Assessment of weather and atmospheric pollution as a co-factor in the spread of SARS-CoV-2

BACKGROUND AND AIM: COVID-19 is a persistent and ongoing global pandemic caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Non-anthropogenic factors, such as weather conditions and air quality are possible predictors of respiratory diseases, such as COVID-19. Weather conditions may also be a direct cause of biological interactions between SARS-CoV-2 and humans and vary widely between regions. The course of an epidemic is determined by several factors, including demographic and environmental parameters, many of which have an unknown correlation with COVID-19. The goal of this study is to access the influence of ground surface particulate matter and weather parameters on the dissemination of COVID-19 in Ljubljana, Slovenia. METHODS: Data on average, minimum and maximum daily temperature, relative humidity; precipitation; sun duration in hours; and daily particle matter (PM10 and PM2.5) was obtained from the Slovenian Environmental Agency. The dataset on the number of daily COVID-19 cases in Ljubljana was obtained from the National Institute of Public Health. Data was divided into three groups: entire dataset; partial lifting of measures (from 1st of June to 30th of September); and less stringent containment measures (from 1st of July to 30th of September). Spearman rank correlation was used to investigate the association between new daily COVID-19 cases and weather data. RESULTS: The weather data and the daily new COVID -19 cases did not show any significant correlation during the entire period under investigation, except for PM 10 (0.30). With the beginning of the less stringent containment measures, five of the six weather parameters correlated significantly with the daily cases of COVID-19. Relative humidity showed the highest correlation coefficient (0.48). CONCLUSIONS: The correlations observed are highly dependent on the local policies that were in force during the period under study. The interaction between weather conditions and human behaviour may also be an important factor in understanding the relationship between weather and the spread of COVID -19. (www.actabiomedica.it)