Calvert G M, Talaska G, Mueller C A, Ammenheuser M M, Au W W, Fajen J M, Fleming L E, Briggle T, Ward E
Division of Surveillance, Hazard, Evaluations and Field Studies, National Institute for Occupational Safety and Health, Centers for Disease Control and Prevention, 4676 Columbia Parkway, R-21, Cincinnati, OH 45226, USA.
Mutat Res. 1998 Sep 11;417(2-3):115-28. doi: 10.1016/s1383-5718(98)00105-3.
To address the genotoxicity of in vivo methyl bromide (CAS 74-83-9) exposure in humans, we collected blood and oropharyngeal cells as part of a cross-sectional morbidity study of methyl bromide-exposed fumigation workers and their referents. Micronuclei were measured in lymphocytes and oropharyngeal cells, and hypoxanthine-guanine phosphoribosyl transferase gene (hprt) mutations were measured in lymphocytes. A total of 32 workers and 28 referents provided specimens. Among current non-smokers, mean hprt variant frequencies (Vfs) were found to be elevated among workers compared to referents (geometric mean: workers=4.49x10(-6), referents=2.96x10-(6); two-sided p=0.22); this difference was more pronounced among workers with 4 h or more of recent methyl bromide exposure compared to referents (geometric mean: workers=6.56x10(-6), referents=2.96x10(-6); two-sided p=0.06). Mean oropharyngeal cell micronuclei were higher among workers compared to referents (mean: workers=2.00, referents=1.31; two-sided p=0.08); the results were similar when workers with 4 h or more of recent methyl bromide exposure were compared to referents (mean: workers=2.07, referents=1.31; two-sided p=0.13). No consistent differences between workers and referents were observed for frequencies of kinetochore-negative lymphocyte micronuclei, or kinetochore-positive lymphocyte micronuclei. The study was limited by a sample size sufficient only for detecting relatively large differences, absence of a reliable method to measure the intensity of workplace methyl bromide exposures, and relatively infrequent methyl bromide exposure (e.g., the median length of exposure to methyl bromide during the 2 weeks preceding the survey was 4 h). In conclusion, our findings provide some evidence that methyl bromide exposure may be associated with genotoxic effects in lymphocytes and oropharyngeal cells. Further study on the genotoxicity of methyl bromide exposure in humans is warranted.
为了研究人体体内接触甲基溴（化学物质登记号74 - 83 - 9）的遗传毒性，我们收集了血液和口咽细胞，作为对接触甲基溴的熏蒸工人及其对照人群进行横断面发病情况研究的一部分。我们检测了淋巴细胞和口咽细胞中的微核，并在淋巴细胞中检测了次黄嘌呤 - 鸟嘌呤磷酸核糖转移酶基因（hprt）突变。共有32名工人和28名对照者提供了样本。在当前不吸烟者中，发现工人的hprt变异频率（Vfs）平均值高于对照者（几何平均值：工人 = 4.49×10⁻⁶，对照者 = 2.96×10⁻⁶；双侧p = 0.22）；与对照者相比，近期接触甲基溴4小时或更长时间的工人中这种差异更为明显（几何平均值：工人 = 6.56×10⁻⁶，对照者 = 2.96×10⁻⁶；双侧p = 0.06）。工人的口咽细胞微核平均数量高于对照者（平均值：工人 = 2.00，对照者 = 1.31；双侧p = 0.08）；将近期接触甲基溴4小时或更长时间的工人与对照者进行比较时，结果相似（平均值：工人 = 2.07，对照者 = 1.31；双侧p = 0.13）。在工人和对照者之间，未观察到着丝粒阴性淋巴细胞微核频率或着丝粒阳性淋巴细胞微核频率的一致差异。该研究的局限性在于样本量仅足以检测相对较大的差异，缺乏测量工作场所甲基溴暴露强度的可靠方法，以及甲基溴暴露相对不频繁（例如，调查前2周内甲基溴暴露的中位时长为4小时）。总之，我们的研究结果提供了一些证据，表明接触甲基溴可能与淋巴细胞和口咽细胞的遗传毒性效应有关。有必要进一步研究人体接触甲基溴的遗传毒性。
