以空氣、皮膚、尿液及血液採樣測定評估泥水業勞工六價鉻暴露

Assessment of Hexavalent Chromium Exposure for Cement Workers by Air, Skin, Urine and Blood Sampling

沈書弘(Shu-Hung Shen)

指導教授 ： 吳俊德

共同指導教授 ： 許憲呈

長榮大學/健康科學學院/職業安全與衛生研究所/碩士(2007年)

https://doi.org/10.6833/CJCU.2007.00094

摘要

為了對泥水作業勞工六價鉻暴露作準確的評估，本研究選取台南縣市53位泥水業勞工進行空氣及皮膚樣本採集，估計勞工吸入及皮膚接觸水泥的六價鉻暴露總量。在暴露測定進行時，以問卷調查勞工工作史及工作時皮膚接觸水泥的頻率，並收集這些勞工尿液及血液檢體進行生物偵測，分析其真正進入人體的總量。採集的空氣與皮膚樣本以紫外可見光分光譜儀(Ultra Violet-Visible Spectroscopy, UV-Vis)進行六價鉻濃度分析，尿液與血液樣本則由原子吸收光譜儀(Atomic Absorption Spectrometer, AA)進行總鉻濃度分析。分析結果顯示，勞工空氣暴露遠低於Occupational Safety and Health Administration (OSHA)制定的Permissible Exposure Limits(PELs)對空氣中六價鉻的八小時暴露容許濃度值5 ?慊/m3，但卻有47%的勞工工作後尿中總鉻濃度大於American Conference of Governmental Industrial Hygienists(ACGIH)所制定的尿中鉻Biological Exposure Index(BEI)值25 μg/L，根據此結果推論皮膚途徑是泥水業勞工六價鉻暴露的主要來源。執行勞工工作後尿中總鉻濃度與一些暴露影響因子的多變量線性迴歸分析後，發現有無嚼食檳榔習慣與工作前尿中總鉻濃度此兩因子，在估計工作後尿中總鉻濃度達統計上顯著意義(R2= 0.3041)。血液分析方面，大部份勞工血中總鉻濃度都非常低，接近一般大眾血中總鉻濃度背景值。而無論是血漿或紅血球樣本，總鉻濃度大都低於偵測下限，但尿中總鉻濃度大於BEI值的比例卻是高的，表示泥水業勞工有一定量的六價鉻暴露，但沒有大於血漿中對六價鉻約2 ppm的還原能力，所以當勞工吸收六價鉻進入到血液時，會先被血漿還原後經由尿液排除，無法進ㄧ步進入紅血球中累積。建議防範泥水業勞工六價鉻暴露，應該從阻絕接觸和減少吸收著手，可行的方法除考慮在水泥中添加硫酸亞鐵等，使六價鉻在水泥中先還原成三價鉻外，或可在勞工皮膚上塗抹含還原能力的護手霜，讓六價鉻還原成三價鉻，減少六價鉻皮膚吸收量，進而降低勞工六價鉻暴露。

關鍵字

水泥 ； 六價鉻 ； 尿液樣本 ； 血液樣本

並列摘要

In this study, fifty three cement workers were recruited from Tainan City and County. Both air and skin sampling were taken to accurately assess the total exposure of Cr6+ from inhalation and dermal contact routes for these cement workers. During the exposure sampling time, a questionnaire was used to investigate the work history and the frequency of dermal contact to cement in a regular work day for each worker. In addition, both urine and blood samples were collected from the workers to estimate the total doses of Cr6+ in their bodies. The concentrations of Cr6+ in the air and skin samples were determined by Ultra Violet-Visible Spectroscopy (UV-Vis). The concentrations of total chromium in the urine and blood samples were measured by Atomic Absorption Spectrometer (AA). The results showed that the measured Cr6+ concentrations in air were far less than the permissible exposure limit of 5 ?慊/m3 in an 8-hour work shift established by Occupational Safety and Health Administration (OSHA). However, the concentrations of total chromium in the end of shift urine samples were 47% greater than 25 μg/L, the Biological Exposure Index (BEI) recommended by American Conference of Governmental Industrial Hygienists(ACGIH). It was concluded that dermal contact was the main route of Cr6+ exposure for cement workers. The relationship between the concentrations of total chromium in the post-shift urine samples and some exposure determinants was explored by conducting a multiple linear regression analysis. It was found that betel nut chewing and the concentrations of total chromium in the pre-shift urine samples were significantly important (R2= 0.3041) in estimating the concentrations of total chromium in the post-shift urine samples. Regarding the analysis of blood samples, the concentrations of total chromium of most workers were very low which was close to the background level of total chromium of general population. No matter the concentrations of total chromium in the samples of blood plasma and red blood cells were lower than the detection limit of total chromium, but the proportion of the concentrations of total chromium in urine samples greater than the BEI value was high. This indicated that the cement workers had certain amount of Cr6+ exposure. However, this amount was not higher than the reduction capacity, 2 ppm, of Cr6+ in blood plasma. When the Cr6+ was absorbed through the skin into the blood, most of the Cr6+ was reduced into Cr3+ which could not cumulate in red blood cells and was excreted by urine. It was suggested that the the protection of cement workers from Cr6+ exposure should focus on the cut-off of dermal absorption of Cr6+. The addition of ferrous sulfate to cement is an appropriate approach to decreasing the dermal exposure to Cr6+ for cement workers. Other alternative of applying cream with some substances which can reduce Cr6+ to Cr3+ and decrease the skin absorption of Cr6+ can also be considered.

並列關鍵字

cement ； hexavalent chromium ； urine samples ； bloold samples

參考文獻

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