Compound effects of extreme heat and wildfire-PM2.5 air pollution on child hospitalizations in multiple countries
摘要
The compound effects of extreme heat events (EHEs) and high-level wildfire-sourced fine particulate matter (PM2.5) pollution (HFPP) on child hospitalization remain unclear. We applied quasi-Poisson regression and meta-analysis to investigate the short-term effects of EHE and HFPP on cause-specific hospitalizations among children and adolescents aged 19 years or younger, in Australia, Brazil, Canada, Chile and Thailand from 2000 to 2019. An EHE was defined as two or more consecutive days with a mean temperature greater than the 90th percentile. HFPP days were identified by PM2.5 > 15 µg m−3, with 50% or more contributed by wildfires. Here we show that compound exposure (days when EHE and HFPP co-occurred), was associated with a 3.8% elevated risk (relative risk = 1.038 (1.029‒1.048)) for all-cause hospitalization, higher than the individual risk, and varied according to disease subtypes, countries and subgroups. Significant synergistic effects, indicated by a positive relative excess risk due to interaction, exhibited for respiratory (0.028, 0.010‒0.047), renal (0.061, 0.013‒0.110) and diabetes (0.204, 0.073‒0.335) hospitalizations, stronger than relative excess risk because of the interaction of EHE and high-level non-fire PM2.5 pollution day. Generally, EHE and HFPP were associated with higher combined risks than EHE and high-level non-fire PM2.5 pollution day. Under a changing climate, understanding compound climate hazards, and disease-specific and demographic-specific vulnerabilities, is crucial for targeted adaptation efforts for susceptible paediatric populations.