Environmental factors may play a role in susceptibility to infection and severe disease from SARS-CoV-2, the virus causing COVID-19. Using confirmed case and death data from the state of California in 2020, join UC Berkeley postdoctoral scholar, Helena Archer, MPH, PhD, as she discusses how she and her team studied the distribution of oil and gas wells and of two public water system contaminants and reported COVID-19 in California communities. Oil and gas production activities are a significant and underexamined source of pollution, including NO2 and PM2.5, and have been linked to respiratory and immunologic disease. Arsenic, a heavy metal, and nitrate, a chemical compound, are both naturally occurring substances that may be introduced or found in drinking sources, and have been linked to negative effects on human health and the immune system. In these two studies, they leveraged geographical and public data to examine whether residential exposure to these environmental hazards was associated with community-level COVID-19 case and mortality rates in the first year of the pandemic.