Gobba F, Rosa P, Ghittori S, Imbriani M, Ferrari G, Cavalleri A
Dipartimento di Scienze Biomediche, Università di Modena.
Med Lav. 1997 Jan-Feb;88(1):24-36.
Occupational exposure to perchloroethylene (PCE) was studied in a total of 106 workers in 78 dry cleaning shops in the province of Pavia, Northern, Italy. Environmental monitoring was performed by personal passive sampling. The median time weighted average (TWA) level of PCE was 57 mg/m3, i.e., about 30% of the current Threshold Limit Value (TLV) proposed by the American Conference of Governmental Industrial Hygienists (ACGIH). However, in 12 workers exposure exceeded this limit. Biological monitoring was performed via measurement of urinary trichloroacetic acid (TCA), i.e. the exposure index currently used in Italy, and urinary excretion of unmodified perchloroethylene (PCE-U) in samples collected at the end of the half-shift. Median levels of TCA and PCE were 1.03 mg/l and 17.7 micrograms/l respectively. The correlation coefficient between environmental TWA concentrations of perchloroethylene and PCE-U was 0.755 (0.809 after logarithmic transformation), compared to 0.660 for TCA values. The subjects were then classified as "low exposed" and "heavily exposed" according to whether personal exposure was lower or higher than 57 mg/m3, the median TWA value of the whole group. PCE-U levels were significantly correlated to exposure in both subgroups whereas TCA was correlated only in the "heavily exposed subjects", but not in those with lower exposure. The results of the study show that in the majority of dry cleaning shops exposure to PCE was well below the current occupational limits. Nevertheless surveillance of dry cleaners is recommended as nearly 10% of the workers exceeded the environmental and biological limits. Urinary excretion of unmodified PCE appears to be a very reliable indicator for biological monitoring of PCE exposure in dry cleaning and is also significantly correlated to exposure at low levels. The estimated biological equivalent exposure level (BEEL) for PCE-U, corresponding to the current TLV-TWA proposed by the ACGIH, is 55 micrograms/l. Urinary TCA seems to be less suitable for assessment of individual exposure to perchloroethylene in dry cleaners as it is poorly representative of exposure to low levels of the solvent, which is a very common occurrence in this occupational group nowadays.
对意大利北部帕维亚省78家干洗店的106名工人进行了全氯乙烯（PCE）职业暴露研究。通过个人被动采样进行环境监测。PCE的时间加权平均（TWA）中位数水平为57毫克/立方米，即约为美国政府工业卫生学家会议（ACGIH）提出的当前阈限值（TLV）的30%。然而，有12名工人的暴露超过了这一限值。通过测量尿中三氯乙酸（TCA）（即意大利目前使用的暴露指数）以及在半班次结束时采集的样本中未代谢全氯乙烯（PCE-U）的尿排泄量进行生物监测。TCA和PCE-U的中位数水平分别为1.03毫克/升和17.7微克/升。全氯乙烯环境TWA浓度与PCE-U之间的相关系数为0.755（对数转换后为0.809），而TCA值的相关系数为0.660。然后根据个人暴露量低于还是高于57毫克/立方米（即整个组的TWA中位数）将受试者分为“低暴露”和“高暴露”组。PCE-U水平在两个亚组中均与暴露显著相关，而TCA仅在“高暴露受试者”中与暴露相关，在低暴露者中则不然。研究结果表明，在大多数干洗店中，PCE暴露远低于当前职业限值。然而，鉴于近10%的工人超过了环境和生物限值，建议对干洗工进行监测。未代谢PCE的尿排泄似乎是干洗中PCE暴露生物监测的一个非常可靠的指标，并且在低水平暴露时也与暴露显著相关。对应于ACGIH提出的当前TLV-TWA，PCE-U的估计生物等效暴露水平（BEEL）为55微克/升。尿TCA似乎不太适合评估干洗工个体对全氯乙烯的暴露，因为它不能很好地代表对低水平溶剂的暴露，而这在当今这个职业群体中非常普遍。
