Ambient fine particulate matter (PM2.5) is described as a major global health issue (WHO, 2022, Hofflinger et al., 2019). Particulate matter is a convenient measure of air pollution, because it includes particles formed by a variety of processes that may be human-made (e.g., smoke and soot from combustion) or natural (e.g., volcanic ash, sea spray). Pollutants in the air tend to aggregate into particles of similar or dissimilar molecules, and when large aggregates are formed they may fall to the ground in a process known as sedimentation (Vallero, 2014). The literature describes the associations of PM2.5 with respiratory and heart diseases (Pope & Dockery, 2006), cancer (Demetriou et al., 2012), diabetes (Eze et al., 2017), inflammation (Pope & Dockery, 2006), stress (Li et al., 2003), dementia (Tonne et al., 2013), as well as numerous effects on eyes, skin, hair, liver, bones, etc. (Gautam & Bolia, 2020). Air pollution also brings social and economic impacts, related to visibility, academic performance, housing prices, climate, etc. (Chen & Jin, 2019; Feng et al., 2019; Gautam & Bolia, 2020), and residents’ happiness (Zhang et al., 2017).
Population exposure to air pollution is measured by assessing the weighted average value of PM2.5 present in each region, with the weight given by the estimated population count in each cell (OECD, 2022). Monthly PM2.5 concentrations can be received from ground measurements of these pollutants, meteorological reports, or satellite remote sensing data (Chen et al., 2021).