Kawai Toshio, Ukai Hirohiko, Inoue Osamu, Maejima Yuki, Fukui Yoshinari, Ohashi Fumiko, Okamoto Satoru, Takada Shiro, Sakurai Haruhiko, Ikeda Masayuki
Osaka Occupational Health Service Center, Japan Industrial Safety and Health Association, Nishi-ku, Osaka 550-0001, Japan.
Int Arch Occup Environ Health. 2008 Jan;81(3):253-62. doi: 10.1007/s00420-007-0203-2. Epub 2007 Oct 13.
The purpose of the present study was to compare validity of various biomarkers of occupational exposure to toluene (Tol) at low levels. The focus was placed on the comparison of un-metabolized toluene in urine (Tol-U) and peripheral blood (Tol-B) with hippuric acid in urine (HA-U).
Surveys were conducted in 16 workplaces on the second half of working weeks, with participation of male solvent workers. Urine and peripheral blood samples were collected at the end of the shifts. After exclusion of cases with dense or diluted urine samples, 473 valid sets of samples were obtained for statistical evaluation. Time-weighted average exposure (for about 8-h) were monitored by diffusive sampling for toluene and other four solvents. Blood samples were subjected to the analyses for Tol-B, whereas urine samples were analyzed for HA-U and Tol-U.
The solvent exposures were low, i.e., a grand geometric mean (GM) Tol concentration was 1.6 ppm, and the GM for the SUM in the additiveness equation was 0.12. The correlation analyses of the biomarkers in urine and blood with Tol exposure showed that Tol-U and Tol-B were more closely [correlation coefficients (r) being 0.67 and 0.60, respectively] related than HA-U (r = 0.27). Results of receiver operator characteristic analyses were in agreement with the correlation analysis results.
Taking the non-invasive nature of sampling together, Tol in the end-of-shift spot urine sample appears to be the marker of choice for biological monitoring of occupational exposure to Tol at low levels such as <2 ppm as a geometric mean.
本研究旨在比较低水平职业性甲苯（Tol）暴露的各种生物标志物的有效性。重点是比较尿中未代谢的甲苯（Tol-U）和外周血中的甲苯（Tol-B）与尿中马尿酸（HA-U）。
在16个工作场所的工作周后半段进行调查，参与对象为男性溶剂工人。在轮班结束时采集尿液和外周血样本。排除尿样浓缩或稀释的病例后，获得473套有效样本用于统计评估。通过扩散采样监测甲苯和其他四种溶剂的时间加权平均暴露量（约8小时）。对血样进行Tol-B分析，对尿样进行HA-U和Tol-U分析。
溶剂暴露水平较低，即甲苯的几何均数（GM）浓度为1.6 ppm，相加方程中总和的GM为0.12。尿和血中生物标志物与甲苯暴露的相关性分析表明，Tol-U和Tol-B的相关性更强（相关系数r分别为0.67和0.60），高于HA-U（r = 0.27）。受试者工作特征分析结果与相关性分析结果一致。
综合采样的非侵入性特点，轮班结束时的即时尿样中的甲苯似乎是低水平职业性甲苯暴露（几何均数<2 ppm）生物监测的首选标志物。
