Impact of COVID-19 Pandemic on Particulate Matter (PM) concentration and harmful gaseous components on Indian metros

The COVID-19 pandemic has created a heartbreaking situation across the globe. It is affecting the human population both in terms of health issues and food safety concerns. Most of the countries are struggling to save their economies during the lock-down conditions. The fight against the COVID-19 is very tough; either one can save the economy or save his country's human population. It seems COVID-19 have all the negative impact across the world. However, there is also some positive impact of this pandemic, where we observe much reduced environmental pollution. There has been significant improvement in the air quality at almost all the places where lock-down is implemented. Air pollution directly affects our health and hence the quality of life. In India, air quality has improved much beyond our expectations during the lock-down. This paper studies the positive impact of the COVID-19 pandemic on air pollution in major Indian cities. In the air quality rating, the paper considers types of air pollutants like Particulate Matters and Gaseous Components as benchmarks. Authors have also used available literature to study the ongoing pollution measurements, impact, and change over time. The study analysed available air quality data of four metros, i.e., Delhi, Kolkata, Mumbai, and Chennai, over the four months (National Lockdown). Two particulate matters (PM-2.5 and PM-10) pollution levels are compared with last year's values to identify the significant variations. Moreover, Gaseous components are used to analyse their impact on the country's human health and food ecosystem. The study analyses the effect of COVID-19 on air pollution, and the general recommendations are given. Paper identifies that there is a very good or positive impact of closing polluting units and vehicular movements.