Background: Several countries have documented the relationship between long-term exposure to air pollutants and epidemiological indicators of the COVID-19 pandemic, such as incidence and mortality. This study aims to explore the association between air pollutants, such as PM_2.5 and PM₁₀, and the incidence and mortality rates of COVID-19 during 2020. Methods: The incidence and mortality rates were estimated using the COVID-19 cases and deaths from the Chilean Ministry of Science, and the population size was obtained from the Chilean Institute of Statistics. A chemistry transport model was used to estimate the annual mean surface concentration of PM_2.5 and PM₁₀ in a period before the current pandemic. Negative binomial regressions were used to associate the epidemiological information with pollutant concentrations while considering demographic and social confounders. Results: For each microgram per cubic meter, the incidence rate increased by 1.3% regarding PM_2.5 and 0.9% regarding PM₁₀. There was no statistically significant relationship between the COVID-19 mortality rate and PM_2.5 or PM₁₀. Conclusions: The adjusted regression models showed that the COVID-19 incidence rate was significantly associated with chronic exposure to PM_2.5 and PM₁₀, even after adjusting for other variables.

Arica is a coastal city located in northern Chile, in the Atacama Desert. The behavior of surface temperatures in the city between 1985 and 2019 was studied using Landsat satellite images, leading to the identification of surface urban heat islands (SUHI), surface urban cold islands (SUCI), and average temperature zones. The higher intensities of the SUHI reach values of almost 45 °C and the SUCI lower values are below 13 °C. From the socioeconomic characterisation of the population based on indicators retrieved from the 2012 and 2017 population censuses, we identified that during the study period there was a lower presence of SUHI, but these were linked to spaces of lower socioeconomic level and, for the most part, would form new urban spaces within the city. On the other hand, SUCI had a greater spatial presence in the study area and in the urban morphology, being found mostly in areas of high socioeconomic level and in consolidated spaces with few possibilities of generating new constructions.