The new air quality monitoring station at Chandni Chowk, which measures the concentration of Particulate Matter (PM) 1, has thrown up worrying results. According to the data collected by the Ministry of Earth Science’s System of Air Quality and Weather Forecasting and Research (SAFAR) between September 11 and October 16, the concentration of the particle, which is under 1 micron in size, touched 54.32 micrograms per cubic metre on October 16. This was the highest this season so far. There are no national or international acceptable standards for PM1 concentration in the air, unlike those for PM2.5 and PM10. But studies across the world have indicated a link between the pollutant and cardio-vascular disease.
Currently, PM1 is considered part of PM 2.5 pollutant, but after building adequate infrastructure to measure the concentration of bigger particles, the Centre and the state have started to build equipment to measure smaller particles as well. Delhi has close to 40 air quality monitoring stations, all of which measure the concentration of PM 2.5 and PM 10 along with that of gases like ozone, nitrogen dioxide and carbon monoxide. The SAFAR station at Chandni Chowk is the only one measuring PM1. According to Gufran Beig, SAFAR’s programme director, trends show that PM 1 is a significant part of the PM 2.5 that is being measured at most other stations.
“In some cases, PM1 is almost 60 micrograms per cubic metre. This is worrying because the acceptable limit for PM2.5, which is a bigger particle and relatively less dangerous, is 60 micrograms per cubic metre. While there aren’t any acceptable limits for PM1 yet, we know that this concentration should be much lower,” he said.