Environmental Pollution

Pollution: Definition & Pollutants

  • Pollution = undesirable alteration of air/land/water harming life.
  • Pollutants = solid, liquid, gaseous, heat, radiation, sound agents causing harm.

Classification of Pollutants

  • Degradable/non-persistent → naturally broken (dead matter, sewage).
  • Slowly degradable/persistent → remain long (pesticides, rubber).
  • Non-degradable → not broken (lead, mercury, nuclear waste).

Types of Pollution

Air, Water, Soil, Marine, Noise, Thermal, Nuclear hazards.

Air Pollution

Primary Pollutants

CO, CO<em>2CO<em>2, NO</em>xNO</em>x, SOxSO_x, volatile organic compounds, suspended particulates.

Secondary Pollutants

Formed in air: H<em>2SO</em>4H<em>2SO</em>4, HNO<em>3HNO<em>3, H</em>2CO3H</em>2CO_3, photochemical smog.

Effects

  • Human: respiratory diseases; CO toxic at 0.001%0.001\%.
  • Plants: leaf injury, growth loss.
  • Materials: paint & monument corrosion.
  • Ozone layer: depleted by CFCs.

Control

Filters, precipitators, tall stacks, cleaner fuels, proper siting, CPCB standards.

Air (Prevention & Control) Act 19811981 – key terms

Air pollutant, air pollution, approved appliance, chimney, control equipment, emission, industrial plant.

Water Pollution

Water Resource Facts

  • Earth water cover 71%71\%.
  • Freshwater 3%3\% (ice 2.997%2.997\%, usable 0.003%0.003\%).
  • Human body water 70%70\%.

Sources

Point (identifiable outlets) vs. Non-point (runoff, acid rain).

Major Pollutants/Causes

  1. Pathogens (coliforms).
  2. Oxygen-depleting wastes → fish kill.
  3. Nutrients (nitrates, phosphates) → eutrophication.
  4. Excess fertilizers & pesticides → bio-magnification.
  5. Toxic inorganics (acids, salts, PbPb, HgHg).
  6. Sediments from erosion.
  7. Oil spills/runoff.

Groundwater Pollution Causes

Urban runoff, improper industrial storage, agrochemicals, leaking tanks, faulty septic systems, mining/arsenic.

Control Measures

Effluent treatment, wetland/root-zone purification, source-level legal limits.

Water (Prevention & Control) Act 19741974 – key terms

Pollution, sewage effluent, sewer, stream, trade effluent.

Noise Pollution

  • Noise = unwanted sound; non-accumulative but harmful.
  • Sources: industry, traffic, religious venues, loud electronics.