Lead is one of few substances known to have a direct impact on health through the drinking water supply. Significant amounts of lead can be infiltrated in tap water as a result of leaching in distribution and plumbing system. This research was conducted to characterize Pb in tap water in the 21 districts of Madrid city over a long period of 12 years (2007–2018) and to assess the children health risks generated by the exposure to lead in the water supply. A total of 2308 first-flush water samples were collected from various types of buildings and analyzed for Pb using electrothermal atomic absorption spectroscopy. The sampling was carried out considering different factors: year, district and type of building. Tap water in most samples (96%) complied with the legislation throughout the study period. More cases of non-compliance were observed in 2014 because the impact of stricter regulations entry in force in December 2013 (10 μg/L). It was also significantly higher in the oldest districts located in the central area of Madrid and in households compared to other types of buildings (p < 0.001). The children health risks were assessed using the monitoring data collected from households. The end points of critical effects considered are within the normal range: margin of exposure (MOE) > 1 and average loss of Intelligent quotient (IQ loss) < 1 in 89.9% of the samples, however, the possibility of an adverse effect for infants and young children could not be excluded for a small percentage of samples exceeding 5 µg/L or 10 µg/L respectively corresponding to old households in the central area. The results point to the need of control of water supply including strategies such as the prioritization of inspections in the buildings of that area and the replacement of old pipes.

铅是已知通过饮用水供应对健康有直接影响的少数物质之一。由于分配和管道系统中的浸出，大量的铅会渗入自来水中。这项研究的目的是在长达12年的时间里（2007-2018年）对马德里市21个地区的自来水中的铅进行表征，并评估铅对儿童的健康危害。从各种类型的建筑物中总共收集了2308个第一冲洗水样品，并使用电热原子吸收光谱法分析了铅的含量。进行抽样时要考虑不同的因素：年份，地区和建筑物类型。在整个研究期间，大多数样品（96％）中的自来水均符合法律规定。2014年观察到更多的违规案例，因为更严格的法规于2013年12月生效（10μg/ L）。与其他类型的建筑物相比，位于马德里市中心最古老的地区和家庭中的比率也要高得多（p  <0.001）。使用从家庭收集的监测数据评估了儿童的健康风险。在89.9％的样本中，所考虑的关键效应的终点在正常范围内：暴露裕度（MOE）> 1，平均智商损失（IQ损失）<1，但是，可能会对婴儿产生不利影响对于中部地区的老户，不能排除少部分分别超过5 µg / L或10 µg / L的样品。结果表明需要控制供水，包括优先考虑对该地区建筑物的检查和更换旧管道的策略。