市售水龙头铅污染的实验研究

Investigation of Lead Pollution of Taps in Market

目的了解市售水龙头对水的铅污染。方法于2006年7—9月采集市售16种水龙头[2种无规共聚聚丙烯(PPR)水龙头,14种金属水龙头,每种各3件],用蒸馏水分别浸泡4、8和12h,用石墨炉原子吸收光谱法测定浸泡水中铅含量。结果PPR水龙头浸泡液中未检出铅。14种金属水龙头中仅1种的浸泡液未检出铅。浸泡液的最高铅浓度为56.54μg/L,中位数为5.79μg/L。黄铜阀芯水龙头浸泡液的铅浓度高于陶瓷芯,差异有统计学意义(P<0.01)。黄铜阀芯水龙头浸泡液铅浓度超过10μg/L的占72.2%(13/18),而陶瓷芯仅为9.5%(2/21),差异有统计学意义(P<0.01)。随浸泡时间延长,黄铜阀芯水龙头浸泡液的铅浓度呈上升趋势(P<0.01),但陶瓷芯水龙头上升不明显(P>0.05)。有注册商标水龙头浸泡液的铅浓度低于无注册商标水龙头,差异有统计学意义(P<0.05)。结论黄铜阀芯水龙头对水的铅污染比较严重,应选择性使用陶瓷芯水龙头,普及无铅水龙头。

Objective To investigate lead pollution of tap in market. Methods 16 taps （2 PPR taps and 14 metal taps）were collected and were sunk in distilled water for 4 hours,8 hours and 12 hours. Lead levels in the distilled waters were determined by atomic absorption spectrometry. Results No lead was detected for PPR taps. Of 14 metal taps,only one tap was not observed lead pollution. The top lead level was 56.54 μg/L,the median was 5.79 μg/L. These brass taps resulted in higher lead pollution than those taps with ceramic preformed core （P〈0.01）. The longer time was,the higher lead levels would be,but statistical significance was not observed for taps with ceramic preformed core（P〉0.05）. 72.2% of the samples with brass preformed core exceeded 10 μg/L and only 9.5% for those taps with ceramic preformed core. These taps with registered trade mark had a slighter lead contamination than those without registered trade mark（P〈0.05）. Conclusion The taps with brass preformed core have worse lead pollution than that with ceramic preformed core. The taps with ceramic preformed core will be a better choice for the prevention of lead contamination.