二甲基乙酰胺职业接触及与尿中甲基乙酰胺的关系

[目的]探讨职业二甲基乙酰胺（DMAC）接触与尿中甲基乙酰胺（NMAC）的相关性。[方法]对3家氨纶生产企业6个工种201名工人进行空气中DMAC暴露浓度监测及工作周末班末尿样采集,同时对20名纺丝工连续一周空气样品和班末尿样的采集;分别用气相色谱测定空气中DMAC和尿中NMAC含量。[结果]氨纶生产过程中组件清洗工、纺丝工接触DMAC水平最高（P〈0.0033）,中位数分别为32.10、22.02mg/m3,其尿中NMAC浓度较其他工种高（P〈0.0033）,中位数分别为30.09、22.72mg/gCr;工作周末班末尿NMAC含量与空气中DMAC浓度呈直线相关,直线方程为log（U-NMAC）=0.685＋0.455×log（A-DMAC）（r=0.698,P=0.001）;长期DMAC接触者,接触2d后尿中NMAC呈较高水平（P〈0.0033）;个体DMAC接触代谢转化为NMAC的相对内暴露指数（RIE）与DMAC接触浓度呈负相关（rs=-0.781,P=0.001）。[结论]工作周末班末尿NMAC含量与空气中DMAC浓度呈良好对数线性关系。

Correlation between Urinary N-methylacetamide and Occupational Exposure to N, N-dimethylacetamide

[ Objective ] To examine the correlation between occupational N, N-dimethylacetamide （DMAC） exposures and urinary N-methylacetamide （NMAC）. [ Methods ] A total of 201 workers of 6 work types exposed to DMAC in 3 spandex factories were recruited. Air samples were collected from each work type site, post-shift urine samples at the end of workweek were collected from all studied workers and also from 20 spinning workers at each end of workday for 5 consecutive days. NMAC in urine and DMAC in air were determined by gas chromatography. [ Results ] The time-weighted average （TW.A） air levels of DMAC were highest in module washing and spinning sites （P 〈 0.003 3＂）, medians being 32.10 and 22.02 mg/m3 respectively. The urinary NMAC concentrations in module washing workers and spinning workers were significantly higher than workers of other Work types, medians being 30.09 and 22.72mg/gCr respectively. A linear Correlation was found between the TWA air levels of DMAC and the creatinine- adjusted NMAC levels in urine collected by the end of workweek （r=0.698, P = 0.001）. The linear equation was log（U-NMAC）= 0.685＋0.455 × log（A-DMAC）. After 2 consecutive days of exposure, the urinary NMAC was at a higher level in chronically exposed workers （P〈0.003 3）. A negative linear correlation was found between the DMAC levels in air and the relative internal exposure （RIE） （r,=-0.781, P = 0.001）. [ Conclusion ] Air DMAC contents are significantly correlated with urinary NMAC concentrations after logarithmic transformation.