Air quality in Delhi and surrounding regions continued to be in the red zone, with several monitoring stations reporting particulate matter levels higher than 500 micrograms per cubic metre.
The bad air was classified as 'severe' by forecast agency, SAFAR, which attributed it to secondary particulate formation due to a drizzle over Delhi.
Such rain is particularly detrimental to air quality as it makes particulate matter 'stickier' and harder to be flushed out by wind.
However, the agencies said an increase in windspeed and a clearing of the air by Sunday is likely. “...An increase in local Delhi wind speed is forecast for the next three days which may increase ventilation and improve air quality marginally,” SAFAR’s Friday report said.
Stubble burning, a major contributor to this month's spike in pollution, may cease to be a key cause in the coming days as the winds that bear pollutants are likely to shift away from Delhi.
The contribution of stubble burning had come down to 5%, according to SAFAR, from a high of 25% on November 12.
The Supreme Court on Friday expressed concern that a reduction in stubble burning hadn't reduced pollution in Delhi.
The Centre said it was examining the feasibility of putting up 'smog towers' to reduce pollution in Delhi. These are likely to be huge towers that suck in the surrounding air, pass it through a system of filters and eject clean air. Union environment secretary C.K. Mishra had said earlier this week that miniature versions of smog towers—called WAYU filters — that were being tested since last year hadn't worked.
