台灣大學校園內一老舊建築物自來水含鉛濃度調查

Abstract

世界各國在1980年代開始禁止使用鉛管於自來水管網當中。然而，現今許多國家包含臺灣在內，仍然有許多鉛管存在於老舊建築物的配水系統，此外，現今所謂之無鉛管材其含鉛量並不為零。近期美國對於自來水鉛污染的問題進行大範圍的採樣調查，發現自來水鉛污染的問題普遍存在，使得公共用水的安全問題重新受到重視。本研究為調查臺灣大學校園內一已知有鉛管之老舊建築物—二號館之自來水總鉛與溶解態鉛的濃度，並探討自來水中鉛濃度與各項水質參數之關係，以及使用不同採樣方法對於所測得鉛濃度的差異。最後發現在七個採樣點中，於四個已知含有鉛管存在的採樣點測到超過臺灣法規標準10 µg/L之平均總鉛濃度，不同採樣方法包括第一升採樣、序列採樣、隨機時間採樣和放流採樣，所採集到的鉛濃度也有顯著的不同。此外，各項水質參數與鉛濃度之間無發現明顯之相關性。

Lead pipes have been banned in drinking water system in most countries in the 1980s. However, lead pipes still exist in old plumbing system. Furthermore, lead is commonly used as an additive in the manufacturing of various plumbing materials. The survey of lead contamination in tap water conducted in the US showed that lead contamination could be a widespread problem. In this study, a sampling campaign was conducted for 7 faucets in an old building (Building No.2) on the National Taiwan University campus, with a total of 9 sampling events. Total lead and soluble lead were measured along with other water quality parameters in this sampling campaign. Lead concentrations in samples collected by different sampling methods were compared. In 4 out of the 7 sampling sites where the lead pipes still exist, average total lead concentration greater than 10 µg/L were observed. Samples collected by four different sampling methods, namely first draw sampling, sequential sampling, random daytime sampling and flushing sampling showed variable lead levels in tap water. There were no obvious correlations between lead concentration and water quality parameters.