Assessing BTEX concentrations emitted by hookah smoke in indoor air of residential buildings: health risk assessment for children.

Hookah smoke is one of the major indoor sources of Volatile Organic Compounds (VOCs), including Benzene, Toluene, Ethylbenzene, and Xylenes (BTEX). The present study aimed to investigate potential exposure to BTEX compounds among primary school children whose parents smoked hookah at home. BTEX concentrations in indoor air were measured in 60 residential buildings of Khesht, southwestern Iran (case = 30 and control = 30). Target compounds were sampled by charcoal tubes, and the samples were then analyzed by GC-FID. Monte Carlo simulation was used to assess the carcinogenic and non-carcinogenic risks of BTX exposure for the children aged 7-13 years. The concentrations of benzene (7.19 ± 3.09 vs. 0.82 ± 0.5 μg/m), toluene (1.62 ± 0.69 vs. 0.3 ± 0.22 μg/m), and xylenes (2.9 ± 1.66 vs. 0.31 ± 0.22 μg/m) were considerably higher in the indoor air of the case houses compared with the control houses (p < 0.05). The Incremental Lifetime Cancer Risk (ILCR) of benzene for non-smoking and smoking houses were estimated 1.8 × 10 and 15 × 10, respectively, exceeding the recommendations of the World Health Organization (WHO) and the Environmental Protection Agency (EPA) (1 × 10). Moreover, Hazard Quotients (HQs) of all BTX compounds were < 1. The indoor benzene concentration was significantly influenced by the floor at which families lived and type of the kitchen. In order to prevent children's exposure to BTX emitted by hookah, banning indoor smoking is the only way to eliminate these compounds in the indoor air.