Environmental Pollution
Unit 3. Covers Pollutants, sources and sinks; Air pollution; Air quality standards and monitoring; Vehicular and industrial emissions; Water pollution; Lakes and eutrophication; Soil pollution.
About this unit
This unit explains what pollutants are, where they come from and where they end up, and how they harm health and ecosystems. It covers air pollution (atmosphere layers, smog, acid rain, ozone), air quality standards and monitoring, vehicle and industrial emissions, water pollution and its indicators, lakes and eutrophication, and soil pollution and simple soil tests. Indian laws and agencies (CPCB, SPCBs) appear throughout.
How to prepare
Memorise: the four atmosphere layers in order; primary vs secondary pollutants; the two kinds of smog; NAAQS limits for PM10 and PM2.5; AQI categories; BS-VI and the CNG story; meanings of pH, DO, BOD and COD. Practise one BOD calculation and one soil water-holding calculation. Link eutrophication to BOD and DO: they are one connected story.
Topics in this chapter
Pollutants, sources and sinks
Basic concepts, health and ecosystem impacts, and Indian pollution laws.
5 questionsAir pollution
Structure of the atmosphere, primary and secondary pollutants, acid rain, smog and tropospheric ozone.
5 questionsAir quality standards and monitoring
NAAQS, AQI, sampling methods, NAMP and the role of pollution control boards.
5 questionsVehicular and industrial emissions
Emission standards and the CNG programme.
5 questionsWater pollution
Sources of pollution and water-quality indicators such as pH, BOD, COD and dissolved oxygen.
5 questionsLakes and eutrophication
Lake stratification and eutrophication.
5 questionsSoil pollution
Sources, soil properties and simple soil tests.
5 questions