A city-level analysis of air pollution, climate and COVID-19 early spread during the Spanish lockdown

Briz-Redon, A.; Belenguer-Sapina, C.; Serrano-Aroca, A.

The COVID-19 outbreak has escalated into the worse pandemic of the present century. The rapid spread of the new SARS-CoV-2 coronavirus has caused devastating health and economic crises all over the world, with Spain being one of the worst affected countries in terms of confirmed COVID-19 cases and deaths per inhabitant. In this situation, the Spanish Government declared the lockdown of the country with the aim of flattening the epidemic curve. The variations of air pollution in terms of fine particulate matter (PM2.5) levels in 8 cities of Spain are analyzed here considering the effect of meteorology during the COVID-19 lockdown period (from March 15th to April 12th 2020). The results of the analysis show that the 4-week Spanish lockdown was not long enough to reduce the PM2.5 levels in all the cities considered. These reductions were less than those expected, despite the drastically reduced human activity. Furthermore, no associations between COVID-19 accumulated cases and PM2.5 exposure or environmental conditions (temperature, precipitation, wind speed, sunlight hours, maximum pressure) were found during the early spread of the pandemic.