Ambient air pollution is a major environmental health risk, with impacts that may be unevenly distributed across vulnerable populations, particularly in urban areas under changing climate conditions. This study assessed whether social conditions modify the association between exposure to fine particulate matter (PM2.5) and deaths from circulatory and respiratory diseases in Campinas, Brazil. An ecological time-series study was conducted from 2010 to 2023 using monthly death data aggregated at the catchment-area level of 63 Primary Health Care Centers, stratified into four vulnerability groups. Associations between monthly PM2.5 concentrations and mortality rates were estimated using distributed lag non-linear models within a generalized additive modeling framework, adjusting for meteorological variables, ozone, seasonality, and long-term trends. A total of 38,311 cardiorespiratory deaths were recorded. Mortality rates varied non-linearly across strata, and a statistically significant positive association between PM2.5 exposure and mortality was observed only in the intermediate–high vulnerability group at higher pollution levels. No significant associations were identified in the lowest or highest vulnerability strata. These findings indicate that social context modifies air pollution–related mortality risks, highlighting the importance of incorporating vulnerability dimensions into air quality assessments and climate-related public health strategies.
Kassada et al. (Sat,) studied this question.