenic origin.

Sources of Environmental Pollution

• Environmental pollution can be hazardous for all living beings, leading to multiple diseases, such as skin, nose, and throat irritation, wheezing, coughing, respiratory concerns, etc.

Impacts on Human Health

• Air pollution, water pollution, thermal pollution, and radioactive pollution can have severe impacts on human health.

Air Pollution

• Air pollution is the presence of unwanted substances in the ambient atmosphere, generally resulting from human activities.
• Sources of air pollution include:
  • Natural sources: volcanoes, pollen grains, forest fires, dust storms, biogenic (plant emits hydrocarbons)
  • Anthropogenic sources: human activities, industrial emissions, vehicle emissions
• Types of air pollution:
  • London smog (reducing smog or sulfurous smog): high concentration of SO2 in the air
  • Los Angeles Smog (oxidizing smog or photochemical smog): air contains NO2 and hydrocarbons, and mixture is exposed to sunlight

Water Pollution

• Water pollution is any contamination of water with chemicals or other foreign substances that are detrimental to human, plant, or animal health.
• Major sources of water pollution include:
  • Human settlements
  • Industrial activities
  • Agricultural activities
• Facts about water pollution:
  • 2 million tonnes of human waste are disposed of into water bodies
  • 1.8 billion people in the world drink faecal-contaminated water
  • 70% of industrial waste in developing countries is dumped untreated into water
• Major water pollutants:
  • Sediments: excessive amount of soil particles carried by flowing water
  • Oxygen-demanding wastes: organic wastes (animal manure, plant debris, etc.) decomposition by bacteria leads to oxygen depletion
  • Infectious microorganisms: parasitic worms, virus, bacteria from infected organisms and human
  • Organic compounds: carbon-containing synthetic chemicals from industries, cleaning agents, etc.

Noise Pollution

• Noise pollution has a significant impact on wildlife, as they are more dependent on sound for survival.
• Effects of noise pollution on wildlife:
  • Animals develop a better sense of hearing than humans
  • Noise pollution can cause aggressive behavior in pets and wildlife

Thermal Pollution

• Thermal pollution is a sudden increase or decrease in temperature of any natural body of water caused by human activity.
• Major causes of thermal pollution:
  • Factories/plants taking in water from natural sources and putting it back with altered temperature
  • Deforestation: exposing water to direct sunlight
  • Run-off from hot surfaces (e.g., roads falling into waterbodies)
  • Volcanoes/geochemical activity under the ocean that trigger warm lava to raise the temperature of water
• Impacts of thermal pollution:
  • Decrease in levels of dissolved oxygen: suffocate species and cause mass killing
  • Loss of biodiversity: some species can’t tolerate higher temperature
  • Alien species could migrate into the area: alteration of food-web

Radioactive Pollution

• Radioactive pollution is the deposition or introduction of radioactive substances into the environment, where their presence is unintended, or the levels of radioactivity are undesirable.
• Impacts of radioactive pollution:
  • Harmful to life due to the emission of ionizing radiation
  • Potent enough to cause damage to tissues and DNA in genes