Benzene, toluene, ethylbenzene and xylene concentrations in atmospheric ambient air of gasoline and CNG refueling stations Sadegh Hazrati 1 & Roohollah Rostami 2 & Mehdi Fazlzadeh 1 & Farhad Pourfarzi 3 Received: 4 February 2015 /Accepted: 8 May 2015 # Springer Science+Business Media Dordrecht 2015 Abstract This study aimed to assess workers’ exposure to ben- zene, toluene, ethylbenzene, and xylene (BTEX) compounds in refueling stations of Ardabil city (Iran). Twenty-four refueling stations including 15 petrol and 9 compressed natural gas (CNG) stations from different regions were selected and moni- tored for ambient BTEX concentrations. Air samples were taken based on NIOSH Manual of Analytical Method no 1501. Target compounds were extracted using CS 2 and analyzed by GC equipped with FID. Average concentrations of benzene, toluene, ethylbenzene, and xylene were obtained 2.01, 1.80, 2.72, and 1.65 mg/m 3 , respectively. Benzene concentrations exceeded the occupational exposure limit set by the Iran Ministry of Health and Medical Education. Its concentrations were significantly higher in commercial areas (2.72 mg/m 3 ) compared to suburban areas (1.89 mg/m 3 ). BTEX concentrations in gasoline stations were slightly, but not significantly, higher than those in CNG stations. Long-term exposure cancer risk of 1884×10 -6 ±390× 10 -6 and hazard index of 22.83±3.66 were estimated for benzene and BTEX compounds, respectively. The results declare the ne- cessity for controlling BTEX emission (mainly benzene) and monitoring employee’ s exposure in refueling stations. Keywords Volatile organic compounds . Air pollution . Refueling station Introduction Development of industries in recent decades has led to serious environmental problems including emission of volatile organ- ic compounds (VOCs) into the urban atmosphere. Benzene, toluene, ethylbenzene, and xylene, known as BTEX, are en- vironmentally important VOCs and emitted into the atmo- sphere from both artificial and natural sources (Caselli et al. 2010; Davil et al. 2013; Fazlzadeh Davil et al. 2012; Liu et al. 2009; Sturaro et al. 2010; Tiwari et al. 2010). These com- pounds are used as raw materials or solvents in various indus- tries and released into the environment through evaporation, leaking from underground fuel tanks as a result of poor main- tenance, vehicle exhaust emissions, combustion of fossil fuels, and evaporative emissions from refueling vehicles, and there- fore, traffic-related sources are considered as the most impor- tant sources for indoor and outdoor ambient air pollution (Bailey and Eggleston 1993; Bauri et al. 2015; Caselli et al. 2010; Esteve-Turrillas et al. 2007; Rad et al. 2014; Singh et al. 1992; Truc and Kim Oanh 2007). Sources for BTEX in indoor environments include infiltration of outdoor air pollution, smoking, paints, adhesives, and other VOC-emitting materials utilized in building interiors (Hazrati et al. 2015; Singh et al. 1992; WHO 2000). BTEX compounds are known as a signif- icant cause of cancer in humans and may develop neurological disorders and symptoms such as weakness, loss of appetite, fatigue, confusion, and the nausea (Hoskins 2011). Benzene is the most toxic compound within the BTEX, and long-term exposure to its low concentrations may increase the incidence of leukemia and aplastic anemia in humans (Baker et al. 1985; Mehlman 1990; Niri et al. 2009; Wong 1995). The * Farhad Pourfarzi f.pourfarzi@arums.ac.ir Sadegh Hazrati S.hazrati@arums.ac.ir 1 Department of Environmental Health Engineering, School of Public Health, Ardabil University of Medical Sciences, Ardabil, Iran 2 Department of Environmental Health Engineering, School of Public Health, Semnan University of Medical Sciences, Semnan, Iran 3 Department of Community Medicine, School of Medicine, Ardabil University of Medical Sciences, Ardabil, Iran Air Qual Atmos Health DOI 10.1007/s11869-015-0349-0