NEW DELHI: Even though Delhi experienced a deadly smog episode spanning more than a week in November, a recent report by the Central Pollution Control Board indicated that the overall air quality might have improved in 2017 compared to 2016. In a note, “significant achievement 2017”, CPCB scientists listed steps that the pollution watchdog took last year and displayed monthwise air-quality data, indicating that while the number of “satisfactory” and “moderate” days increased in 2017, “very poor” and “severe” days came down.The note also claimed that there was no high-level coordination in 2016, but, in 2017, there was a review of the situation by the PMO, secretary (Union environment ministry) and the chief secretary. To back this, CPCB noted that the number of continuous or real-time monitoring stations were increased from 18 to 38 in Delhi; another four were installed in Haryana, three in Uttar Pradesh and two in Rajasthan. It stated that there was now a 24X7 unified control room, which dealt with public grievances, forecast, remote-sensing data access, real-time data access and calculating a particulate matter-based AQI.CPCB claimed that a 42-point action plan, which was developed in 2015 under the then environment minister, Prakash Javadekar, was implemented in 2017. At a review meeting in 2016, it was found that hardly any of the 42 points were implemented in 2016. Among other steps, CPCB listed formation of 40 air-quality monitoring teams, notification of construction and demolition waste norms, and a decision to leapfrog to BS-VI-compliant fuel in 2018 in the capital.“Delhi is significantly impacted by meteorological factors. There is also intrusion of pollutants from the nearby areas.The improvement we are seeing basically backs the fact that if we can control ground-level emissions, we will see some difference in air quality. In 2017, the onset of winter was late, but we still managed to see some improvement. Increasingly, the clear seasonal variations seen earlier are shifting and this also impacts air quality,” Dipankar Saha, head of CPCB’s air quality lab, said, adding that “multiple agencies had taken action to control air pollution in 2017 under the graded response action system”.For the first time since May 2015 (when AQI mapping started), Delhi recorded two “good” air-quality days in 2017. Also, “very poor” days reduced from 97 in 2016 to 76 in 2017 and “severe” days came down from 26 to eight. “This basically shows that the duration, frequency and intensity of smog episodes will reduce if action is taken to control emissions. GRAP came into force last October, but some action was taken since January 2017 like the Badarpur power plant was shut for the entire winter and an environment compensation charge was imposed on trucks. Now, GRAP has ensured consistent action,” Anumita Roychowdhury, executive director, Centre for Science and Environment, said.Last week, a top CPCB scientist had said that the agency might consider using advanced LiDAR (Light Detection and Ranging) devices to vertically monitor the air quality of NCR.This year is likely to be even more eventful for those tracking how the capital fights air pollution because the oil ministry has promised to roll out BS-VI in Delhi in 2018.“The moment you improve fuel quality, the emission control systems in the existing fleet will perform better, wear and tear will be less and PM emissions will be lower. But the maximum benefit will be felt when the automobile technology is advanced to support BS-VI fuel. SC has directed the environment ministry to notify the comprehensive action plan, which means long-term solutions will also be taken,” added Roychowdhury.