甲苯接触者呼出气中甲苯动力学研究

对１４名职业性接触者及１８名志原受试者接触甲苯进行研究。班中呼出气中甲苯浓度波动很大。班后甲苯浓度的下降趋势符合两室动力学模型，其中快相半减期为４～５分钟，慢相半减期为２～２．５小时。引入统计矩分析与传统的室模型进行比较。因其计算方便且结果易于解释，矩分析法在动力学研究中具有潜在的意义。甲苯接触者体内平均滞留时间为１６２－２２５分钟，直观地反映出甲苯在体内的排泄。为了建立特定接触浓度的动力学方程式，我们用直线回归法估计Ｙ轴截距（Ａ、Ｂ值）。甲苯空气浓度与Ａ、Ｂ值密切相关（ｒ＝０．４３～０．９２，Ｐ＜０．０５）。从动力学方程中，推算出接触空气甲苯浓度１００ｍｇ／ｍ３（ＴＷＡ－８ｈ），脱离接触０、３０和１８０分钟以及次日晨，呼出气中甲苯职业生物接触限值分别为７０、２０、１０及０．３６ｍｇ／ｍ３。

STUDY OF TOLUENE TOXICOKINETICS IN EXHALE AIR

Workers and 18 volunteers exposed to toluene were studied. Toluene concentrations in the exhale air during the exposure varied apparently. The declining of toluene concentrations in exhale air samples after the end of wornkshift fitted a two-compartment kinetics model consisting of fast phase with half time of 4-5 minutes and slow phase 2-2.5 hours.The statistics momental analysis method was applied to compare with the traditional compartment model. with simple calculation procedure and results easy to explain,statistics momental analysis method has potential toxicological significance in kinetics study. The mean residual times(MRT) of toluene in exposed workers were 162-225 minutes that directly reflected the excretion of toluene of human body. To establish kinetics equations of particular concenttration, linear regressional method was used to estimate intercept of Yaxis(A,B values). The TWA air concentrations were significantly correlated with the A,B values(r=0.043-0.92,p<0.05). From kinetics equations it is suggested that the occupational exposure biological limit values (OBELV) of exhale air concentration for toluene exposure to 100mg/m3(TWA-8h) be 70, 20, 10 and 0.36mg/m3 in the samples taken from 0,30 and 180 minutes since the cessation of exposure and the morning after the workshift respectively.