NEW DELHI: The city’s overall air quality continued to remain ‘very poor’ on Friday, but no drastic decline is likely in the next three days as strong winds are expected to blow in the region, the government’s air quality monitoring and forecasting service SAFAR said.
After a brief respite, brought about by rain and increase in wind speed, the national capital’s air quality plunged to the ‘very poor’ category on Thursday because of high humidity and light rain.
“Isolated drizzle, cloudy weather and calm winds prevented boundary layer growth and led to the accumulation of local emissions (on Thursday),” SAFAR said. The city experienced “slight secondary particulate formation in the early hours (on Friday) but (it) could not multiply much”, it said.
Secondary particles are products of complicated atmospheric reactions between primary particles, such as particulate matter, sulphur dioxide and nitrogen dioxide directly emitted by stubble burning and vehicles, in the presence of other factors such as sunlight and moisture. Examples of secondary particles include sulphates, nitrates, ozone and organic aerosols.
(With PTI inputs)