Air/water pollution and Indian laws

Pollution basics

Pollution is the introduction of matter or energy at levels harmful to organisms, materials or ecosystems. Primary air pollutants are emitted directly, such as SO2, CO and particulate matter. Secondary pollutants form in the atmosphere; ground-level ozone is a harmful photochemical oxidant, unlike protective stratospheric ozone. PM2.5 can penetrate deep into lungs. Temperature inversion can trap pollutants near the surface.

Water pollution

Sewage, industrial effluents, agricultural runoff, plastics, pathogens and oil degrade water. Biochemical oxygen demand (BOD) is the oxygen consumed by microorganisms while decomposing biodegradable organic matter; high BOD normally indicates organic pollution. Chemical oxygen demand is a broader chemical oxidation measure. Eutrophication occurs when excess nitrogen and phosphorus stimulate algal growth; decomposition then depletes dissolved oxygen. Bioaccumulation is build-up within one organism, while biomagnification increases concentration across trophic levels. Acid rain is chiefly associated with SO2 and NOx, not nutrient enrichment.

Indian laws

The Water (Prevention and Control of Pollution) Act, 1974 created the Central and State Pollution Control Boards and regulates water pollution. The Air Act, 1981 provides a framework for preventing and controlling air pollution. The Environment (Protection) Act, 1986, enacted after the Bhopal disaster, is an umbrella law empowering the Union government to set standards and regulate hazardous substances and activities. The National Green Tribunal Act, 2010 created a specialised forum and applies sustainable development, precautionary and polluter-pays principles. The Commission for Air Quality Management Act, 2021 provides coordinated air management for NCR and adjoining areas.

Rules under the umbrella law cover solid, plastic, biomedical, hazardous, e-waste and construction waste. CPCB and State Boards monitor and enforce; environmental impact assessment is a regulatory process, not a standalone pollution law.

Prelims focus

Remember the sequence Water 1974, Air 1981 and Environment 1986. The Bhopal gas was methyl isocyanate, but the Act is not named after that chemical. Separate BOD, COD, eutrophication and biomagnification. UPSC often tests year-law pairs, secondary pollutants, and the difference between a board, a tribunal and an executive rule.

Prelims revision checklist

Identify the definition first, then connect it to the relevant institution, date, process and example. Do not treat a scientific mechanism as a policy instrument, an international label as automatic domestic legal status, or a rank as ownership. Watch absolute words such as “always” and “only”; they are rarely correct unless part of a formal definition. In current-affairs questions, apply the stable principle and verify changing figures or variants from an official source.

Analogy

Air/water pollution and Indian laws — Analogy

Think of an aquarium: a little waste can be processed, but too much consumes oxygen. Pollution laws are the tank’s limits, filters and enforcement.