Association of mortality and combined oxidative capacity of ozone and nitrogen dioxide

Published on 15 June 2026 Updated on 10 July 2026

Ozone (O3) and nitrogen dioxide (NO2) are two common gaseous pollutants that both possess oxidizing properties with consequences for human health and have an inextricable chemical relationship that could have distinct public health impacts when considered in combination. We examined the short-term associations of the combined oxidative capacity of O3 and NO2 (represented by Oxwt, the average of O3 and NO2 concentrations weighted by their standard electrode potential) with total, cardiovascular and respiratory mortality in 380 cities across 23 countries or regions between 1985 and 2020. Over 2 days (LAG01), a 10-ppb increase in Oxwt concentration was associated with an increase of 0.82% (95% confidence interval (CI): 0.55%, 1.10%) in total mortality, 1.09% (95% CI: 0.83%, 1.35%) in cardiovascular mortality and 0.88% (95% CI: 0.31%, 1.45%) in respiratory mortality. We also observed variations in this association by geographic region and study period. More deaths were attributable to Oxwt than to either O3 or NO2 but fewer than the sum of the two. Thus, Oxwt might be a valuable indicator for use in public health efforts to capture the combined effects of O3 and NO2.

Author(s): Niu Yue, Chen Renjie, Sera Francesco, Urban Aleš, Vicedo-Cabrera Ana Maria, Honda Yasushi, Huber Veronika, Guo Yuming, Tong Shilu, Coelho Micheline de Sousa Zanotti Stagliorio, Saldiva Paulo Hilario Nascimento, Lavigne Eric, Matus Correa Patricia, Valdés Ortega Nicolás, Osorio Samuel, Achilleos Souzana, Roye Dominic, Jaakkola Jouni J. K, Ryti Niilo, Pascal Mathilde, Schneider Alexandra, Breitner-Busch Susanne, Entezari Alireza, Mayvaneh Fatemeh, Raz Raanan, Ng Chris Fook Sheng, Hashizume Masahiro, Carrasco Gabriel, das Neves Pereira da Silva Susana, Madureira Joana, Holobaca Iulian-Horia, Kim Ho, Lee Whanhee, Tobias Aurelio, Íñiguez Carmen, Guo Yue Leon, Pan Shih-Chun, Li Shanshan, Masselot Pierre, Bell Michelle L, Zanobetti Antonella, Schwartz Joel, Gasparrini Antonio, Kan Haidong

Publishing year: 2026

Pages: Online ahead of print

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