Investigations show lead in tap water causes brain damage

According to the U.S. Environmental Protection Agency (EPA) public water cannot exceed .015 mg/liter in more than 10% of tap water samples.  The EPA also claims lead in tap water can cause mental deficits in learning and attention span in children. (1)

The U.S. Center for Disease Control (CDC) states 10 micrograms (ug) per deciliter (dl) is an elevated lead level within blood. (2) In a  1998 sample of 19 states, the CDC found that 7.6 percent of children tested had elevated blood lead levels (BLL). In Ohio, some counties had BLLs in 27.3 percent of tested children.(2)
The affects of lead poisoning can be gradual as lead builds up and is stored in the body's kidneys. A wide range of lead related symptoms, temporary or longer term brain damage is reported by the U.S. National Institutes of Health (NIH).(3) These potential affects of lead are lowered IQ, difficulty concentrating, learning dysfunction, seizures and coma.

Mary Beth St. Clair and Sandra A. Zaslow of the North Carolina Cooperative Extension Service have claimed in a study of water quality and waste management that lead free water is an unenforceable goal. This is in part due to the lack of maximum lead level allowed in tap water by the EPA.(4)

In a 2004 Washington Post investigation, it was discovered multiple cities throughout the United States had tampered with municipal water lead level results. This was later confirmed by a congressional report on the CDC's use of bad data to assess D.C. water contamination levels according to Jessica Gresko of the Associated Press.(8) Among the highest polluted water supplies was that of Washington D.C., and it is believed that both the EPA and city water suppliers may have been avoiding enforcement and costly repairs to the water systems.(5)

In an article published by Sciencedaily.com, blood lead levels below the EPA action level are stated to have negative affects of brain functioning. Moreover, the article references a study published in the New England Journal of Medicine which claims there is evidence that shows lead in levels below 10mcg/dl have adverse affect on children's brains.(6) This is further confirmed by a Medical Medscape Medical News report citing evidence from tests using Magnetic  Resonance Imaging (MRI)(7)

So how much lead is in municipal drinking water supplies nationwide? This question may be harder to answer if similar practices to that reported by the Washington Post continue to occur. Since only 'action' rather than elimination of lead is required by the EPA when water lead levels reach a certain amount, there may indeed be no immediate way to reduce lead levels in municipal water supplies. In such cases,  at home water lead testing kits can be obtained for between $10 and $40 and steps can be taken to reduce lead exposure. These steps involve removing lead from household sources of lead be they plumbing fixtures, paint or water.