Impact Of Lockdown (25th March To 15th April) On Air Quality

The nationwide Lockdown, in effect since the midnight of 24 March in view of COVID-19 pandemic, has resulted in significant improvement in air quality in the country, as revealed by data analysis and comparison of data for time before enforcement of restrictions. The Lockdown was announced after a 14 hour voluntary curfew, called Janata curfew, was observed on 22 March, after which CPCB had published a report titled "IMPACT OF JANTA CURFEW & LOCKDOWN ON AIR QUALITY" dated 31.03.2020, describing the improvement in air quality in the country. This report is in continuation to the same. The major sectors contributing to air pollution are transport, industries, power plants, construction activities, biomass & refuse burning, road dust resuspension and residential activities. In addition, certain activities such as operation of DG sets, restaurant, landfill fires, etc. also contribute to air pollution. Under the nationwide lockdown, all transport services – road, air and rail were suspended with exceptions for essential services. Educational institutions, industrial establishments and hospitality services were also suspended. As a result, air quality improvement has been noted in many towns and cities across the nation. During the lockdown period, as a result of combination of reduced vehicles on the road, functioning of only essential commercial units and prevailing weather conditions, significant reduction in PM2.5, PM10 and NO2 levels were observed. Overall, 46% reduction in PM2.5 and 50% reduction in PM10 was observed during the lockdown period. Similar level of reduction in PM10 & PM2.5 primarily indicate reduction in combustion and industrial sources which are common to both fractions of Particulate matter. Since 81% of Delhi's NOx comes from the transport sector (as per TERI Emission Inventory, 2018), restrictions on vehicular activity led to a 56% reduction in NO2 levels and over 37% reduction in CO levels during the lockdown period, compared pre- lockdown period.