Health impact assessment of ambient fine particulate matter 2.5 (PM 2.5 ) decline during COVID-19 movement restrictions, India

Abstract Objective To quantify avoidable deaths in five Indian megacities associated with reductions in ambient levels of particulate matter 2.5 µm or less in diameter (PM 2.5 ) during two coronavirus disease 2019 (COVID-19) movement restrictions. Methods We obtained data from United States’ Embassy and Consulate monitors on PM 2.5 concentrations in Chennai, Hyderabad, Kolkata, Mumbai and New Delhi during the first (25 March to 31 May 2020) and second (5 April to 15 June 2021) COVID-19 movement restrictions. We used the World Health Organization’s AirQ+ tool to estimate the annual number of PM 2.5 -associated avoidable deaths over the long term due to all causes, chronic obstructive pulmonary disease, lung cancer, ischaemic heart disease and stroke in adults and due to acute lower respiratory infection in young children. Findings Mean PM 2.5 concentrations across the five cities decreased by 28– 77% during the first movement restriction and by 48–69% during the second movement restriction. During the first movement restriction alone, decreases in PM 2.5 were associated with an estimated 132□000 fewer annual deaths from all causes across the five cities and with 11□100, 3900, 5500, 3900 and 1240 fewer annual deaths due to chronic obstructive pulmonary disease, lung cancer, ischaemic heart disease, stroke and acute lower respiratory infection, respectively. Conclusion Improvements in air quality equivalent to those observed during COVID-19 movement restrictions in Indian megacities could save hundreds of thousands of lives annually. Higher air quality standards and aggressive mitigation and enforcement measures are needed to reduce mortality due to air pollution.