Post-Diwali air pollution in Delhi 'severe', better than last 2 yrs

NEW DELHI: Air pollution in the Capital soared to alarming levels till late Friday night, reaching as much as five times over the safe limit because of the bursting of firecrackers despite a Supreme Court ban on their sale in the NCR, says a survey.However, it was the cleanest Diwali of Delhi in the last three years.

Conducted by air quality mobile app Blueair Friend App, the survey said the Air Quality Index (AQI) was 553 in Anand Vihar area which was five times higher than the safe limit of 51-100.

AQI level from 0-50 is considered good, 51-100 is satisfactory, 101-200 is moderate, 201-300 is poor, 301-400 is very poor, 401 and above is severe.

The survey is the outcome of the real-time air quality data monitored on Blueair Friend App on Thursday evening.

In Paschim Vihar the AQI level was 365 while in RK Puram it was 286, the survey said, adding that in Faridabad and Dwarka area it jumped to 406 and 254 respectively.

The pollution indicator of state-run System of Air Quality Forecasting and Research (SAFAR) turned a deep shade of brown, indicating 'severe' air quality in the city, which may affect healthy people and seriously impact those with existing respiratory or cardiovascular diseases. The 24-hour rolling average of PM2.5 and PM10, ultrafine particulates which are up to 30 times tinier than the width of a human hair, were 424 and 571 micrograms per cubic metre (ug/m3) respectively, multiple times higher than the safe limits of 60 and 100.

The US embassy's pollution monitor recorded 'hazardous' air quality with the index scoring an alarming 878, which the mission considers "beyond its air quality index" (AQI), which ends at 500.

But unlike the last year, the run-up to Diwali festivities was much cleaner this time.

Even the Diwali evening was relatively quiet and promising, suggesting that the ban on the sale of firecrackers in the Delhi-NCR region imposed by the apex court has worked.

This was captured by the Central Pollution Control Board (CPCB) which had Delhi's AQI (air quality index) at 319, which is considered 'very poor', for October 20. However, since the figure was released at 5 pm, it could not quite record what followed thereafter.

As the clock ticked, frenzied celebrations picked up and noisy and relentless bursting of firecrackers continued till the wee hours, sending pollution graph off the charts.

The online indicators of pollution monitoring stations in the city glowed red, indicating a 'very poor' air quality as the volume of ultrafine particulates PM2.5 and PM10, which enter the respiratory system and manage to reach the bloodstream, sharply rose from around 7 pm on Thursday.

The line graphs of the pollution data of the Delhi Pollution Control Committee (DPCC) stations were disturbing.

In station after station, the volume of PM2.5 and PM10 built up rapidly around 7 pm and peaked post-midnight, soaring up to 10 times above the safe 24-hour limits.

For example, the RK Puram monitoring station recorded PM2.5 and PM10 at 878 and 1,179 micrograms per cubic metre at around 11 pm. The monitors stopped working after midnight, suggesting that the pollutants had shot through the roof. While it is difficult to quantify the immediate effect of the ban on firecrackers, residents across the national capital felt the beginning was promising with neighbourhoods reporting much lesser noise and smoke till about 6 pm, compared to the previous years.

But as the festivities picked up, the decibel levels kept rising.

The situation was similar, if not worse, in the neighbouring regions of Delhi such as Gurugram, Noida and Ghaziabad, where crackers were burst, as usual, raising question marks on the efficacy of the administration in enforcing the apex court's ban.

However, if one goes by SAFAR's forecast, post-Diwali air will not be as poor as last year, which was the worse in at least three decades. It said a host of favourable meteorological conditions were helping prevent smoke-filled air from the agricultural belt of Haryana and Punjab from entering the national capital.

Had that not been the case, Delhi's air, already saturated with pollutants, would have turned deadlier.

The Supreme Court-appointed Environment Pollution Prevention and Control Authority (EPCA), which is empowered to enforce the Graded Response Action Plan (GRAP) to combat air pollution in Delhi-NCR, kicked off a series of preventive measures on October 17.

Measures under the GRAP's 'very poor' and 'severe' categories, which include a ban on diesel generator sets, have come into effect and will remain in force until March 15.