Benzene Monitoring and S-Phenylmercapturic Acid Determination of Workers at Oil Sites in Congo-Brazzaville

The toxicity of benzene is well known, and its leukemia effect has established. It is a natural constituent of crude oil and the diseases related to its exposure are recognized as occupational diseases. Objective: To assess occupational exposure of benzene to workers in an oil and gas production company. Materials and Methods: Firstly, it was a descriptive, cross-sectional study which consisted of benzene atmospheric quantification in a sample individual measurement of a homogeneous exposure group of workers. Secondly, urinary assays of S-phenylmercapturic acid have been performed at the end of the shift in the selected workers. Results: The study has included 79 (47.88%) workers, 17 atmospheric samples were usable and 79 urinary assays at the end of the shift were performed. The average benzene concentration for all sites was 10 times lower than the regulatory average exposure value (1 ppm = 3.2 mg/m3): average: 0.122 pp, median: 0.053 ppm and range: 0.019 - 1.448 ppm. All 79 urinary assays of S-phenylmercapturic acid with a biological exposure index of less than 25 μg/g creatinine: mean: 0.70 μg/g creatinine, median: 0.52 μg/g creatinine and extends: 0.23 to 6.7 μg/g creatinine. Conclusion: Exposure was below to the limit value for benzene in both atmospheric metrology and biometrology. Therefore it is an occupational group with low exposure to benzene. Thus, the medical supervision will be adapted according to the potentially exposing tasks.

高效液相色谱与液质联用测定尿中苯巯基尿酸的方法比较

[目的]通过高效液相色谱（HPLC）与液质联用（LC/MS）检测尿中苯巯基尿酸（SPMA）的方法比对,评价HPLC方法的可行性。[方法]尿样经50%硫酸酸化、氯仿：异丙醇（体积比为5：1）萃取,挥干残渣用甲醇溶解后经十八烷基硅烷（ODS）柱分离,分别采用紫外检测器和质谱检测器检测;对86名职业苯接触者尿样采用两种方法比对分析,以LC/MS分析数据评定HPLC测定结果的有效性。[结果]HPLC方法和LC/MS方法对SPMA的检出限（LOD）分别为40μg/L和10μg/L,SPMA保留时间分别为31 min和7.8 min左右。86份尿样中有13份为假阳性,两方法检测结果的相关系数为0.915,但HPLC检测数据高估LC/MS数据8%-21%。[结论]HPLC法可作为职业苯接触者生物监测的初步筛检方法,LC/MS可准确定量测定尿中SPMA浓度。

苯暴露对小鼠血液系统和DNA氧化损伤的影响

[目的]观察苯吸入染毒对小鼠的周围血象、尿中苯巯基尿酸(SPMA)和8-羟基脱氧鸟苷(8-OHd G)的影响,探讨苯暴露对血液系统和DNA氧化损伤的作用。[方法]将120只昆明种雄性小鼠随机分为4组,每组30只,低、中、高组苯染毒质量浓度分别为375、750和1 500 mg/m3,对照组吸入空气。采用静式吸入染毒法,每天2 h,每周5 d,持续染毒3个月。分别于染毒后1、2、3个月时,每组随机处死10只小鼠,检测周围血象、尿中SPMA和8-OHd G的水平。[结果]白细胞、红细胞、淋巴细胞计数均随着染毒浓度的升高而降低(P<0.05);尿中SPMA及8-OHd G水平随着苯染毒浓度的增加而升高(P<0.05)。高浓度组染毒3个月时尿中8-OHd G水平明显高于1、2个月(P<0.05)。尿中SPMA及8-OHd G与白细胞计数均呈负相关(rSPMA=-0.718,r8-OHd G=-0.971,均P<0.01)。[结论]亚慢性苯暴露可导致小鼠血液系统和DNA氧化损伤。