Air and Water Pollution: Burden and Strategies for Control

Introduction

• Environmental pollution impacts health across various organ systems.
• Links with other health issues: diarrheal diseases, respiratory diseases, cancers, neurological disorders, cardiovascular disease.

Nature, Causes, and Burden of Pollution

• Global burden from environmental pollution: 23-30% of diseases.
• Types of diseases: infectious, respiratory, vector-borne.
• Outdoor air pollution: 0.6-1.4% of disease burden in developing regions.
• Lead in air, water, and soil contributes ~0.9%.

Air Pollution

Types of Air Pollutants

• Suspended Particulate Matter (PM):
  • PM10 and PM2.5 (more hazardous, reach alveoli).
  • Sources: diesel exhaust, coal fly ash, wood smoke, mineral dusts.
• Gaseous Pollutants:
  • Sulfur compounds (SO2, sulfur trioxide), carbon monoxide.
  • Nitrogen compounds (NO, NO2, ammonia).
  • Organic compounds (hydrocarbons, volatile organic compounds).
  • Ozone formation from nitrogen oxides and hydrocarbons.

Sources of Outdoor Air Pollution

• Combustion of petroleum products and coal.
• Motor vehicles: PM, nitrogen oxides, carbon monoxide, lead.
• Industrial processes: cement factories, metal smelters.
• Catastrophic emissions: Bhopal disaster, Chernobyl.

Exposure to Air Pollutants

• Health effects depend on exposure levels (indoor and outdoor).
• Vulnerable groups: children, elderly.
• Workplace exposure in industries like coal mining and cement production.

Health Impacts

• Increased respiratory and cardiovascular morbidity and mortality.
• Long-term studies: PM2.5 linked to cardiovascular mortality and lung cancer.
• Urban air pollution contributes to 5% of lung cancer, 2% of cardiovascular/respiratory deaths.

Water Pollution

Chemical Pollution Sources

• Surface water: direct drinking source contamination.
• Groundwater: arsenic, fluoride from soil.
• Coastal areas: mercury contamination (Minamata disease).

Sources of Chemical Water Pollution

• Point-source: Industrial discharges.
• Nonpoint-source: Runoff from agriculture, stormwater.
  • Contaminants: fertilizers, pesticides, heavy metals.

Health Effects

• No global burden estimate, but local impacts can be severe (e.g., arsenic in Bangladesh).
• Chronic exposure: liver toxicity, kidney damage.
• Endocrine disruptors: reproductive, developmental issues.

Interventions

Reducing Air Pollution

• Technical solutions: lead-free gasoline, catalytic converters.
• Policies: congestion fees, reducing unnecessary driving.
• Power plants: filtering and scrubbing methods.

Reducing Water Pollution

• Minimize chemical use in industries and agriculture.
• Cleaner production processes.
• Treat hazardous waste, recycle chemical containers.

Economic Analysis

• Cost-benefit analyses show interventions can be economically beneficial.
• Examples include air pollution control in Tokyo and Mexico City.
• Water pollution interventions: significant returns on investments.

Research and Development

• Need for research on long-term health effects and economic analysis.
• Study specific vulnerabilities in developing countries.
• Assess interventions for climate change-related health risks.

Conclusion

• Pollution control is critical for disease control.
• Partnerships between sectors needed for effective interventions.
• Early consideration of alternative transportation methods in urban planning is crucial.