According to Central Pollution Control Board, the particulate size which is responsible for causing greatest harm to human health is
Answer & explanation
Correct answer: option 2
The correct answer is Option (2) → PM 2.5
Option (2) PM 2.5 — Correct. The Central Pollution Control Board says that particles 2.5 micrometres or less in diameter (PM 2.5) do the greatest harm to health. They can be breathed deep into the lungs and cause breathing problems, irritation and lung damage.
Note 1: A similar question was also asked in CUET (UG) 2023 on 30-05-2023 (Slot 1).
Note 2: This question is from Chapter 16, Environmental Issues, of the pre-rationalised NCERT book. This chapter is not in the present NCERT book (2026-27). The extract below is from the pre-rationalised edition.
NCERT Extract (Pre-rationalised edition, Chapter 16, Environmental Issues):
Air Pollution and Its Control – “… Recently we have realised the dangers of particulate matter that are very very small and are not removed by these precipitators. According to Central Pollution Control Board (CPCB), particulate size 2.5 micrometers or less in diameter (PM 2.5) are responsible for causing the greatest harm to human health.”