Section 9.5

Impacts of Pollutants on Human Health

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Environmental pollutants have profound and often irreversible effects on human physiology. Understanding the direct correlation between specific toxic agents and their corresponding diseases is a frequent testing point in the UGC NET examination.

Heavy Metal Toxicity and Syndromes

Heavy metals bioaccumulate in the human body, meaning they are absorbed faster than they are excreted, leading to severe neurological and physiological damage.

Major Pollutants and Associated Diseases
Pollutant Primary Source Health Impact / Disease
Mercury (Hg) Industrial wastewater, coal combustion. Minamata Disease: A severe neurological syndrome causing ataxia, numbness, and paralysis. (Historically linked to contaminated fish in Minamata Bay, Japan).
Cadmium (Cd) Battery manufacturing, electroplating. Itai-Itai Disease: Severe softening of the bones and kidney failure. (Historically linked to river pollution in Japan).
Lead (Pb) Paints, leaded gasoline (historically), e-waste. Neurological damage (especially in children), lowered IQ, anemia, and kidney damage.
Arsenic (As) Groundwater contamination (major issue in West Bengal & Bangladesh). Blackfoot Disease: Skin lesions, peripheral vascular disease leading to gangrene, and cancer.

Airborne Pollutants and Respiratory Diseases

Occupational hazards and urban smog expose humans to dangerous particulate matter and gases.

  • Carbon Monoxide (CO): Binds to hemoglobin with an affinity 200 times greater than oxygen, causing asphyxiation (often from incomplete combustion of fossil fuels).
  • Silica Dust: Inhalation of crystalline silica dust (common in mining and stone cutting) leads to Silicosis, an incurable lung disease.
  • Asbestos: Used in construction and insulation; inhalation of fibers causes Asbestosis and Mesothelioma (a type of lung cancer).
  • Particulate Matter (PM 2.5 & PM 10): Microscopic particles that penetrate deep into the lungs and cardiovascular system, exacerbating asthma and causing heart attacks.

💡 Examiner's Note

Direct match-the-following questions are very common here. Memorize the exact pairs: Mercury = Minamata, Cadmium = Itai-Itai, Arsenic = Blackfoot.

Academic References

  • Gadgil, M. (2011). Report of the Western Ghats Ecology Expert Panel. Ministry of Environment and Forests, Government of India.