Health impact and economic loss assessment of indoor PM2.5 pollution: A case during the COVID-19 lockdown period

Abstract

Indoor PM2.5 exposure is vital to accurately assess the health impacts and economic loss of ambient PM2.5 exposure. However, most previous studies have overlooked indoor PM2.5 and directly used outdoor PM2.5 concentration data as exposure concentrations to evaluate health impacts and economic losses, which could potentially lead to significant inaccuracies. In particular, since the COVID-19 outbreak, the Chinese government implemented a lockdown strategy that led to an increase in the time spent indoors. Here, we reveal the spatiotemporal characteristics of the health impacts and economic losses due to indoor PM2.5 pollution during the COVID-19 lockdown period in 2020. The bias induced by neglecting indoor PM2.5 pollution in assessing total health impacts and economic losses was calculated. The results showed that the annual average indoor PM2.5 concentration in China in 2020 was 18.16 μg/m3. The total health impact of indoor PM2.5 exposure in 2020 reached 8.1255 million people, and the economic loss of indoor PM2.5 exposure was 34,996 million USD, accounting for 0.24% of the national GDP. Compared to the period before the pandemic, the COVID-19 lockdown resulted in a 7.73% increase in health impacts and a 7.9% increase in economic losses associated with indoor PM2.5. Indoor pollution is the primary cause of PM2.5 pollution. The health impact and economic loss associated with indoor PM2.5 pollution accounting for 80.99% and 80.93% of the total impact and loss (caused by both indoor and outdoor PM2.5 pollution), respectively. If the indoor PM2.5 exposure concentrations were substituted with the ambient concentrations, the results would be overestimated by 76.22% and 77.11% for health impacts and health economic losses, respectively.