A Case Study of Btex Characteristics and Health Effects by Major Point Sources of Pollution During Winter in Iran Publisher Pubmed



Baghani AN¹ ; Sorooshian A^{2, 3} ; Heydari M¹ ; Sheikhi R¹ ; Golbaz S¹ ; Ashournejad Q⁴ ; Kermani M^{5, 6} ; Golkhorshidi F^{5, 6} ; Barkhordari A⁷ ; Jafari AJ^{5, 6} ; Delikhoon M⁸ ; Shahsavani A^{9, 10} Show Affiliations
Source: Environmental Pollution Published:2019

Abstract

This is the first such study investigating BTEX in this understudied, yet largely populated, region in the Middle East with attention geared towards spatial and diurnal trends, health effects of BTEX, and amount of BTEX emissions in gas stations versus CNG stations. © 2019 Elsevier Ltd; This study characterized spatio-temporal variations in the concentration of benzene, toluene, ethylbenzene, and xylene (BTEX) compounds in the vicinity of gas and compressed natural gas (CNG) stations in Tehran, Iran. Health risk assessment (HRA) was computed using Monte Carlo simulations (MCS) for evaluating inhalation lifetime cancer risk (LTCR), the hazard quotient (HQ), and sensitivity analysis (SA) for BTEX exposure in different age groups (birth to <81) and as a function of distance (0–250 m) from the center of the stations. For all monitoring stations, the average values of benzene, toluene, ethylbenzene, and xylene in winter were 466.09 ± 132.25, 873.13 ± 233.51, 493.05 ± 141.22, and 910.57 ± 145.40 μg m−3, respectively. The mean wintertime ratios of T/B for the 12 stations ranged from 1.69 to 2.04. Furthermore, there was no significant relationship between the concentration of BTEX with either the specific month or distance from the center of stations (p > 0.05). Factors promoting BTEX formation in the study region were fuel evaporation and gas/CNG station emissions. The LTCRs for the target compounds in the winter for different age groups and distances from the center of stations was limited to 2.11 × 10−4 to 1.82 × 10−3 and 2.30 × 10−4 to 2.01 × 10−3, respectively, which exceeded proposed values by U.S. EPA. Moreover, the HQs for BTEX for three age groups and distances were limited to between 2.89 × 10−5 and 9.33 × 10−2, which were lower than the acceptable limit (HQs < 1). The results of this work are applicable to similar areas that are heavily populated with vehicular traffic. This study motivates a closer look at mitigation strategies to limit the health effects of carcinogenic emissions such as benzene and ethylbenzene from gas/CNG stations. © 2019 Elsevier Ltd