Klea Katsouyanni, Antonella Zanobetti, Hans Orru, Cong Liu, Masahiro Hashizume, Patricia Matus Correa, Baltazar Nunes, Jan Kyselý, Chris Fook Sheng Ng, Aurelio Tobias, Martina S. Ragettli, Yuming Guo, Tangchun Wu, Shanshan Li, Ana M. Vicedo-Cabrera, Christofer Åström, Ho Kim, Marek Maasikmets, Aleš Urban, Shilu Tong, Bertil Forsberg, Haidong Kan, Yasushi Honda, João Paulo Teixeira, Yueliang Leon Guo, Niilo R.I. Ryti, Francesco Sera, Iulian Horia Holobaca, Ai Milojevic, Xia Meng, Antonis Analitis, Alexandra Schneider, Micheline de Sousa Zanotti Stagliorio Coelho, Michelle L. Bell, Eric Lavigne, Veronika Huber, Simona Fratianni, Renjie Chen, Jouni J. K. Jaakkola, Antonio Gasparrini, Paulo Hilário Nascimento Saldiva, Shih-Chun Pan, Carmen Iñiguez, Samuel Osorio, Nicolas Valdes Ortega, Garcia, Joel Schwartz, Instituto de Saúde Pública da Universidade do Porto, Tobías, Aurelio [0000-0001-6428-6755], and Tobías, Aurelio
Objective To evaluate the short term associations between nitrogen dioxide (NO2) and total, cardiovascular, and respiratory mortality across multiple countries/regions worldwide, using a uniform analytical protocol. Design Two stage, time series approach, with overdispersed generalised linear models and multilevel meta-analysis. Setting 398 cities in 22 low to high income countries/regions. Main outcome measures Daily deaths from total (62.8 million), cardiovascular (19.7 million), and respiratory (5.5 million) causes between 1973 and 2018. Results On average, a 10 μg/m3 increase in NO2 concentration on lag 1 day (previous day) was associated with 0.46% (95% confidence interval 0.36% to 0.57%), 0.37% (0.22% to 0.51%), and 0.47% (0.21% to 0.72%) increases in total, cardiovascular, and respiratory mortality, respectively. These associations remained robust after adjusting for co-pollutants (particulate matter with aerodynamic diameter ≤10 μm or ≤2.5 μm (PM10 and PM2.5, respectively), ozone, sulfur dioxide, and carbon monoxide). The pooled concentration-response curves for all three causes were almost linear without discernible thresholds. The proportion of deaths attributable to NO2 concentration above the counterfactual zero level was 1.23% (95% confidence interval 0.96% to 1.51%) across the 398 cities. Conclusions This multilocation study provides key evidence on the independent and linear associations between short term exposure to NO2 and increased risk of total, cardiovascular, and respiratory mortality, suggesting that health benefits would be achieved by tightening the guidelines and regulatory limits of NO2., HaK was supported by the National Natural Science Foundation of China (92043301, 82030103, and 91843302) and China Medical Board Collaborating Program (16-250). AG and FS were supported by the Medical Research Council, UK (MR/M022625/1), the Natural Environment Research Council, UK (NE/R009384/1), and the European Union’s Horizon 2020 Project Exhaustion (820655). VH was supported by the Spanish Ministry of Science and Innovation (PCIN-2017-046), and the German Federal Ministry of Education and Research (01LS1201A2). YH and MH were supported by the Environment Research and Technology Development Fund (JPMEERF15S11412) of the Environmental Restoration and Conservation Agency, Japan. JK and AU were supported by the Czech Science Foundation (18-22125S). ST was supported by the Shanghai Municipal Science and Technology Commission (18411951600). Y-LLG was supported by a Career Development Fellowship of the Australian National Health and Medical Research Council (APP1163693). SL was supported by an Early Career Fellowship of the Australian National Health and Medical Research Council (APP1109193). JJKJJ and NR were supported by the Academy of Finland (310372). The funders had no role in considering the study design or in the collection, analysis, interpretation of data, writing of the report, or decision to submit the article for publication.