The Safe Drinking Water Act requires EPA to determine the level of contaminants in drinking water at which no adverse health effects are likely to occur. These are called maximum contaminant level goals (MCLGs). The maximum contaminant level goal for lead in drinking water is zero because lead is a toxic metal that can be harmful to human health even at low exposure levels.
Young children are particularly at risk to lead because a dose of lead that would have little effect on an adult can have a significant effect on a child. In children, low levels of exposure have been linked to damage to the nervous system, learning disabilities, and impaired formation and function of blood cells.
EPA estimates that 20% or more of a person’s total exposure to lead comes from drinking water. Infants who consume mostly mixed formula can receive 40% to 60% of their exposure to lead from drinking water. Below are possible warning signs of lead exposure: