Atmospheric particulate matter effects on Sars-Cov-2 infection and its dynamics spreading: a spatio-temporal point process model

Background and Aim: Particulate matter (PM) may play a role in differential distribution and transmission rates of SARS-CoV-2. Identification of factors affecting the transmission dynamics concerning the endemic (persistent sporadic) and epidemic (rapidly clustered) component of infection can helps to implement intervention strategies to reduce the disease burden. Aim of this study is to assess the effect of long-term residential exposure to PM on Sars-Cov-2 incidence and on the dynamics of infectious disease spreading in Marche Region (Central Italy). Methods: All individuals with first positive SARS-CoV-2 molecular test from February to May 2020, residing in the Marche region were analysed along with gender, age, employment, Nursing Homes and Long-Term Care Facilities (NH-LTCF) residence and socio-economic deprivation index (DI); long-term exposure to outdoor PM ≤ 10 μm (PM10) concentrations, Temperature and Relative Humidity were estimated at 10 km2 grid cells. The endemic-epidemic spatio-temporal regression model for individual-level data was used to identify factors influencing SARS-CoV-2 spreading and its infectious rate. Rate ratios (RR) and 95% confidence intervals (CI) were calculated. Results: 10-years average exposure to PM10 was associated with an increased risk of new endemic (RR 1.14, 95%CI 1.04-1.24) and epidemic (RR 1.15, 95%CI 1.08-1.22) infectious. Male gender, older age, living in NH-LTCF and the worsening of DI increased RR in epidemic component. Lockdown increase the risk of becoming positive to Sars-Cov2 as concerning endemic while it reduces virus spreading in epidemic component. Increased temperature was associated with a reduction of endemic and epidemic infectious. Conclusions: Results show an increment of RR for exposure to increased levels of PM10 both in endemic and epidemic components. Targeted interventions are necessary to improve air quality in most polluted areas to minimize the burden of endemic and epidemic COVID-19 disease and to reduce unequal distribution of health risk. Keywords: air polltuion, Sars-Cov2, infectious disease