Lead exposure is especially harmful to children. Children’s low-level lead exposure is related to behavioral and learning problems, low IQ and hyperactivity, slow growth, hearing difficulties, and anemia. These effects are irreversible, which is why it is important to prevent contact. Drinking water is an important source of lead exposure for children. Lead can enter drinking water by corroding lead-containing pipes, taps, and fixtures. These are more common in buildings built before 1986.
A Harvard University study of 12 states that require testing of school drinking water found that 44% of all schools tested had a lead concentration in at least one water sample that was at or above the state’s action level. The lead concentration that initiates the reaction. The level of action varies from state to state but can reach up to 20 parts per billion. EPA’s action level is 15 parts per billion. However, the US Environmental Protection Agency and the Centers for Disease Control agree that there is no safe level of lead exposure.
with information from: https://oklahomawatch.org/2021/07/09/is-there-lead-in-the-water-thousands-of-schools-and-day-cares-havent-found-out/