CORE Key Points at a Glance

  1. 1

    Pollution questions usually combine source, pollutant, indicator, law and control measure.

  2. 2

    CPCB AQI 101-200 is Moderate; this is a high-frequency measurement anchor.

  3. 3

    Water Act 1974, Air Act 1981 and Environment Protection Act 1986 form the statutory ladder.

  4. 4

    Stockholm, Minamata, Basel, Montreal and MARPOL map to different pollutant families.

  5. 5

    Sulphur dioxide and nitrogen oxides are the classic acid-rain precursor pair.

  6. 6

    Solid Waste Management Rules, 2026 mandate four-stream source segregation and strengthen municipal and bulk-generator duties.

  7. 7

    BS-VI from 1 April 2020 tightened vehicle-emission governance.

  8. 8

    Jaipur, Bhiwadi and Sambhar provide Rajasthan hooks for city air, industry and inland water.

CORE Pollution as a measurable environmental pressure

Pollution means an undesirable change in air, water, soil, noise or radiation conditions that harms health, ecosystems or materials. A pollutant can be primary, such as sulphur dioxide from fuel combustion, or secondary, such as ground-level ozone formed through sunlight-driven reactions. Particulate matter is tracked as PM10 and PM2.5, while water clarity can be expressed through turbidity in nephelometric turbidity units. The Central Pollution Control Board air-quality scale places the AQI range 101-200 in the Moderate category, a recurring measurement anchor for Indian city questions. Rajasthan makes the idea concrete: Jaipur under NCAP is monitored through a clean-air action frame, while Bhiwadi industrial air pollution issue shows how industrial fuel, dust and transport sources can combine in an NCR-linked cluster.

PREDICTED Predicted RAS Questions

Based on PYQ trends and 2026 syllabus analysis

1 MCQ According to the Indian air-quality category scale, the range 101-200 belongs to which category?
  1. A Good
  2. B Moderate Correct answer
  3. C Very Poor
  4. D Severe

Explanation

Moderate is correct because CPCB's AQI category table places 101-200 in that band. Good is 0-50, Very Poor is 301-400, and Severe is above 400.