Abstract

Background and Aims: Latin America is one of the most urbanized areas of the world with nearly 80% of the population living in cities. Despite its benefits, this concentration of population in cities also increases exposures to pollutants related to urban activity. We examined levels and trends of PM2.5; patterns of population exposure by age, gender and socioeconomic status; disparities in exposure; and association of PM2.5 concentration with city characteristics and effects on mortality. Methods: Ground level annual PM2.5 from satellite-based observations was available in 2015 for 371 cities with greater than 100,000 residents and 1436 sub-city units across 11 countries in Latin America that comprise the SALURBAL Project (https://drexel.edu/lac/salurbal/overview/). Mortality, socio-demographic and built environment variables (patch density, intersection density, travel delay, density of subway, Bus Rapid Transit or other public transit, and area greenness) were examined using simple descriptive statistics and hierarchical linear mixed models. Results: Together, the included cities have approximately 300 million residents. Nearly 40% of the cities have mean PM2.5 concentration above the World Health Organization Air Quality Guidelines (AQG) (62% in Chile and 13% in Central America). Approximately 172 million people (including 12 million children aged 0-4) are potentially at risk for developing health problems due to AQG violations. There were no differences in exposure by gender and only small differences by SES. The elderly were proportionally more exposed. Levels of air pollution were associated with some built and socioenvironmental variables. From adjusted models we observed an increase of 1.5 (0.3 to 2.6) and 0.4 (0.1 to 0.8) in the mortality rate per 1.000.000 people for cardiovascular and respiratory diseases, for 1µg/m3 increase in mean PM2.5. Conclusions: High levels of air pollution exist in Latin America, are associated with city-level built and social environment characteristics, with detectable effects on mortality.