Post-Diwali pollution in Delhi likely to be lower than last 3 years

New Delhi: The post-Diwali pollution levels in Delhi are likely to be the lowest as compared to the past three years as favourable wind speed would possibly negate the impact of firecracker emissions and stubble burning, according to a government air quality monitor.

Although Delhi’s air quality was predicted to touch the “severe” mark in the early hours of yesterday, the peak level of PM2.5 is likely to be the lowest in the past three years, the System of Air Quality and Weather Forecasting and Research (SAFAR) said in a special report on Diwali.

Favourable speed of surface winds will greatly help in dispersion of pollutants, it said.

PM2.5 is particulate matter equal to or less than 2.5 microns in diametre. These tiny particles can enter deep into the lungs and even the bloodstream.

Last year, the overall air quality index post-Diwali was recorded in the “severe plus emergency” category at 642. In 2017, the AQI was recorded at 367, while it was 425 in 2016.

An AQI between 0-50 is considered

“good”, 51-100 “satisfactory”, 101-200 “moderate”, 201-300 “poor”, 301-400 “very poor”, and 401-500 “severe”. Above 500 is “severe-plus emergency” category.

A “severe plus emergency” AQI essentially means that even healthy people may suffer from respiratory illnesses on prolonged exposure. This air will seriously affect those with ailments, according to a SAFAR advisory.

The SAFAR said the farm fire count in Haryana and Punjab had more than doubled over the past two days, surging from 1200 to 2700, and the share of stubble burning in Delhi’s pollution was likely to increase significantly from yesterday.

On Sunday, the share of smoke from farm fires in Delhi’s PM2.5 concentration was expected to be 19 per cent. The SAFAR said the favourable speed of high boundary-layer winds (20 kmph) on Sunday night and yesterday morning would counter the expected high impact of firecracker and biomass emissions.