醫學生甲醛暴露與口腔黏膜細胞微核發生頻率之相關性研究

The Relationship Between Micronuclei in Buccal Mucosa and Formaldehyde Exposure in Medical Students

盧志朋(Chih-Peng Lu)

指導教授 ： 陳叡瑜

臺北醫學大學/公共衛生暨營養學院/公共衛生學研究所/碩士(2000年)

摘要

甲醛為一種用途廣泛的物質，在工業及醫學方面上使用相當多，職業性暴露人口不少。由於甲醛活潑的特性，稍高濃度即會造成多數人的眼、口、鼻黏膜刺激及過敏等急性健康效應；慢性健康效應方面，則會造成姊妹染色體交換（SCE）及染色體變異（CA）等現象，甚至有造成癌症的可能。 有文獻指出：口、鼻黏膜細胞微核的發生率是甲醛暴露者極為敏感的生物指標，由於微核的形成是致癌作用的早期階段，其頻率可作為基因毒物暴露之早期生物效應指標。醫學生在上解剖實驗課時有較高濃度的甲醛暴露，由於甲醛具致癌潛力，在此暴露濃度是否會對醫學生們造成不良的健康效應，值得關切。本研究係運用微核發生頻率為生物指標，來評估醫學生甲醛暴露效應。 在22個區域採樣樣本所測得的甲醛濃度介於0.13-4.15ppm，其平均濃度為1.17±1.00ppm；66個個人採樣樣本的甲醛濃度介於0.09-4.87ppm，平均濃度為1.17±1.12ppm。評估43位上解剖課學生之口腔黏膜細胞微核發生頻率之變化，發現學期初之微核發生頻率MNF（micronucleated frequencies）為9.58 ±0.49（MN cells/1000cells），學期中及學期末分別為15.68 ±0.57（MN cells/1000cells）、16.31 ±0.52（MN cells/1000cells）。經Paired t-test統計檢定顯示，經甲醛暴露後，口腔黏膜細胞微核發生頻率會上升（p＜0.01）；而經過一個寒假後，其下一學初之MNF降為10.86 ±0.53（MN cells/1000cells），與學期初之MNF沒有顯著差異。 本研究結果顯示，在較高濃度的甲醛暴露下，微核發生頻率會上升，但排除暴露後，微核發生頻率又會下降至與暴露前相當之值，口腔黏膜細胞微核，似乎可以作為短期甲醛暴露的生物指標。然而，文獻探討指出，微核發生頻率之增加是早期基因毒性效應，則對甲醛長期暴露者，是否能呈現劑量效應關係有待進一步的探討。

關鍵字

甲醛 ； 微核 ； 解剖實驗室

並列摘要

Formaldehyde is being used widely in industry and medicine. There are many people who are exposed to formaldehyde occupationally. Low level of formaldehyde could cause eye, nose, and upper respiratory irritation. If exposed for a long time, it was reported that formaldehyde could induce tumors in rodents and cause a variety of genotoxic effects, gene mutation to chromosome damage. Moreover, it was recognized as a suspected human carcinogen. Increased micronuclei(MN) frequency has been associated with various exposure and genetic condition. Recent studies show that MN is a highly sensitive marker for estimating occupational exposure to formaldehyde. Buccal mucosa cells are more susceptible to formaldehyde damage compared to nasal cells and lymphocytes with respect to MN formation. The medical students who could exposed formaldehyde more than 1 ppm in the anatomy laboratory class has been reported. The purpose of this study is to evaluate the relationship between formaldehyde exposure and MN formation among medical students who take the anatomy laboratory class. The results showed that the mean value of formaldehyde concentration in 22 area samples was 1.17 ±1.00ppm (ranged from 0.13 to 4.15 ppm), and the mean value of 66 personal samples was almost the same (1.17 ±1.12ppm ranging from 0.09 to 4.87 ppm). A total of 43 students who take the anatomy course completed all the buccal mucosa cells tests. The base line mean value of micronuclei frequency (MNF) was 9.58±0.49(MN cells/1000 cells) before formaldehyde exposure. Compare to the base line data, a significant increased MNF was found ( paired t-test, P<0.01) in the middle and the end of the semester, which was 15.68 ±0.57and 16.31± 0.52(MN cells/1000 cells) respectively. However, the MNF returned to the level of base line (10.86±0.53, paired t-test, P>0.05) after one month of winter vacation. Results indicate that MNF of the buccal mucasa cells was reversible and it is a good biomarker for short-term formaldehyde exposure. However, the lack of variation in exposure level and exposure period demands further studies to confirm the reversibility of MNF and its dose-response relationship for long-term formaldehyde exposure.

並列關鍵字

formaldehyde ； micronuclei ； anatomy laboratory

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