This study investigated personal exposure of mail carriers to atmospheric benzene, toluene, ethylbenzene, and xylenes (BTEX) and estimated their carcinogenic and non-carcinogenic risks due to their exposure to these compounds. A total of 36 mail carriers and 24 post office employees as the control group working in Tehran were included in this study. Spot urine samples were also collected before and after shifts. Monte Carlo simulations were used to estimate the distributions of carcinogenic and non-carcinogenic risks from BTEX exposures. Mail carriers were exposed to 10.4 (± 6.2), 35.3 (± 15.5), 5.5 (± 2.3), and 23.1 (± 10.4) μg/m³ as the average (±SD) concentrations of benzene, toluene, ethylbenzene, and xylenes, respectively. The urinary concentrations of these compounds were 124.0 (±61.2), 242.5 (±96.9), 140.7 (±74.2), and 444.3 (±147.0) ng/L, respectively. These values were significantly higher than those observed for control group. For mail carriers, after-shift urinary concentrations of BTEX were statistically higher than before-shifts concentrations. Carcinogenic risks of mail carriers were higher than those for control group with a mean of 5.82×10⁻⁶ exceeding the US EPA limits. Sensitivity analyses showed that concentration had the highest effect on the estimated risks, followed by exposure frequency and exposure time. This study showed that mail carriers are exposed to BTEX at levels that increase their risk to develop cancer. Therefore, programs to reduce the cancer risk among mail carriers should be designed to reduce exposures, possibly by changing shift hours, working days per year, and total years of occupation.

这项研究调查了邮递员对大气中苯，甲苯，乙苯和二甲苯（BTEX）的个人暴露，并估计了由于暴露于这些化合物而导致的致癌和非致癌风险。这项研究包括在德黑兰作为对照组的总共36个邮递员和24个邮局雇员。轮班前后也采集尿液样本。蒙特卡洛模拟用于估计BTEX暴露致癌和非致癌风险的分布。邮件载体暴露于10.4（±6.2），35.3（±15.5），5.5（±2.3）和23.1（±10.4）μg/ m ³分别为苯，甲苯，乙苯和二甲苯的平均（±SD）浓度。这些化合物的尿液浓度分别为124.0（±61.2），242.5（±96.9），140.7（±74.2）和444.3（±147.0）ng / L。这些值显着高于对照组的观察值。对于邮递员，BTEX的班后尿液浓度在统计学上高于班前尿液浓度。邮递员的致癌风险高于对照组，平均为5.82×10 ^-6超过美国EPA限制。敏感性分析表明，浓度对估计的风险影响最大，其次是暴露频率和暴露时间。这项研究表明，邮递员暴露于BTEX的水平会增加其罹患癌症的风险。因此，应设计降低邮递员癌症风险的计划，以减少可能的暴露，可能是通过改变轮班时间，每年的工作日和总工作年限来减少。