Ke Ju, Rongbin Xu, Wenzhong Huang, Zhengyu Yang, Tingting Ye, Wenhua Yu, Yiwen Zhang, Bo Wen, Yao Wu, Pei Yu, Yanming Liu, Shuang Zhou, Gongbo Chen, Zhihu Xu, Michael Abramson, Guy Marks, Lidia Morawska, Fay H Johnston, Jane Heyworth, Geoffrey Morgan, Luke Knibbs, Simon Hales, Eric Lavigne, Paulo H N Saldiva, Micheline S Z S Coelho, Patricia Matus, Xerxes Seposo, Ho Kim, Yue Leon Guo, Kraichat Tantrakarnapa, Wissanupong Kliengchuay, Dung Phung, Jiangning Song, Shanshan Li, Yuming Guo
Short-term exposure to LF-PM2·5 was associated with substantial mortality and economic losses across diverse settings. The disproportionate contribution of LF-PM2·5 to PM2·5-attributable burden, together with the larger instrumental-variable estimates, suggests that traditional assessments might understate the consequences of landscape fire smoke.
BACKGROUND: Landscape fire-related fine particulate matter (LF-PM2·5) is associated with premature mortality. However, the mortality-related economic burden of LF-PM2·5 remains poorly quantified. We aimed to estimate the short-term effects of LF-PM2·5 on mortality and the associated economic losses.
METHODS: In this causal analysis, we linked daily mortality records from 1366 communities in ten countries and territories during 2000-19 to population-weighted LF-PM2·5 concentrations estimated from daily modelled data. Economic losses were estimated using adjusted values of a statistical life. We estimated community-specific associations using instrumental variable models and pooled them using random-effects meta-analysis. We compared instrumental variable estimates with traditional association estimates as well as corresponding estimates for non-LF-PM2·5.
FINDINGS: We analysed 47 844 851 deaths, corresponding to mortality-related economic losses valued at US$60·6 trillion. Each 1 μg/m3 increase in the 2-day moving average of LF-PM2·5 was associated with a 0·60% (95% CI 0·19-1·00) increase in mortality and a 0·59% (0·21-0·97) increase in economic losses. An estimated 906 869 deaths and $994·5 billion in economic losses were attributable to LF-PM2·5, with attributable fractions of 1·90% for deaths and 1·64% for economic losses. Traditional association estimates were found to be lower than instrumental variable estimates by a median of 56·0% (2·2-111·3) for mortality and 62·3% (9·0-116·1) for economic losses. LF-PM2·5 represented 19·0% of ambient PM2·5 mass but accounted for 30·6% of PM2·5-attributable deaths and 27·7% of PM2·5-attributable economic losses.
INTERPRETATION: Short-term exposure to LF-PM2·5 was associated with substantial mortality and economic losses across diverse settings. The disproportionate contribution of LF-PM2·5 to PM2·5-attributable burden, together with the larger instrumental-variable estimates, suggests that traditional assessments might understate the consequences of landscape fire smoke.
FUNDING: National Health and Medical Research Council, China Scholarship Council.