Nilsson R I, Nordlinder R G, Tagesson C, Walles S, Järvholm B G
Department of Internal Medicine, Göteborg University, Sweden.
Am J Ind Med. 1996 Sep;30(3):317-24. doi: 10.1002/(SICI)1097-0274(199609)30:3<317::AID-AJIM10>3.0.CO;2-Z.
To study genotoxic effects of exposure to low levels of benzene, single-strand breaks (SSB) in DNA of leukocytes and urinary levels of the oxidative DNA adduct 8-hydroxydeoxyguanosine (8OHdG) were determined in 33 men occupationally exposed to benzene from gasoline and in 33 controls. The average exposure to benzene over a shift was determined by personal air sampling in the breathing zone. The 8-hr time-weighted average exposure to benzene was 0.13 ppm (mean value, range 0.003-0.6 ppm). Exposed workers had a significant increase of SSB (p = 0.04) over the shift compared with controls. Storage time of the samples seemed to affect the results. An analysis of samples with the same storage time showed a nonsignificant increase among the workers compared with controls. Urinary 8OHdG increased over the shift among the exposed workers but not among the controls. The highest values among the exposed workers were seen in late evening, with a slight decrease the next morning. Multiple linear analysis adjusting for smoking habits showed a significant association between the exposure level of benzene during the shift and the increase of 8OHdG in the urine over the shift among exposed workers (p = 0.02). These findings indicate a genotoxic effect in humans of benzene at relatively low exposure levels, that is, about 0.1 ppm (0.3 mg/m3).
为研究低剂量苯暴露的遗传毒性效应，对33名职业性接触汽油中苯的男性和33名对照者测定了白细胞DNA中的单链断裂（SSB）以及氧化性DNA加合物8-羟基脱氧鸟苷（8OHdG）的尿水平。通过呼吸带的个人空气采样测定一个班次内苯的平均暴露量。8小时时间加权平均苯暴露量为0.13 ppm（平均值，范围0.003 - 0.6 ppm）。与对照组相比，暴露工人在一个班次内的SSB显著增加（p = 0.04）。样本的储存时间似乎会影响结果。对储存时间相同的样本进行分析显示，与对照组相比，工人中的增加不显著。暴露工人在一个班次内尿中8OHdG增加，而对照组未增加。暴露工人中最高值出现在傍晚，次日早晨略有下降。对吸烟习惯进行校正的多元线性分析显示，一个班次内苯的暴露水平与暴露工人在一个班次内尿中8OHdG的增加之间存在显著关联（p = 0.02）。这些发现表明，苯在相对低的暴露水平即约0.1 ppm（0.3 mg/m³）时对人类具有遗传毒性效应。
