學童的致癌性金屬暴露對於氧化DNA傷害增加的貢獻
許銘麟、王尊彥、郭崇義、張璧伊、吳宗勳、黃帥、林建佑、翁瑞宏
中山醫學大學健康管理學院公共衛生學系
摘要
目的：部分職業流行病學的研究已經指出，砷 (Arsenic (As))、鉻 (chromium (Cr))、鎳 (nickel (Ni)) 等重金屬與人類肺癌間具有相關；然而砷、鉻、鎳等暴露對於兒童健康影響卻是不明確的。在本研究中，我們執行一項斷代研究來探討學童同時暴露於砷、鉻、鎳的濃度和DNA氧化傷害程度之間的可能相關。
方法：研究對象是由142名非抽菸的國小五級學生 (年齡 10-12歲)。流行病學的資料是經由面對面的問卷訪視所收集；尿液樣本的砷、鉻、鎳金屬濃度是利用原子吸收光譜儀 (atomic absorption spectrometry (AAS)) 來測定。而DNA氧化傷害指標，尿液8-hydroxy-2’-deoxyguanosine (8-OHdG)濃度則是使用酵素連結免疫吸附分析試劑 (enzyme-linkedimmunosorbent assay [ELISA]) 來分析。
結果：Median of urinary 8-OHdG level for our study subjects was 11.7 ng/mg creatinine (range, 0.4-59.7). Parents with smoking habits had higher urinary 8-OHdG than those who did not (12.8 vs. 10.6 ng/mg creatinine, P = 0.07). Multiple linear regression analysis also showed that children with higher urinary chromium had an increased urinary 8-OHdG than those with lower urinary chromium (P = 0.03, explained variance 29.4%). Similarly, subjects with higher urinary arsenic had an increased urinary 8-OHdG than those with lower urinary arsenic (P = 0.17, explained variance 22.2%), but there was no obvious relationship between the levels of urinary nickel and 8-OHdG (P = 0.71, explained variance 0.9%) was found. Furthermore, schoolchildren with both of high urinary arsenic and chromium levels had highest 8-OHdG expression (16.1 ± 1.3(SE)) in urine, followed by those with lower arsenic/ higher chromium (14.1 ± 1.6), higher arsenic/ lower chromium (12.9 ± 1.6), and lower arsenic/ lower chromium (11.2 ± 1.3), the trend is prominent (P <0.001).
結論：我們得到的結論是環境中致癌性金屬的暴露包括鉻和砷，可能對孩童在DNA氧化損害上扮演重要的角色。
關鍵字：砷，鉻，鎳，8-hydroxy-2’-deoxyguanosine。