Non-negligible contributions to human health from increased household air pollution exposure during the COVID-19 lockdown in China

Abstract

Our study indicates that lockdown measures in China led to abrupt reductions in ambient PM_2.5 concentration but also led to significant increases in indoor PM_2.5 exposure due to confined indoor activities and increased usages of household fuel for cooking and heating. We estimated that hundreds of premature deaths were added as a combination of decreased ambient PM_2.5 and increased household PM_2.5. Our findings suggest that the reduction in ambient PM_2.5 was negated by increased exposure to household air pollution, resulting in an overall increase in integrated population weighted exposure. Although lockdown measures were instrumental in reducing the exposure to pollution concentration in cities, rural areas bore the brunt, mainly due to the use of dirty solid fuels, increased population density due to the large-scale migration of people from urban to rural areas during the Chinese New Year and long exposure time to HAP due to restrictions in outdoor movement.