目標：本研究利用臍帶血中金屬濃度作為環境暴露監測工具，初探國內新生兒臍帶血中各種金屬元素濃度分布常模值。方法：自2004年5月至2005年7月間，收集來自於不同層級醫療院所的1,526對產婦及其新生兒為研究對象。臍帶血樣本由醫護人員在產婦分娩時採集，之後以感應耦合電漿質譜儀進行分析，總共有1,407個臍帶血樣本完成十八種金屬含量分析。結果：鋅、銅、硒等濃度值最高，其中位數分別為2,296 μg/L，519 μg/L，204 μg/L。錳、鉛、汞、砷等濃度次之，中位數分別為47.6 μg/L，13.2 μg/L，9.4 μg/L，3.2 μg/L。鈹、鉑、鉈、釷及鈾等金屬元素濃度在臍帶血中相對較低。臍帶血樣本中只有硒之原始濃度符合常態分布，鋅、砷及汞等元素濃度經對數轉換後，也符合常態分布條件。結論：目前台灣地區臍帶血中鉛濃度已降至與已開發國家相當，汞與鎘濃度在過去二十年間雖有明顯下降，但仍比其他已開發或開發中國家為高。建議國內未來應建立長期性臍帶血金屬濃度監測系統，作為行政決策或研究長期污染暴露變化趨勢之基礎。

Objectives: In this study, a survey of background multi-element exposure levels was conducted to establish exposure norms in Taiwan through the monitoring of levels of metals in umbilical cord blood. Methods: In total, 1,526 pairs of pregnant women and newborns were recruited between May 2004 and July 2005 at different levels of medical facilities. Cord blood samples were collected by nurses after delivery and 1,407 samples were successfully analyzed for 18 metals with inductively coupled plasma mass spectrometry. Results: The highest concentrations were found for zinc, copper, and selenium with medians of 2,296 μg/L, 519 μg/L, and 204 μg/L, respectively. These were followed by concentrations of manganese, lead, mercury, and arsenic with medians of 47.6 μg/L, 13.2 μg/L, 9.4 μg/L, and 3.2 μg/L, respectively. The lowest levels were observed for beryllium, platinum, thallium, thorium, and uranium. Only the original selenium level and the log-transformed zinc, arsenic and mercury levels were normally distributed. Conclusions: Currently, the cord blood lead level in Taiwan is comparable to those in developed countries. However, although significantly decreased in the past two decades, cord blood mercury and cadmium levels in Taiwan are still higher than those of either developing or developed countries. In the future, a longitudinal monitoring system for cord blood metals should be established to serve as the basis for policy decisions or research on the trend of long-term exposure to pollutants.