Environmental Pollution

Environmental pollution for UPSC: air, water, soil, noise and plastic pollution — pollutants, standards, AQI, BOD and COD, biomagnification, waste rules and control programmes.

SyllabusGS III · Conservation, environmental pollution and degradation (GS III); general issues on environmental ecology (Prelims)

Pollution is the most “lived” part of the Environment syllabus — winter smog in north India, foaming rivers, landfill fires and plastic in drains all trace back to the concepts in this chapter. UPSC asks the science behind them and the standards and laws that govern them.

What UPSC asks

Prelims: pollutants in the National Air Quality Index and the National Ambient Air Quality Standards; types of smog; BOD, COD and dissolved oxygen; eutrophication; biomagnification; diseases linked to specific pollutants; noise limits; plastic and waste-management rules.
Mains GS III: causes of urban air pollution and why programmes have under-delivered, river pollution and sewage treatment, solid-waste and plastic management, and the health and economic costs of pollution.

Key sub-topics

Sub-topic	What to master
Air pollution	Primary and secondary pollutants, PM2.5 and PM10, smog types, acid rain, standards, AQI, NCAP, CAQM
Water pollution	Point and non-point sources, BOD/COD/DO, eutrophication, heavy metals and diseases
Soil and solid waste	Pesticides, heavy metals, e-waste, plastic, waste-management rules
Noise	Noise Pollution (Regulation and Control) Rules, 2000
Bioaccumulation	Biomagnification of DDT and mercury

The laws and bodies that regulate pollution — the Air and Water Acts, the CPCB and SPCBs, the NGT — are in Environmental Laws and Institutions.