Transport, farm fires keep air 'very poor', Pg3.

Key Highlights:

• Delhi's air quality remained in the 'very poor' category on Friday with an AQI of 322, increasing from 311 the previous day.
• Stubble burning contributed 8.68% to Delhi's PM2.5 levels on Friday, projected to rise to 30.91% on Saturday.
• The transport sector was the main contributor to PM2.5 levels in Delhi on Friday at 17.21%.
• A total of 565 farm fires were recorded on Friday, with Madhya Pradesh leading at 237 fires.

Detailed Insights:

• The Decision Support System (DSS) forecasts a sharp increase in the contribution of stubble burning to Delhi's PM2.5 levels.
• Delhi was recorded as the most polluted city in the country on Friday, followed by Ghaziabad with an AQI of 314.
• Between September 15 and November 7, a total of 7,454 burning events were recorded in Delhi and surrounding states, with almost half in Punjab.
• Farm fire numbers are at a six-year low in Punjab and Haryana this year, while Uttar Pradesh has reported increased fire activity.
• Northwesterly winds from the Himalayan region have lowered temperatures in Delhi, with the minimum temperature recorded at 12.7°C.
• Strong winds, with speeds up to 17 kmph, helped mitigate some of the impact of cooler temperatures on air pollution in Delhi.

Key Concepts Involved:

• AQI (Air Quality Index): A measure of air quality based on concentrations of pollutants.
• PM2.5: Fine particulate matter with a diameter of 2.5 micrometers or less, a major air pollutant.
• Stubble Burning: The practice of setting fire to crop residue after harvest, contributing to air pollution.