The Environment and COVID-19 Transmission: A Perspective

Coronavirus disease 2019 (COVID-19) has become a severe public health threat worldwide. Despite the global spread, there is an observed aberration and skewness in the geographic/regional distribution of the disease, with a high preponderance of cases and mortality occurring in the temperate regions compared to the tropics. A plausible explanation for this discrepancy could be linked to variability in environmental factors. Hence, this review discusses succinctly the possible influences of geographic location, temperature/sunlight, relative humidity and building design on the rate of transmission of COVID-19. We postulate that elevated melatonin production in a hot climate, high temperature, adequate vitamin D synthesis from sunlight exposure, high relative humidity and efficient ventilation due to housing design confers innate immunity and adaptive advantage to COVID-19 transmission for populations in the tropics over those in the temperate regions. Hence, we recommend that control studies taking into congnizance the relationship between environment and disease be prioritized. Such studies are important for predicting viral disease spread, in particular if this leads to pandemics like in the case of COVID-19, to aid decisions in public health policies at the global level.