\\n\\nBackground: Exposure to lead (Pb), arsenic (As), and copper (Cu) can cause serious health problems. We’re talking about brain damage, cancer, or organ issues. So, knowing how much of these metals are in our drinking water, at levels that actually affect people, is super important.\\n\\nObjective: We wanted to figure out the actual amounts of lead, arsenic, and copper in drinking water. We collected samples from homes that were part of the American Healthy Homes Survey II, a national project that checks for lead and other dangers in US homes.\\n\\nMethods: We took drinking water samples from 678 US homes where kids might live. We used a specific method to collect composite samples, which helps us understand real-world exposure. Then, we looked at how metal levels related to the water source and how old the house was.\\n\\nResults: Out of 678 samples, 18 (2.6%) had more than 5 µg of lead per liter. The average was 1.0 µg/L. For arsenic, 1.5% of samples were over 10 µg/L, with an average of 1.7 µg/L. And for copper, 1.5% were over 1,300 µg/L, averaging 125 µg/L. Homes using private wells were more likely to have high metal levels than those on public water. We also saw that lead levels often went hand-in-hand with copper and zinc, suggesting that brass-containing fixtures were a common source of lead.\\n\\nSignificance: This study is the biggest national effort yet to understand the risks of lead, arsenic, and copper exposure in US home drinking water, using a sampling method that focuses on actual exposure.\\n\\nImpact statement: Right now, we don’t have national data on lead, arsenic, and copper levels in US tap water collected using an exposure-based method. This makes it tough to really gauge the public health effects of these metals in our drinking water. The results from our study are a huge step forward. They represent the largest project to date to test for exposure-relevant amounts of lead, arsenic, and copper in US household drinking water, helping us understand metal exposure risks much better.\\n\\n