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.Two stage, time series approach, with overdispersed generalised linear models and multilevel meta-analysis.398 cities in 22 low to high income countries/regions.Daily deaths from total (62.8 million), cardiovascular (19.7 million), and respiratory (5.5 million) causes between 1973 and 2018.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.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.
Xia Meng, Cong Liu, Renjie Chen, Francesco Sera, Ana Maria Vicedo-Cabrera, Ai Milojevic, Yuming Guo, Shilu Tong, Micheline de Sousa Zanotti Stagliorio Coelho, Paulo Hilario Nascimento Saldiva, Eric Lavigne, Patricia Matus Correa, Nicolas Valdes Ortega, Samuel Osorio, Garcia, Jan Kyselý, Aleš Urban, Hans Orru, Marek Maasikmets, Jouni J K Jaakkola, Niilo Ryti, Veronika Huber, Alexandra Schneider, Klea Katsouyanni, Antonis Analitis, Masahiro Hashizume, Yasushi Honda, Chris Fook Sheng Ng, Baltazar Nunes, João Paulo Teixeira, Iulian Horia Holobaca, Simona Fratianni, Ho Kim, Aurelio Tobias, Carmen Íñiguez, Bertil Forsberg, Christofer Åström, Martina S Ragettli, Yue-Liang Leon Guo, Shih-Chun Pan, Shanshan Li, Michelle L Bell, Antonella Zanobetti, Joel Schwartz, Tangchun Wu, Antonio Gasparrini, Haidong Kan