電銲金屬燻煙對去氧核醣核酸甲基化影響研究

Effects of Metal Fume Exposure on DNA Methylation

本研究之目的主要是探討造船業男性電銲作業人員暴露於電銲之金屬燻煙對DNA異常甲基化的影響，採橫斷性研究設計，共招募100名受試者，暴露組73名，對照組行政人員27名；於星期一早上以八小時PM_(2.5)個人式採樣，並在星期二早上進行健康檢查，收集尿液以感應耦合電漿質譜儀（ICP-MS）分析其尿中金屬濃度；並採集血液樣本，收集DNA後進行亞硫酸鹽轉化及聚合酶連鎖反應後以Mass detection進行甲基化分析；使用問卷收集個人基本資料、生活習慣和工作史。在多變項線性迴歸分析中，校正年齡、工作組別、吸菸習慣和二手菸暴露後，PM_(2.5)濃度與LINE-1 CpG8+9甲基化百分比呈顯著正相關（β=0.311，95%CI 0.000-0.015，p=0.042），尿中鉻濃度與LINE-1 CpG8+9甲基化百分比呈顯著負相關（β=-0.313，95%CI -0.014-0.000，p=0.049）。本研究結論為PM_(2.5)與CpG8+CpG9高甲基化有關；尿中鉻濃度為LINE-1 CpG8+9低甲基化的危險因子。

This study is mainly to explore the relationship between DNA methylation and exposure to welding metal fumes. A total of 100 participants were recruited. Subjects were requested to wear a personal PM_(2.5) sampler on Monday morning for consecutive 8-hour working duration. Urine and fasting blood samples were collected on the next day morning. A questionnaire was adopted to collect personal information, lifestyle and working conditions. Linear regression revealed PM_(2.5) level was significantly and positively associated with LINE-1 CpG8+9 methylation percentage after adjusting for age, working group, current smoking habit, and secondhand smoke exposure. Urinary chromium concentration was significantly and negatively associated with the percentage of methylation of LINE-1 CpG8+9 after adjusted for age, working group, current smoking habit, and secondhand smoke exposure. Logistic regression indicated that odds ratio of low percentage for methylation of LINE-1 CpG8+9 was 2.337 or 3.144 with urinary chromium or urinary iron concentration after adjusted urinary creatinine, age, working group, current smoking habits and secondhand smoke exposure, respectively. To sum up, urinary chromium is significantly associated with hypomethylation of LINE-1.