2024 Yes Influence of point-of-use filters and stagnation on water quality at a preschool and under laboratory conditions https://www-sciencedirect-com.ezproxy.lib.utexas.edu/science/article/pii/S0043135421012288?via%3Dihub Clark, Gemma G. North America Observational Exposure Water quality Bacteria Point-of-use filter Drinking water Bacteria Chlorine Lead POU filters at a preschool reduced chlorine but raised Pb after stagnation due to downstream plumbing. Over half of filtered samples exceeded 5 µg/L Pb. A 5-minute flush lowered Pb and bacteria. Filters should be part of a broader plumbing strategy. 2022