台北地區小規模住戶及學校自來水含鉛濃度調查及新水龍頭鉛溶出研究

Abstract

鉛管自1980年代開始被世界各國禁止使用於配水系統中。然而，鉛仍時常被用來製造管材元件，從而導致自來水鉛污染及危害人體健康。本研究針對台北地區的20個住戶(包含10戶鉛管換管戶和10戶無鉛管戶)及10所學校進行五次實地自來水採樣以了解自來水含鉛概況，並且購買新黃銅水龍頭及無鉛水龍頭安裝於國立台灣大學一館舍內，以調查3個月左右之鉛溶出狀況。本研究分析住戶及學校自來水總鉛和溶解鉛濃度，並探討鉛濃度與各水質參數的相關性。在新水龍頭實驗中，則檢測分析總鉛、銅、鋅、鐵和溶解鉛、銅、鋅、鐵濃度以探討鉛濃度與銅、鋅、鐵濃度的相關性。此外，本研究使用單粒子感應耦合電漿質譜儀(single particle inductively coupled plasma mass spectrometry, spICP-MS)，檢測及量化鉛、銅、鋅、鐵奈米顆粒的粒徑分佈、粒子數濃度和粒子濃度。實驗結果顯示，在現地住戶及學校採樣分析的研究中，大部分自來水樣品的鉛濃度不高，僅有一個樣品超過台灣飲用水含鉛量標準 (10 μg/L)。鉛濃度與各水質參數則無相關性。在新水龍頭實驗中，其中一個黃銅水龍頭於前兩個禮拜左右釋出高濃度鉛(最高達24.3 μg/L) ，而無鉛水龍頭於實驗期間皆釋出低濃度鉛(<6 μg/L)。 其中一個黃銅水龍頭的鉛奈米顆粒濃度隨時間逐漸下降，而另外兩個黃銅水龍頭的鉛奈米顆粒濃度則大幅波動。總/溶解鉛與總/溶解鋅和銅於黃銅水龍頭中具有相關性，而鉛奈米顆粒濃度於無鉛水龍頭和管道系統中的銅、鋅、鐵奈米顆粒濃度則具有相關性。

Lead pipes were banned from use in distribution system in the 1980s. Nevertheless, lead is frequently utilized as an additive in plumbing components, which can endanger the public health by causing lead contamination in tap water. In this study, lead survey campaign consisting of five sampling events were conducted for 20 residential premises and 10 schools at the Greater Taipei Area. In addition, brand new brass faucets and lead-free faucets were purchased and installed in a building on the National Taiwan University campus to investigate the leaching of lead for around 3 months. Total lead and soluble lead were analyzed in both field research and new faucet study. Various water quality parameters were measured in the field research to study the relationship between lead concentration and each water quality parameter. Total and soluble copper, zinc, iron were analyzed in the new faucet study to investigate their correlations with lead concentration. Furthermore, size distribution, number concentration and mass concentration of lead, copper, zinc, iron nanoparticles were analyzed using single particle inductively coupled plasma mass spectrometry (spICP-MS) in the new faucet research. In the lead survey campaign, most samples had low lead concentrations, with only one sample exceeded the Taiwan drinking water standard (10 μg/L). There were no correlations between lead concentration and various water quality parameters. In the new faucet study, one brass faucet released high level of lead (maximum 24.3 μg/L) initially for about two weeks while lead-free faucet released low level of lead concentration (<6 μg/L) in tap water. The mass concentration of lead nanoparticles reduced gradually over time in one brass faucet but fluctuated greatly in the other two brass faucets. Total/soluble lead were correlated with total/soluble copper and zinc in brass faucet while lead nanoparticle mass concentration was correlated with copper, zinc and iron nanoparticle mass concentrations in new lead-free faucet and the plumbing system.