Delhi’s air pollution levels this year much better than that of 2016

The air quality was “severe” for eight days in 2017 as against 26 the previous year, according to data from the Central Pollution Control Board (CPCB).

Despite the toxic haze that engulfed Delhi for more than a week in November, the national capital breathed comparatively cleaner air this year than it did in 2016.

Experts said that the credit for this upswing goes largely to favourable weather conditions, and suggested that some tough anti-pollution measures introduced in 2017 may have worked. (AP File Photo)

The air quality was “severe” for eight days in 2017 as against 26 the previous year, according to data from the Central Pollution Control Board (CPCB). Besides the three-time drop in “severe” days, the air quality was “very poor” for 76 days as against 97 in 2016 and “poor” for 114 days as compared to 122 the previous year.

“In 2016, Delhi didn’t witness a single day when air quality was ‘good’. In 2017, the city got at least two days of ‘good’ air, which means pollution levels were bare minimum,” said D Saha, head of the CPCB’s air quality laboratory.

Hindustan Times air quality monitor

An air quality index (AQI) of 0-50 is considered good, 51-100 satisfactory, 101-200 moderate, 201-300 poor, 301-400 very poor and 401-500 severe. There was no comparative data available for the whole of 2015 as the national AQI came into effect in May that year.

Experts said that the credit for this upswing goes largely to favourable weather conditions, and suggested that some tough anti-pollution measures introduced in 2017 may have worked.

Stringent measures under the Supreme Court-mandated graded response action plan (GRAP) to control pollution were enforced for the first time since October 17. They will run till March 15 next year.

A range of additional steps such as mechanised sweeping of roads and a crackdown on the burning of garbage were carried out through the year to reduce street dust and smoke that leads to smog.

“The duration and frequency of smog episodes have come down to some extent. But pollution levels are still very high. More sustained and aggressive action is needed to bend the pollution graph,” said Anumita Roychoudhury, executive director (research and advocacy) at the Centre for Science and Environment.

The Supreme Court’s ban on firecrackers during Diwali also had an impact. A report by SAFAR, an agency under the ministry of earth sciences, had stated that the level of emission from fireworks fell around 40% during the festival this year, compared to 2016.

But some experts pointed out that it would be too early to conclude that the steps were showing results.

“We can only say air quality has improved when we monitor pollution data over a period of at least five to 10 years. Secondly, a simple AQI data doesn’t give a fair idea of the level of pollutants. We need to monitor each pollutant over a period before coming to a conclusion,” said SN Tripathi, coordinator at the Centre for Environmental Science & Engineering in IIT Kanpur.

Tripathi also warned that the authorities should not be complacent just because there were some signs of improvement.