Atmospheric Pollution Research 14 (2023) 101815 Available online 16 June 2023 1309-1042/© 2023 Turkish National Committee for Air Pollution Research and Control. Production and hosting by Elsevier B.V. All rights reserved. Black carbon temporal trends and associated health and economic impacts in Tehran Vahid Roostaei a , Sasan Faridi a, b , Fatemeh Momeniha c , Fatemeh Yousefian d , Adel Mokammel a, b , Sadegh Niazi e , Mohammad Sadegh Hassanvand a, b, * a Department of Environmental Health Engineering, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran b Center for Air Pollution Research (CAPR), Institute for Environmental Research (IER), Tehran University of Medical Sciences, Tehran, Iran c Center for Solid Waste Research (CSWR), Institute for Environmental Research, Tehran University of Medical Sciences, Tehran, Iran d Department of Environmental Health Engineering, Faculty of Health, Kashan University of Medical Sciences, Kashan, Iran e Queensland University of Technology (QUT), Faculty of Science, School of Earth and Atmospheric Sciences, International Laboratory for Air Quality and Health (ILAQH), Brisbane, 4000, Australia A R T I C L E INFO Keywords: Air pollution Black carbon Health impacts Economic loss Tehran Iran ABSTRACT Atmospheric black carbon (BC) particles resulting from the incomplete combustion of both fossil and non-fossil sources recently gained significant attention globally due to their potential health impacts. This study aimed to investigate the temporal trends of ambient BC in urban traffic (Sharif station) and background (Setad-e-Bohran station) air pollutants monitoring sites in Tehran, and to estimate its health and economic burdens from March 2017 to March 2018. The mean BC concentration in the traffic and urban background sites in cold seasons was 6.4 μg/m 3 and 3.4 μg/m 3 . During the warm season, these figures were 4.4 μg/m 3 and 2.3 μg/m 3 , respectively. Our observations indicated that ambient BC concentration was lower during weekends, more likely due to decreased traffic levels compared to weekdays. Our results showed that the concentration of BC and the BC/ PM 2.5 ratio were higher during nighttime in Tehran, likely due to high atmospheric stability and increased transit of heavy-duty diesel vehicles. We found strong correlation coefficients between BC, CO (BC–CO, r = 0.83, p < 0.01), NO 2 (BC– NO 2 , r = 0.64, p < 0.01), PM 2.5 (BC- PM 2.5 , r = 0.89, p < 0.01) and other components of PM 2.5 (BC- other components of PM 2.5 , r = 0.81, p < 0.01). We estimated that long-term exposure to ambient air BC resulted to 424 (95% Confidence Interval (CI): 400–510) deaths in adults ≥25 y/r from all-natural causes. Mortality due to BC exposure for ischemic heart disease, stroke, chronic obstructive pulmonary disease and lung cancer were 82, 28, 25, and 16, respectively. Exposure to BC caused an economic loss of 161.6 [95% CI: 105.5–213.8] million US$ due to all-cause mortality. Almost 11% of mortality and economic loss of PM 2.5 in Tehran is due to BC, which can be avoided by adopting and implementing appropriate and sustainable air quality abatements. 1. Introduction Exposure to ambient fine particulate matter (PM 2.5 ) emitted from natural and anthropogenic sources is associated with numerous adverse health eff ects, including pulmonary and cardiovascular diseases (Pau- nescu et al., 2019; Faridi et al., 2023). PM 2.5 is a heterogeneous mixture of aerosols, consisting of various components, including organic mate- rials, acids, and heavy metals (Janssen et al., 2011; Kirrane et al., 2019). Among the various components of PM 2.5 , atmospheric black carbon (BC) particles resulting from incomplete combustion have received signifi- cant global attention due to their potential impacts on health and contribution to global warming (Blanco-Alegre et al., 2019; Kirrane et al., 2019; Sahin et al., 2020). Atmospheric BC particles have a high toxicity potential due to their ability to penetrate pulmonary alveoli and further reaction with alveolar surfactant proteins and lipids (Lin et al., 2019; Liu et al., 2019; Paunescu et al., 2019; Peng et al., 2019). Similar to PM 2.5 , exposure to atmospheric BC particles over both short and long terms has been associated with subclinical cardiovascular and Peer review under responsibility of Turkish National Committee for Air Pollution Research and Control. * Corresponding author. Center for Air Pollution Research (CAPR), Institute for Environmental Research (IER) and Department of Environmental Health Engi- neering, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran. E-mail address: hassanvand@tums.ac.ir (M.S. Hassanvand). Contents lists available at ScienceDirect Atmospheric Pollution Research journal homepage: www.elsevier.com/locate/apr https://doi.org/10.1016/j.apr.2023.101815 Received 9 February 2023; Received in revised form 15 May 2023; Accepted 6 June 2023