SAFAR warns against deteriorating air quality in Delhi ahead of Diwali

Delhi's air quality is expected to deteriorate to 'severe plus emergency' category after Diwali, according to a government-run agency.

Air quality will be "bad" on November 8 even if "partial toxic crackers" are burned compared to last year, the Centre-run System of Air Quality Forecasting and Research (SAFAR) said.

The PM10 (particles in the air with a diameter of fewer than 10 micrometres) is expected to reach 575 and PM2.5 (particles in the air with a diameter of fewer than 2.5 micrometres) is expected to reach 378 a day after Diwali, recording the worst air quality of the year, it said.

"Most striking factor is that share of PM2.5 (relatively more harmful than coarser particles) in PM10 has already increased by 10-20 per cent due to fire emissions which further increased due to crackers as compared to normal days," an official said.

"The share of PM2.5 is 60-70 per cent. Combination of several rapidly changing weather parameters play role in controlling the air pollution at this time and dynamics changes even if one parameter behaves erratically," he said.

The SAFAR said Delhi's air quality is expected to deteriorate to 'severe plus emergency' category after Diwali and the air quality "will be bad on November 8 even if partial toxic crackers are burned compared to last year".

"Even if 50 per cent of a total load of toxic firecrackers as compared to Diwali-2017 is added, the prevailing weather conditions will aggravate the high smoke level and make air quality to persist in severe range for at least two days on November 8 and November 9," SAFAR said in a report.

This scenario is likely to hold the locally generated crackers emissions within the NCT, slowing down the dispersion, resulting in increasing levels of PM2.5 and PM10 pollution, it said.

The Supreme Court has permitted the sale and manufacture of low emission "green" firecrackers countrywide and fixed a two-hour time period from 8 pm to 10 pm for bursting them on Diwali and other festivals.