Lead released into the environment makes its way into the air, soils, and water and can remain in the environment as dust, indefinitely. the epa and the centers for disease control and prevention (cdc) agree that there is no known safe level of lead in a child's blood. lead is harmful to health of all age groups, but especially children. the u. s. has banned leaded gas and leaded paints, yet this toxin is still found in our drinking water. what is the main cause of lead inner drinking water?