BACKGROUND: Evidence on the potential interactive effects of heat and ambient air pollution on cause-specific mortality is inconclusive and limited to selected locations. OBJECTIVES: We investigated the effects of heat on cardiovascular and respiratory mortality and its modification by air pollution during summer months (six consecutive hottest months) in 482 locations across 24 countries. METHODS: Location-specific daily death counts and exposure data (e.g., particulate matter with diameters ≤ 2.5 µm [PM(2.5)]) were obtained from 2000 to 2018. We used location-specific confounder-adjusted Quasi-Poisson regression with a tensor product between air temperature and the air pollutant. We extracted heat effects at low, medium, and high levels of pollutants, defined as the 5th, 50th, and 95th percentile of the location-specific pollutant concentrations. Country-specific and overall estimates were derived using a random-effects multilevel meta-analytical model. RESULTS: Heat was associated with increased cardiorespiratory mortality. Moreover, the heat effects were modified by elevated levels of all air pollutants in most locations, with stronger effects for respiratory than cardiovascular mortality. For example, the percent increase in respiratory mortality per increase in the 2-day average summer temperature from the 75th to the 99th percentile was 7.7% (95% Confidence Interval [CI] 7.6-7.7), 11.3% (95%CI 11.2-11.3), and 14.3% (95% CI 14.1-14.5) at low, medium, and high levels of PM(2.5), respectively. Similarly, cardiovascular mortality increased by 1.6 (95%CI 1.5-1.6), 5.1 (95%CI 5.1-5.2), and 8.7 (95%CI 8.7-8.8) at low, medium, and high levels of O(3), respectively. DISCUSSION: We observed considerable modification of the heat effects on cardiovascular and respiratory mortality by elevated levels of air pollutants. Therefore, mitigation measures following the new WHO Air Quality Guidelines are crucial to enhance better health and promote sustainable development.
Auteur : Rai Masna, Stafoggia Massimo, de'Donato Francesca, Scortichini Matteo, Zafeiratou Sofia, Vazquez Fernandez Liliana, Zhang Siqi, Katsouyanni Klea, Samoli Evangelia, Rao Shilpa, Lavigne Eric, Guo Yuming, Kan Haidong, Osorio Samuel, Kyselý Jan, Urban Ales, Orru Hans, Maasikmets Marek, Jaakkola Jouni J K, Ryti Niilo, Pascal Mathilde, Hashizume Masahiro, Fook Sheng Ng Chris, Alahmad Barrak, Hurtado Diaz Magali, De la Cruz Valencia César, Nunes Baltazar, Madureira Joana, Scovronick Noah, Garland Rebecca M, Kim Ho, Lee Whanhee, Tobias Aurelio, Íñiguez Carmen, Forsberg Bertil, Åström Christofer, Maria Vicedo-Cabrera Ana, Ragettli Martina S, Leon Guo Yue-Liang, Pan Shih-Chun, Li Shanshan, Gasparrini Antonio, Sera Francesco, Masselot Pierre, Schwartz Joel, Zanobetti Antonella, Bell Michelle L, Schneider Alexandra, Breitner Susanne
Environment international, 2023, vol. 174, p. 107825
