In-Home Tap Water Consumption Trends Changed Among U.S. Children, but Not Adults, Between 2007 and 2016

Despite evidence that tap water is often safer and cheaper than alternative sources, tap water is avoided when perceived to be unsafe. Therefore, we conducted the first nationally representative U.S. trends analysis of in-home tap water avoidance between 2007 and 2016. We tested whether changes occurred during/after the Flint water crisis, and whether not drinking tap from one's main water source differed by age, race/ethnicity, and socioeconomic status across time. Finally, we tested whether tap water avoidance was associated with higher prevalence of bottled water consumption among children. We used data on 12,915 children and 23,139 adults from the National Health and Nutrition Examination Survey. Significant covariate-adjusted quadratic time trends were found in the prevalence of avoiding tap water with an inflection at 2013–2014 for children, but not adults. Piecewise log-binomial regressions estimated that between 2007 and 2014 each survey cycle was associated with 14% lower prevalence of not drinking tap water (prevalence ratio [PR] 0.86, 95% CI: 0.80–0.93), but in 2014–2016 a 53% (95% CI: 1.12–2.09) higher prevalence was found for children corresponding to the water crisis. Younger children, Hispanic, non-Hispanic black, and those from low socioeconomic status backgrounds had consistently higher probability of avoiding tap water over time. Children who avoided tap water had 92% higher prevalence of drinking bottled water. In 2015–2016, 78% of non-Hispanic black children who avoided tap water drank bottled water on a given day. Avoiding tap water may indicate underlying water insecurity in the United States. Efforts to address tap water distrust have critical health and economic implications.