Association between air quality and COVID-19 infection case numbers

Abstract

BACKGROUND AND AIM: The coronavirus disease (COVID-19) has become a global pandemic affecting many countries, including Singapore. Previous studies have investigated the relationship of air pollutant levels with respiratory disease risk and hospital admission rates. However, associations between air pollutant concentrations and COVID-19 infection remains unclear. This study aimed to assess the association between core air pollutant concentrations and daily confirmed COVID-19 case numbers in Singapore. METHODS: Data on air pollutant levels (particulate matter [PM2.5, PM10], ozone [O3], carbon monoxide [CO], nitrogen dioxide [NO2], sulphur dioxide [SO2] and pollutant standards index [PSI]) was obtained from the Singapore National Environment Agency from January 23, 2020 to April 6, 2020. The daily reported COVID-19 case numbers were retrieved from the Singapore Ministry of Health. Generalized linear models with Poisson family distribution and log-link were used to estimate the coefficients and 95% confidence intervals (CIs) for the association between air pollutant concentrations with COVID-19 case numbers, adjusting for humidity, rainfall and day of week. RESULTS:We observed significantly positive associations between PM2.5, NO2 and PSI with COVID-19 case numbers. Every 1-unit increase (15-day MA) in PSI, 1 μg/m3 increase (15-day MA) in PM2.5 and NO2 were significantly associated with a 35.0% (95% CI: 29.7%–40.5%), 22.6% (95% CI: 12.0%–34.3%) and 34.8% (95% CI: 29.3%–40.4%) increase in the average daily number of COVID-19 cases respectively. On the contrary, PM10, O3, SO2, CO were significantly associated with lower average daily numbers of confirmed COVID-19 cases. CONCLUSIONS:Future studies could explore the long-term consequences of the air pollutants on COVID-19 infection and recovery. KEYWORDS: Air quality, COVID-19, Infection