Lockdown cuts PM2.5, PM10 levels by half in Delhi: CPCB

NEW DELHI: With very few vehicles on roads, only essential commercial units functioning due to the coronavirus-forced lockdown and a weather favourable for dispersion of pollutants, the Central Pollution Control Board (CPCB) has reported 46 per cent reduction in PM2.5 levels and 50 per cent depletion in PM10 concentrations in the national capital.

The apex pollution control body has analysed data from continuous ambient air quality monitoring network of 38 stations in Delhi between March 16 and April 15. Air quality trends have been studied in two phases -- pre-lockdown phase of March 16 to 21 and the lockdown phase from March 25 to April 15.

In its report, the CPCB said, "Significant reduction in PM2.5, PM10 and NO2 levels observed. Overall, 46 per cent reduction in PM2.5 and 50 per cent reduction in PM10 concentration observed during the lockdown period."


PM2.5 refers to particulate matter having diameter less than 2.5 micrometers which can enter the lungs and even the bloodstream.

The CPCB said reduction in PM10 and PM2.5 levels primarily indicate depletion in combustion and industrial sources of pollution which are common to both fractions of particulate matter.

Since 81 per cent of Delhi's nitrogen oxide comes from the transport sector, according to TERI Emission Inventory, 2018, restrictions on vehicular activity led to 56 per cent reduction in NO2 levels and over 37 per cent cut in carbon monoxide (CO) concentration during the lockdown period, compared to the pre-lockdown period, it said.

Due to restrictions on the transport sector and industrial operations, the two major sources of benzene emissions, a 47 per cent reduction in benzene level has been observed, the CPCB report stated.