Air in Delhi turns 'poor' after four months, high ozone levels recorded, Pg3.

Key Highlights:

• Delhi's air quality turned 'poor' for the first time in over four months on Tuesday, with the 24-hour average Air Quality Index (AQI) at 211 at 4 pm.
• The Central Pollution Control Board identified ground-level ozone and Particulate Matter (PM) 10 as the main pollutants over the last three days.
• Stage 1 of the Graded Response Action Plan (GRAP) has been activated by the Commission for Air Quality Management (CAQM) to combat the rising pollution levels.
• Between September 15 and October 14, a total of 552 farm fires were recorded in Punjab, Haryana, UP, Madhya Pradesh and Rajasthan, with UP recording the highest at 225.

Detailed Insights:

• The increase in ground-level ozone, formed by the reaction of NOx and VOCs from vehicular pollution, power plants, and industries, poses health risks, including aggravated lung diseases and asthma.
• PM 10 levels have risen due to road dust, exacerbated by dry conditions and reduced wind speed, as reported by the Delhi Pollution Control Committee and the India Meteorological Department (IMD).
• Delayed rice harvesting in Punjab and Haryana, caused by late rain and flooding, may postpone the peak of farm fires until November, potentially leading to better air quality during Diwali in Delhi.
• Burning rice stubble, which is high in silica and unsuitable for cattle feed, is a common practice among farmers to clear fields after machine harvesting, contributing significantly to air pollution.

Key Concepts Involved:

• Air Quality Index (AQI): A measure of air quality based on concentrations of various pollutants.
• Particulate Matter (PM): Microscopic solid or liquid matter suspended in the air.
• Graded Response Action Plan (GRAP): A set of measures to be implemented based on air quality levels.