The average air quality index (AQI) in Delhi was reported to be inching close to ‘severe plus’ levels as it touched 494 on Monday (November 18) at 6 pm, according to the Central Pollution Control Board (CPCB) data. The data also showed that the hourly average PM2.5 and PM10 levels had been on a sharp increase since Sunday noon. The average PM2.5 level was 354 micrograms per cubic metre — more than 20 times the standard prescribed by the World Health Organization (WHO). The PM10 levels were also above the threshold by around 12 times the WHO standards. In response, the Stage IV of the Graded Response Action Plan (GRAP) kicked in on Monday. GRAP is a set of emergency measures that are implemented to prevent further deterioration of air quality once it reaches a certain threshold in the Delhi-NCR region. Under GRAP IV, entry of truck traffic into Delhi is stopped, light commercial vehicles (LCVs) registered outside Delhi, other than EVs/CNG/BS- VI diesel, are not permitted to enter Delhi, construction and demolition activities are banned, etc. Although such measures might bring down peak pollution levels, their impact will be limited. To significantly improve air quality in New Delhi, a host of preventive steps need to be taken in the national capital as well as the adjoining areas, according to a 2016 report, ‘Comprehensive Study on Air Pollution and Green House Gases (GHGs) in Delhi’, by Indian Institute of Technology Kanpur. A successful execution of these measures is expected to bring down PM 2.5 levels to 72 μg/m3 and PM 10 levels to 120 μg Here is a look at the 10 steps listed in the report that need to be implemented to control the air pollution in the region. What measures are needed to improve Delhi’s air quality?