The association between COVID-19 deaths and short-term ambient air pollution/meteorological condition exposure: a retrospective study from Wuhan, China

The emergence of coronavirus disease 2019 (COVID-19) has become a worldwide pandemic after its first outbreak in Wuhan, China. However, it remains unclear whether COVID-19 death is linked to ambient air pollutants or meteorological conditions. We collected the daily COVID-19 death number, air quality index (AQI), ambient air pollutant concentrations, and meteorological variables data of Wuhan between Jan 25 and April 7, 2020. The Pearson and Poisson regression models were used accordingly to understand the association between COVID-19 deaths and each risk factor. The daily COVID-19 deaths were positively correlated with AQI (slope = 0.4 ± 0.09, R2 = 0.24, p < 0.01). Detailedly, PM2.5 was the only pollutant exhibiting a positive association (relative risk (RR) = 1.079, 95%CI 1.071–1.086, p < 0.01) with COVID-19 deaths. The PM10, SO2, and CO were all also significantly associated with COVID-19 deaths, but in negative pattern (p < 0.01). Among them, PM10 and CO had the highest and lowest RR, which equaled to 0.952 (95%CI 0.945–0.959) and 0.177 (95%CI 0.131–0.24), respectively. Additionally, temperature was inversely associated with COVID-19 deaths (RR = 0.861, 95%CI 0.851–0.872, p < 0.01). Contrarily, diurnal temperature range was positively associated with COVID-19 deaths (RR = 1.014, 95%CI 1.003–1.025, p < 0.05). The data suggested that PM2.5 and diurnal temperature range are tightly associated with increased COVID-19 deaths.