Author(s):
Chen, Gongbo ; Guo, Yuming ; Yue, Xu ; Xu, Rongbin ; Yu,Wenhua ; Ye, Tingting ; Tong, Shilu ; Gasparrini, Antonio ; Bell,Michelle L. ; Armstrong, Ben ; Schwartz, Joel ; Jaakkola, Jouni J.K. ; Lavigne, Eric ; Saldiva, Paulo Hilario Nascimento ; Kan, Haidong ; Royé, Dominic ; Urban, Aleš ; Vicedo-Cabrera, Ana Maria ; Tobias, Aurelio ; Forsberg, Bertil ; Sera, Francesco ; Lei, Yadong ; Abramson, Michael J. ; Li, Shanshan ; Abrutzky, Rosana ; Alahmad, Barrak ; Ameling, Caroline ; Åström, Christofer ; Breitner, Susanne ; Carrasco-Escobar, Gabriel ; Coêlho, Micheline de Sousa Zanotti Stagliorio ; Colistro, Valentina ; Correa, Patricia Matus ; Dang, Tran Ngoc ; de'Donato, Francesca ; Dung, Do Van ; Entezari, Alireza ; Garcia, Samuel David Osorio ; Garland, Rebecca M. ; Goodman, Patrick ; Guo, Yue Leon ; Hashizume, Masahiro ; Holobaca, Iulian-Horia ; Honda, Yasushi ; Houthuijs, Danny ; Hurtado-Díaz, Magali ; Íñiguez, Carmen ; Katsouyanni, Klea ; Kim, Ho ; Kyselý, Jan ; Lee, Whanhee ; Maasikmets, Marek ; Madureira, Joana ; Mayvaneh, Fatemeh ; Nunes, Baltazar ; Orru, Hans ; Ortega, Nicol´s Valdés ; Overcenco, Ala ; Pan, Shih-Chun ; Pascal, Mathilde ; Ragettli, Martina S. ; Rao, Shilpa ; Ryti, Niilo R.I. ; Samoli, Evangelia ; Schneider, Alexandra ; Scovronick, Noah ; Seposo, Xerxes ; Stafoggia, Massimo ; Valencia, César De la Cruz ; Zanobetti, Antonella ; Zeka, Ariana ; behalf of the Multi-Country Multi-City Collaborative Research Network
Date: 2024
Persistent ID: http://hdl.handle.net/10400.18/10347
Origin: Repositório Científico do Instituto Nacional de Saúde
Subject(s): MCC; Mortality; All-cause; Respiratory; Cardiovascular; Wildfire-related Ozone; Determinantes da Saúde e da Doença; Avaliação do Risco
Description
Background: Wildfire activity is an important source of tropospheric ozone (O3) pollution. However, no study to date has systematically examined the associations of wildfire-related O3 exposure with mortality globally. Methods: We did a multicountry two-stage time series analysis. From the Multi-City Multi-Country (MCC) Collaborative Research Network, data on daily all-cause, cardiovascular, and respiratory deaths were obtained from 749 locations in 43 countries or areas, representing overlapping periods from Jan 1, 2000, to Dec 31, 2016. We estimated the daily concentration of wildfire-related O3 in study locations using a chemical transport model, and then calibrated and downscaled O3 estimates to a resolution of 0·25° × 0·25° (approximately 28 km2 at the equator). Using a random-effects meta-analysis, we examined the associations of short-term wildfire-related O3 exposure (lag period of 0-2 days) with daily mortality, first at the location level and then pooled at the country, regional, and global levels. Annual excess mortality fraction in each location attributable to wildfire-related O3 was calculated with pooled effect estimates and used to obtain excess mortality fractions at country, regional, and global levels. Findings: Between 2000 and 2016, the highest maximum daily wildfire-related O3 concentrations (≥30 μg/m3) were observed in locations in South America, central America, and southeastern Asia, and the country of South Africa. Across all locations, an increase of 1 μg/m3 in the mean daily concentration of wildfire-related O3 during lag 0-2 days was associated with increases of 0·55% (95% CI 0·29 to 0·80) in daily all-cause mortality, 0·44% (-0·10 to 0·99) in daily cardiovascular mortality, and 0·82% (0·18 to 1·47) in daily respiratory mortality. The associations of daily mortality rates with wildfire-related O3 exposure showed substantial geographical heterogeneity at the country and regional levels. Across all locations, estimated annual excess mortality fractions of 0·58% (95% CI 0·31 to 0·85; 31 606 deaths [95% CI 17 038 to 46 027]) for all-cause mortality, 0·41% (-0·10 to 0·91; 5249 [-1244 to 11 620]) for cardiovascular mortality, and 0·86% (0·18 to 1·51; 4657 [999 to 8206]) for respiratory mortality were attributable to short-term exposure to wildfire-related O3. Interpretation: In this study, we observed an increase in all-cause and respiratory mortality associated with short-term wildfire-related O3 exposure. Effective risk and smoke management strategies should be implemented to protect the public from the impacts of wildfires.
Research in context - Evidence before this study: Unprecedented wildfires have been occurring in many locations globally. Air pollution from wildfires has become a considerable public health concern, given the various adverse effects on health. According to previous research, air pollution from wildfire sources is significantly linked to an increased risk of death. To ascertain the latest evidence from Jan 1, 2000, to June 25, 2023, we did a systematic search on Google Scholar, Web of Science, and PubMed, using the following terms: (“wildfire” or “bushfire” or “fire”) and (“ozone” or “O3”) and (“mortal*” or “fatal*” or “death*” or “dead*“). The language of publications was restricted to English and Chinese. Our search yielded a small number of studies investigating the impact of wildfire-related O3 exposure on mortality. These studies showed statistically significant links between O3 from wildfires and increased hospital admissions or mortality. However, the current evidence largely originates from localised or regional studies, with a notable absence of comprehensive assessments across regions globally. Added value of this study: To our knowledge, this study is the first to systematically evaluate the associations of short-term wildfire-related O3 exposure with daily mortality across various regions and populations globally. We collected daily counts of all-cause, cardiovascular, and respiratory deaths from up to 749 locations in 43 countries or areas between 2000 and 2016. The daily concentration of O3 from wildfire sources in study locations was estimated with a 3D GEOS-Chem model. We first examined the associations of short-term wildfire-related O3 exposure with daily mortality at the location level, and then pooled results at the country, regional, and global levels via a random-effects meta-analysis. Across all locations, we found that short-term exposure to wildfire-related O3 was associated with significant percentage increases in daily all-cause and respiratory mortality. No such significant increase was found for daily cardiovascular mortality. Implications of all the available evidence: Based on multicountry assessment of exposure, this study presents epidemiological evidence showing an excess of deaths linked to short-term exposure to wildfire-related O3. Effective risk management is required from policy makers and public health experts, involving actions to reduce exposure to wildfires.
