Association between BTEX (benzene, toluene, ethylbenzene and xylene) concentration in ambient air with hematological and spirometric indices: a population-based study

Abstract The study aimed to evaluated the relationship between BTEX (benzene, toluene, ethyl benzene and xylene) concentrations in the ambient air with human biomarkers in Assaluyeh city, Iran. According to the results, the average benzene concentration in the high pollution city was measured at 30.05 µg/m3, which is higher than the value recommended (0.03 mg/m3) by the U.S. Environmental Protection Agency (U.S. EPA). The mean spirometric parameters of the resident population in two high and low pollution areas were forced vital capacity (FVC) (high = 4.52; low = 4.78 L), forced expiratory volume in 1 second (FEV1) (high = 3.52; low = 3.88 L), FEV1/FVC (high = 77.9; low = 82.08%), peak expiratory flow (PEF) (high = 9.76; low = 27.85 L/min), and forced inspiratory flow 25–75% (FEF25-75) (high = 3.17; low = 3.95 L/s). Besides, no statistically significant difference was observed between the two groups by comparison of blood tests and the mean concentration of BTEX. BTEX concentration was measured at zero in low pollution areas due to lack of traffic and industries, but it was higher than the respiratory air standard and in the high-pollution area due to the being close to gas and petrochemical stations and industries in the surrounding. As a result, prolonged exposure to higher concentrations of BTEX increases the risks of respiratory dysfunction.