Contents lists available at ScienceDirect Environmental Toxicology and Pharmacology journal homepage: www.elsevier.com/locate/etap Research paper Effects of 1,4-naphthoquinone aged carbon black particles on the cell membrane of human bronchial epithelium Yongming Zhang a,b,1 , Li Wang a,1 , Huimin Feng b , Guiping Hu b , Lele Wang b , Jiaxing Liu b , Xin Gao b , Jing Shang c , Tong Zhu c , Shichuan Tang d , Guang Jia b, ⁎ a Department of Occupational and Environmental Health Science, School of Public Health, Baotou Medical College, Baotou, Inner Mongolia Autonomous Region 014030, China b Department of Occupational and Environmental Health Science, School of Public Health, Peking University, Beijing 100191, China c State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China d Beijing Key Laboratory of Occupational Safety and Health, Beijing, 100054, China ARTICLE INFO Keywords: Carbon black 1,4-naphthoquinone Cytotoxicity Cell membrane fluidity Cell membrane permeability Cell membrane potential ABSTRACT Black carbon (BC) and polycyclic aromatic hydrocarbons (PAHs), which are major atmospheric pollutants in China, are hazardous to humans following inhalation. BC can be oxidized by PAHs forming secondary particles of which the health effects are unknown. In this study, carbon black (CB) was used to simulate BC to reveal the adverse effects of 1,4-naphthoquinone aged carbon black (CB/1,4-NQ) particles on the membrane of human bronchial epithelial (16HBE) cells. It was showed that, the cell viability, cell membrane fluidity, membrane potential and mitochondrial membrane potential were significantly decreased after 16HBE cells were treated with CB, 1,4-NQ or CB/1,4-NQ. Meanwhile, the cell membrane permeability and intracellular Ca 2+ con- centration were increased. CB/1,4-NQ could induce more adverse effects on cell membrane than single CB treated, while less than 1,4-NQ. The results indicated that CB/1,4-NQ particles in the atmosphere may cause more damage to health, and the effects on cell membrane can be used to evaluate the early health effects of the particulate matter exposure. 1. Introduction The middle and eastern part of China have suffered from haze for many years. The air pollution is widespread and long-lasting, which has been acknowledged to be a serious public health problem (Pan., 2015). The fine particulate matter (PM 2.5 ) is one of the major components of the air pollution. It is composed of newly generated primary particles as well as secondary particles. It has been showed that the secondary particles are formed from a series of physical and chemical processes, such as adsorption, photochemical reactions and heterogeneous reac- tions, etc. (Ye and Chen, 2009). In the context of urban complex pol- lution in China, atmospheric oxidation is increasing and the secondary particulate pollution is getting serious. Moreover, the proportion of secondary particles has increased to 30%–77% in some major cities and urban agglomerations (Hu et al., 2011; Huang et al., 2014). Previous studies showed that the physical and chemical properties as well as biological toxicity changed after the primary particles were converted into secondary particles (Chu et al., 2016; Khalizov et al., 2013). Black Carbon (BC) is one of the main carbonaceous components of primary particles. It is generated from the incomplete combustion of biomass fuels or fossil fuels (Janssen et al., 2011). Studies revealed that BC can induce oxidative stress and inflammatory response in human body, causing respiratory and cardiovascular system damage (Hua et al., 2014; Lin et al., 2011). Fresh BC undergoes aging when it reacts with other pollutants over long-distance transformation and plays a catalytic role in the heterogeneous transformation of many pollutants (such as O 3 , SO 2 and PAHs) and the gas-to-particle conversion process (Xu et al., 2015).These processes not only altered atmospheric com- position, but also changed the physicochemical properties and toxicity of BC, further impacting BC’s climate and health effects. Polycyclic Aromatic Hydrocarbons (PAHs) can react with atmospheric oxidants such as %OH and O 3 to induce heterogeneous or photochemical reac- tions, and then produce oxygenated polycyclic aromatic hydrocarbons (OPAH) such as ketones and quinones, which are more carcinogenic (Xia et al., 2004). OPAH can distribute to the particulate phase more easily as an important component of organic aerosols. The oxidiztion of http://dx.doi.org/10.1016/j.etap.2017.06.012 Received 11 April 2017; Received in revised form 10 June 2017; Accepted 19 June 2017 ⁎ Corresponding author. 1 These authors contributed equally to this work. E-mail address: jiaguangjia@bjmu.edu.cn (G. Jia). Environmental Toxicology and Pharmacology 54 (2017) 21–27 Available online 20 June 2017 1382-6689/ © 2017 Elsevier B.V. All rights reserved. MARK