Q&A | Experts discuss water safety

By Warren King
Seattle Times medical reporter

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Q: Are children who have been in schools with unsafe lead levels in drinking water at risk of health problems?

A: There is no firm answer. Experts say it depends on the amount of exposure and the child's stage of brain development when exposed. The very young are at highest risk. Health experts say there is no question that the schools should take measures to lower the lead levels in the water.

Q: Is drinking water a major source of lead poisoning in children?

A: No. The primary cause is ingestion of lead-based paint, breathing lead-contaminated dust or consuming contaminated soil.

Q: What are the effects of lead poisoning in children?

A: At high enough levels, it can cause learning disabilities, including attention deficit disorder, behavioral problems, hyperactivity and growth and hearing problems.

Q: When are children most vulnerable?

A : The brain develops most rapidly in the first 18 months of life. Generally, the older the child, the lower the chance of brain damage, says Dr. William Robertson, medical director of the state Poison Center and professor emeritus of pediatrics at the University of Washington.

Q: Could high lead levels in school drinking water alone cause problems?

A: Again, that is difficult to answer. Children also may be exposed to lead in home drinking water. If a child drank a liter of water a day for a year and all of it had an average lead content of 20 parts per billion, his or her IQ could drop 3 points in a year, says Dr. Richard Maas, co-director of the University of North Carolina's Environmental Quality Institute, which researches drinking water.
 
Q: Is there evidence that lead-laced drinking water has caused learning problems in children here or nationwide?

A: Robertson says no. In fact, he said, children's average blood lead levels nationally have dropped from 34 micrograms per deciliter of blood in the 1960s to less than 1 today, but the prevalence of attention deficit disorder — one possible result of lead poisoning — has increased.

Q: If parents are worried their children are overexposed to lead, what can they do?

A: A family's physician or clinic can order a blood lead-level test through a medical laboratory. Lead can be detected in the blood for up to six months after exposure.

Q: Should public-health officials conduct blood tests in children?

A: Robertson said systemized testing would determine the real impact on children. However, neither the state Department of Health nor Public Health — Seattle & King County plans to conduct blood tests because the school exposure is not considered a public health emergency, representatives said.

In addition, the state Department of Health has regulatory authority only over the water system outside the schools. Seattle Public Schools in January turned off water fountains and began supplying bottled water in schools built before 1997 — those more likely to have lead pipes or fixtures.

Q: Generally, what can be done to reduce the risk of consuming lead-contaminated water, especially in older homes?

A: The Centers for Disease Control and Prevention recommends running the water for at least 15 seconds before using it for drinking or cooking. Don't drink hot water from the tap; run it cold, then heat it for drinking, cooking or, especially, for baby formula.

Q: Is there a way to have home water tested for lead?

A: Yes, commercial laboratories will perform the test. Also, for $17, the Environmental Quality Institute at the University of North Carolina, Asheville, will send you a test kit to return samples for analysis. The institute researches drinking-water quality nationwide. Visit www.leadtesting.org

Warren King: 206-464-2247 or wking@seattletimes.com