Zarezadeh Elnaz, Jonidi Jafari Ahmad, Gholami Mitra, Farzadkia Mahdi, Ashouri Ehsan, Shahsavani Abbas, Kermani Majid, Nakhjirgan Pegah
Department of Environmental Health Engineering, School of Public Health, Iran University of Medical Sciences, Tehran, Iran.
Research Center for Environmental Health Technology, Iran University of Medical Sciences, Tehran, Iran.
Heliyon. 2024 May 22;10(11):e31640. doi: 10.1016/j.heliyon.2024.e31640. eCollection 2024 Jun 15.
Substances like asbestos and other air pollutants, such as BTEX (benzene, toluene, ethylbenzene, and xylene), are hazardous compounds due to their adverse effects on human health. This study aims to investigate the levels, seasonal variations, spatial distribution, potential sources, and associated health risks associated with BTEX compounds and asbestos fibers in the ambient air of Tabriz. Air samples were taken at 16 different locations during the 2020-2021 period. Glass containers with charcoal were used for sample collection, and the BTEX content was determined using the GC-FID method. Phase-contrast microscopy (PCM) analysis was conducted with a low-volume peripheral pump for asbestos fiber sampling. The results showed that the average concentration of ∑BTEX was 37.94 and 27.98 μg/m in autumn and spring, respectively. The same parameter was 2.26 and 1.68 f/L for asbestos in the autumn and winter, respectively. The contribution of BTEX to ozone formation potential (OFP) in the research area showed that xylene and toluene were the major contributors to ozone production in different seasons. The risk of exposure to benzene compounds was 24 × 10 in children and 55.9 × 10 in adults, while the risk of exposure to ethylbenzene was 3.78 × 10 in children and 3.25 × 10 in adults. The estimated lifetime cancer risk was found to be the highest for benzene, followed by ethylbenzene. The estimated cancer risk for benzene and ethylbenzene exceeded the threshold values set by EPA, which signals a significant carcinogenic risk due to exposure to these substances in the ambient air of Tabriz. According to the EPA guidelines, the low carcinogenicity risk levels are between 10 and 10. According to the findings for the exposure to asbestos fibers, the maximum values of excess cancer risk (ECR) and estimated lifetime cancer risk (ELCR) were observed in the 16-30 age range across all locations, suggesting increased exposure to asbestos fibers compared to other age groups.
石棉等物质以及其他空气污染物，如BTEX（苯、甲苯、乙苯和二甲苯），因其对人体健康的不利影响而成为有害化合物。本研究旨在调查大不里士市环境空气中BTEX化合物和石棉纤维的含量、季节变化、空间分布、潜在来源以及相关的健康风险。在2020 - 2021年期间，于16个不同地点采集了空气样本。使用装有活性炭的玻璃容器进行样本采集，并采用气相色谱 - 火焰离子化检测法（GC - FID）测定BTEX含量。使用低流量外周泵进行相衬显微镜（PCM）分析以采集石棉纤维样本。结果表明，秋季和春季∑BTEX的平均浓度分别为37.94和27.98μg/m³。秋季和冬季石棉的该参数分别为2.26和1.68 f/L。研究区域内BTEX对臭氧生成潜势（OFP）的贡献表明，在不同季节，二甲苯和甲苯是臭氧产生的主要贡献者。儿童接触苯化合物的风险为24×10⁻⁶，成人接触苯化合物的风险为55.9×10⁻⁶，而儿童接触乙苯的风险为3.78×10⁻⁶，成人接触乙苯的风险为3.25×10⁻⁶。估计终生患癌风险中苯最高，其次是乙苯。苯和乙苯的估计患癌风险超过了美国环境保护局（EPA）设定的阈值，这表明由于在大不里士市环境空气中接触这些物质存在显著的致癌风险。根据EPA指南，低致癌风险水平在10⁻⁶至10⁻⁴之间。根据石棉纤维接触情况的研究结果，在所有地点的16 - 30岁年龄范围内观察到了超额患癌风险（ECR）和估计终生患癌风险（ELCR）的最大值，这表明与其他年龄组相比，该年龄组接触石棉纤维的情况有所增加。
