Saarinen L, Hakkola M, Pekari K, Lappalainen K, Aitio A
Finnish Institute of Occupational Health, Helsinki, Finland.
Int Arch Occup Environ Health. 1998 Mar;71(2):143-7. doi: 10.1007/s004200050262.
Organic oxygenates, namely, methyl tert-butyl ether (MTBE) and methyl tert-amyl ether (MTAE), are added to gasoline to reduce carbon monoxide in exhausts and to enhance the octane number. The aim of this study was to investigate road-tanker drivers' exposure to oxygenate vapors during road-tanker loading and unloading as well as to evaluate the measurements of these ethers and their metabolites in the urine as a means of assessing the uptake of the ethers. A total of 11 drivers in different parts of Finland were trained to monitor their exposure with personal samplers, to report their working conditions, and to collect their whole-day urine samples. Charcoal tubes of the air samples were analyzed for MTBE, MTAE, benzene, toluene, and aliphatic hydrocarbons. For biological monitoring purposes the two main oxygenates, tertiary ethers MTBE and MTAE, as well as their main metabolites, tertiary alcohols tert-butanol (TBA) and tert-amyl alcohol (TAA), were determined in urine specimens. On average the drivers were exposed to vapors for short periods (21 +/- 14 min) three times during a work shift. The mean concentrations of MTBE and MTAE (mean +/- SD) were 8.1 +/- 8.4 and 0.3 +/- 0.4 mg/m3. The total MTBE uptake during the shift was calculated to be an average of 106 +/- 65 mumol. The mean concentrations of MTBE, TBA, MTAE and TAA detected in the first urine after the work shift were 113 +/- 76, 461 +/- 337, 16 +/- 21, and 40 +/- 38 nmol/l, and those found the next morning, 16 h later, were 18 +/- 12, 322 +/- 213, 9 +/- 10, and 20 +/- 27 nmol/l. The good relationship (r = 0.84) found between MTBE exposure and postshift excretion suggests that urinary MTBE can be used for biological monitoring of exposure, but at the present low level of exposure the corresponding metabolite TBA is not equally reliable. The determination of MTAE and its metabolite TAA in urine is sensitive enough to detect the low degree of exposure to MTAE, but in this study the data were too scarce to allow calculation of the correlations due to very low levels of MTAE exposure.
有机含氧化合物，即甲基叔丁基醚（MTBE）和甲基叔戊基醚（MTAE），被添加到汽油中以减少尾气中的一氧化碳并提高辛烷值。本研究的目的是调查公路油罐车司机在装卸过程中对含氧化合物蒸汽的暴露情况，并评估尿液中这些醚及其代谢物的测量结果，以此作为评估醚摄取量的一种方法。芬兰不同地区的11名司机接受了培训，使用个人采样器监测他们的暴露情况，报告他们的工作条件，并收集全天的尿液样本。对空气样本的活性炭管进行分析，检测其中的MTBE、MTAE、苯、甲苯和脂肪烃。出于生物监测目的，在尿液样本中测定了两种主要的含氧化合物，叔醚MTBE和MTAE，以及它们的主要代谢物，叔醇叔丁醇（TBA）和叔戊醇（TAA）。平均而言，司机在一个工作班次中会有三次短时间（21±14分钟）暴露于蒸汽中。MTBE和MTAE的平均浓度（平均值±标准差）分别为8.1±8.4和0.3±0.4毫克/立方米。该班次期间MTBE的总摄取量经计算平均为106±65微摩尔。在工作班次结束后的首次尿液中检测到的MTBE、TBA、MTAE和TAA的平均浓度分别为113±76、461±337、16±21和40±38纳摩尔/升，而在16小时后的第二天早晨检测到的浓度分别为18±12、322±213、9±10和20±27纳摩尔/升。MTBE暴露与班次后排泄之间存在良好的相关性（r = 0.84），这表明尿液中的MTBE可用于暴露的生物监测，但在目前较低的暴露水平下，相应的代谢物TBA并不同样可靠。尿液中MTAE及其代谢物TAA的测定足够灵敏，能够检测到对MTAE的低程度暴露，但在本研究中，由于MTAE暴露水平极低，数据过于稀少，无法计算相关性。
