Differential Mortality Risks Associated With PM2.5 Components A Multi-Country, Multi-City Study

• Authors: Pierre Masselot, London School of Hygiene and Tropical Medicine (LSHTM); Francesco Sera, London School of Hygiene and Tropical Medicine (LSHTM); Rochelle Schneider, London School of Hygiene and Tropical Medicine (LSHTM); Haidong Kan, Fudan University; Éric Lavigne, University of Ottawa; Massimo Stafoggia, Lazio Regional Health Service/ASL Roma 1; Aurelio Tobias, Spanish Council for Scientific Research; Hong Chen, Health Canada, Ottawa; Richard T Burnett, Health Canada, Ottawa; Joel Schwartz, Harvard TH Chan School of Public Health; Antonella Zanobetti, Harvard TH Chan School of Public Health; Michelle L Bell, Yale University; Bing-Yu Chen, National Health Research Institutes; Yue-Liang Leon Guo, National Health Research Institutes; Martina S Ragettli, Swiss Tropical and Public Health Institute,; Ana Maria Vicedo-Cabrera, University of Bern; Christofer Åström, Umea University; Bertil Forsberg, Umea University; Carmen Íñiguez, University of Valencia; Rebecca M Garland, Council for Scientific and Industrial Research, South Africa; Noah Scovronick, Emory University; Joana Madureira, Instituto Nacional de Saúde Dr Ricardo Jorge; Baltazar Nunes, Instituto Nacional de Saúde Dr Ricardo Jorge; César De la Cruz Valencia, National Institute of Public Health, Mexico; Magali Hurtado Diaz, National Institute of Public Health, Mexico; Yasushi Honda, National Institute for Environmental Studies, Japan; Masahiro Hashizume, University of Tokyo; Chris Fook Cheng Ng, Nagasaki University; Evangelia Samoli, National and Kapodistrian University of Athens; Klea Katsouyanni, National and Kapodistrian University of Athens; Alexandra Schneider, German Research Center for Environmental Health (GmbH); Susanne Breitner, German Research Center for Environmental Health (GmbH); Niilo R Ryti, University of Oulu; Jouni JK Jaakkola, University of Oulu; Marek Maasikmets, Estonian Environmental Research Centre; Hans Orru, University of Tartu; Yuming Guo, Monash University; Nicolás Valdés Ortega, Universidad de los Andes; Patricia Matus Correa, Shanghai Jiao Tong University; Shilu Tong, Shanghai Jiao Tong University; Antonio Gasparrini, London School of Hygiene and Tropical Medicine (LSHTM)
• Journal Title: EPIDEMIOLOGY
• Volume: Volume 33, Number 2
• Publisher: LIPPINCOTT WILLIAMS & WILKINS | 2022-03-01, Pages 167-175
• Type of Work: Article | Post-print: After Peer Review
• Publisher DOI: http://doi.org/10.1097/EDE.0000000000001455
• Subjects: Health Sciences, Epidemiology; Health Sciences, Public Health
• Keywords: Science & Technology; Life Sciences & Biomedicine; Public, Environmental & Occupational Health; FINE PARTICULATE MATTER; AIR-POLLUTION; CHEMICAL-CONSTITUENTS; HOSPITAL ADMISSIONS; SHORT-TERM; CARDIOVASCULAR MORTALITY; R-PACKAGE; HEALTH; MODELS; EMISSIONS

Abstract

Background: The association between fine particulate matter (PM2.5) and mortality widely differs between as well as within countries. Differences in PM2.5 composition can play a role in modifying the effect estimates, but there is little evidence about which components have higher impacts on mortality. Methods: We applied a 2-stage analysis on data collected from 210 locations in 16 countries. In the first stage, we estimated location-specific relative risks (RR) for mortality associated with daily total PM2.5 through time series regression analysis. We then pooled these estimates in a meta-regression model that included city-specific logratio-transformed proportions of seven PM2.5 components as well as meta-predictors derived from city-specific socio-economic and environmental indicators. Results: We found associations between RR and several PM2.5 components. Increasing the ammonium (NH4+) proportion from 1% to 22%, while keeping a relative average proportion of other components, increased the RR from 1.0063 (95% confidence interval [95% CI] = 1.0030, 1.0097) to 1.0102 (95% CI = 1.0070, 1.0135). Conversely, an increase in nitrate (NO3-) from 1% to 71% resulted in a reduced RR, from 1.0100 (95% CI = 1.0067, 1.0133) to 1.0037 (95% CI = 0.9998, 1.0077). Differences in composition explained a substantial part of the heterogeneity in PM2.5 risk. Conclusions: These findings contribute to the identification of more hazardous emission sources. Further work is needed to understand the health impacts of PM2.5 components and sources given the overlapping sources and correlations among many components.