India, Oct. 14 -- Farm fires, a major reason for pollution in northwestern India and the Delhi-National Capital Region (NCR), have been declining year-on-year. But multiple studies have suggested a trend of farmers setting their fields ablaze after 3pm to evade satellite captures, prompting the government to call for intensified ground-level monitoring.

Air quality in Delhi and NCR starts worsening from mid-September, with stubble burning as a precursor to winter pollution. Smog chokes the Capital every winter. Subsequent fireworks during the festive season, especially around Diwali, worsen the situation despite curbs, which are violated every year. PM2.5 is the dominant pollutant affecting the air quality. Secondary particulates formed ...