轿车内苯系物的健康风险评价

Health Risk Assessment of Benzene Homologues in Sedans Cabins

为分析车内苯系物污染对不同性别驾乘人员的致癌风险和非致癌风险,对65辆轿车内空气中ρ(苯)、ρ(甲苯)、ρ(乙苯)和ρ(二甲苯)进行评价;提出车内苯的基本致癌风险浓度与危险致癌风险浓度概念及其计算公式,并与国内外相关标准中苯系物浓度标准限值进行对比分析.结果表明:65辆轿车内空气中苯系物Hfz(综合非致癌指数)的最大值为0.44,低于US EPA(美国国家环境保护局)规定的非致癌风险基本值(1),对乘客与司机均不存在非致癌风险;但苯对司机Hza(致癌指数)的平均值为129.3×10-6,致癌风险较高;苯对男性乘客、女性乘客、男性司机与女性司机的Cwx(危险致癌风险浓度)分别为450.0、470.0、67.5和70.4μg/m3.GB/T 27630—2011《乘用车内空气质量评价指南》中苯浓度标准限值对司机Hza的平均值为1.59×10-4,大于US EPA规定的苯致癌风险危险值(1×10-4),构成致癌危害;苯系物浓度标准限值对司机Hfz的平均值为1.15,构成非致癌危害.轿车内空气中ρ(苯)、ρ(甲苯)、ρ(乙苯)和ρ(二甲苯)的合理限值分别为0.068、1.000、1.350和1.350 mg/m3.

In order to analyze the carcinogenic and non-carcinogenic health risks of in-car airborne benzene homologues to different receptors such as male passengers, female passengers, male drivers and female drivers, mass concentrations of airborne benzene, toluene, ethylbenzene and xylcnes in the cabins of 65 sedans were assessed. Meanwhile, the concepts and calculating formulas based on mass concentrations of basic cancer risk and dangerous cancer risk of in-car benzene homologues were established. Additionally, the limit levels of benzene homologues in different national and international standards were discussed. The results indicated that in the cabins of 65 vehicles, airborne benzene homologues did not result into non-carcinogenic health risks to drivers and passengers, because the maximum of complex non-cancer index （Hfx） of benzene homologues, 0. 44, is less than the benchmark value （1） by US EPA. However, the average value of cancer index （H） for in-car benzene to drivers, 129.3 ~ 10 ^-6, showed its high cancer risk to drivers in vehicles. Mass concentration values of dangerous cancer risk （ Cwx ） for airborne benzene in cars were 450.0μg/m^3 for male passengers, 470.0 μg/m^3 for female passengers, 67.5 μg/m^3 for male drivers and 70.4μg/m^3 for female drivers, respectively. Furthermore, in China＇s national standard GB/T 27630-2011 Guideline for Air Quality Assessment of Passenger Car, the limit level of benzene results in high carcinogenic health risks to drivers because the average value of Hz~ for benzene to drivers, 1.59 x 10-4, is over than the dangerous value of cancer risk （ 1 x 10^ -4 ） by US EPA. The control concentrations of benzene homologues can result in non-carcinogenic health risks to drivers, because the average value of Hf, for benzene homologues to drivers is 1.15. Finally, the reasonable limit values of airborne benzene, toluene, ethylbenzene and xylenes in sedans cabins are O. 068, 1. 000, 1. 350 and 1. 350 mg/m^3 , respectively.