Health risks and lag effects of ambient PM2.5 exposure on respiratory and cardiovascular mortality and morbidity in Ratchaburi, Thailand

Exposure to ambient PM 2.5 is a well-established environmental risk factor associated with adverse respiratory and cardiovascular health outcomes. Ratchaburi, Thailand, has experienced increasing concerns regarding ambient PM 2.5 pollution. This study investigated the associations between ambient PM 2.5 exposure and respiratory and cardiovascular mortality and morbidity in Ratchaburi from 2015 to 2019 using a distributed lag non-linear model (DLNM). The exposure–lag–response relationships were assessed on the current day of exposure and up to seven days following exposure. For all ages and all genders, a 10 µg/m³ increase in PM 2.5 was associated with a 5.42% (95% CI 1.85–9.12%) increase in respiratory mortality at lag0, and a 2.69% (95% CI 1.45–3.95%) increase in respiratory morbidity at lag0-6. Cardiovascular mortality increased by 3.55% (95% CI 0.23–6.99%) at lag0-5 and cardiovascular morbidity by 1.85% (95% CI − 0.24–3.98%) at lag0-6. The observed associations varied across age and gender categories. Elderly individuals generally showed higher risks for respiratory mortality, while adults showed higher risks for respiratory morbidity and cardiovascular mortality. Females generally showed higher associations for respiratory and cardiovascular morbidity, whereas males showed higher associations for cardiovascular mortality. Overall, the findings provide local epidemiological evidence regarding short-term PM 2.5 exposure and associated respiratory and cardiovascular health burdens in Ratchaburi, Thailand. The observed exposure–lag–response relationships support future public health planning and air quality management strategies related to PM 2.5 exposure in areas experiencing elevated PM 2.5 concentrations.