The D.C lead-poisoning episode,To learn

Washington, D.C. -- In a major exposé, Salon magazine has alleged that from 2004 to 2007 the Centers for Disease Control in Atlanta ignored -- whether inadvertently or not -- a major episode of lead poisoning in the District of Columbia that involved hundreds, perhaps thousands, of infants and children. The poisoning occurred from 2001 to 2004, when the level of lead in the tap water of some D.C. homes soared because of a switch from chlorination to chloramination.

In 2004, the CDC concluded that these elevated levels of lead did not constitute a public-health problem, but its analysis was based on incomplete data -- the test results for many affected children were not included. Based on that report, the CDC also told other water suppliers not to worry about elevated lead concentrations in drinking water like those that occurred in the District of Columbia.

The agency claims that it released its falsely reassuring report in 2004 because the missing lab reports -- almost half the total -- were all for children with blood-lead levels of less than 10 micrograms per deciliter (mg/dl).

But the CDC knew in 2004 that the peer-reviewed literature showed substantial harmful effects for lead concentrations below 10 mg/dl and that some of the most prominent independent scientists in the field, like Dr. Herbert Needleman and Dr. Philip Landrigan, were arguing for a much lower level. California, for example, had already set a much more stringent level.

Worse, when the CDC discovered that its findings had been incorrect, and that blood poisoning in the district had increased, it quietly released a new study to that effect in 2007. But until Salon blew the whistle, the agency made little effort to correct the record by publicizing the new data.

Unfortunately, the lead-poisoning episode isn't the only recent example of the CDC engaging in behavior that looks suspiciously like a cover-up. The agency was heavily implicated in the effort to avoid public exposure of the potentially lethal concentrations of formaldehyde in FEMA's toxic trailer scandal. The CDC also suppressed a study it had prepared showing toxic hot spots threatening citizens of the Great Lakes region -- and fired the scientist who prepared the report.

Congress is already investigating the D.C. lead-poisoning episode. It ought to dig deeper and find out what was really going on at the Centers for Disease Control during the past eight years. After three strikes, a watchdog agency like the CDC ought to be called out.