Short-term effects of fine particulate matter pollution on daily health events in Latin America: a systematic review and meta-analysis

Objectives Ambient air pollution is among the leading risks for health worldwide and by 2050 will largely overcome deaths due to unsafe sanitation and malaria, but local evidence from Latin America (LA) is scarce. We aimed to summarize the effect of short-term exposure to fine particulate air pollution (PM 2.5 ) on morbidity and mortality in Latin America and evaluate evidence coverage and quality, using systematic review and meta-analysis. Methods The comprehensive search (six online databases and hand-searching) identified studies investigating the short-term associations between PM 2.5 and daily health events in LA. Two reviewers independently accessed the internal validity of the studies and used random-effect models in the meta-analysis. Results We retrieved 1628 studies. Nine were elected for the qualitative analysis and seven for the quantitative analyses. Each 10 µg/m 3 increments in daily PM 2.5 concentrations was significantly associated with increased risk for respiratory and cardiovascular mortality in all-ages (polled RR = 1.02, 95% CI, 1.02–1.02 and RR = 1.01, 95% CI , 1.01–1.02, respectively). Conclusions Short-term exposure to PM 2.5 in LA is significantly associated with increased risk for respiratory and cardiovascular mortality. Evidence is concentrated in few cities and some presented high risk of bias.