Delhi's air quality improving, shows data

NEW DELHI: It may seem too good to be true, but 2017 has so far seen reasonably better air quality than 2016. The Central Pollution Control Board shared its air quality index data with TOI, which show the average AQI this January was 304 against 369 in the same period last year. Still, the air quality was in the "very poor" category in both cases.

AQI for February so far is 265 — in "poor" category against 337 in the "very poor" category last year.

The Centre for Science and Environment's analysis of PM2.5 (fine, respirable pollution particles) concentrations from six stations in Delhi also shows a considerable decline from 284 micrograms per cubic metres in January 2016 to 181 this year, and 158 micrograms per cubic metres in 2016 February compared to 146 this year. While data collated by CSE show that even November and December 2016 levels were lower than that of 2015, but the difference was not as perceptible as in January this year.


"After the Diwali smog, we saw a very high peak in November this year, possibly the highest for the season. That led to agencies taking action, including closing of the Badarpur power plant and implementation of SC's order of imposing environment compensation charge for trucks. There was also better enforcement of other actions, so we cannot discount the impact of action against pollution sources. We may have started bending the air pollution curve, but levels are still very poor. The important thing is to maintain the momentum to sustain these gains," said Anumita Roy Chowdhury, head of CSE's clean air campaign.

Dipankar Saha, head of CPCB's air lab, had similar observations. "Severe days have reduced or are not there in 2017. Peaks are comparatively lower. There are two reasons — meteorological conditions are not as hostile as in November. Somehow, levels haven't shot up. The other factor is that people may be more aware. Agencies may be also working to control various local sources."

But monthly average PM2.5 concentration for January 2017 continues to be at least three times the national 24-hour standard and more than seven times the WHO 24-hour guideline.