Health Highlights: April 14, 2008

In a U.S. government-funded study, researchers spread sludge made from treated industrial and human waste on the yards of nine low-income black families in Baltimore to test whether the sludge would protect children from lead poisoning, theAssociated Pressreported.

The families were told the sludge was safe and never informed about any possibly dangerous elements. In exchange for allowing the sludge to be spread in yards, the families received food coupons and new lawns, according to documents obtained by theAP.

The researchers said the sludge (leftover solid wastes from treatment plants) reduced the children's risk of lead-related brain or nerve damage. The phosphate and iron in sludge can bind to lead and other hazardous metals in soil. This means that, if a child eats contaminated soil, the harmful metals will pass safely through the body. The study was published in the journalScience of the Total Environmentin 2005.

However, many experts are skeptical about this claim. While the sludge can bind to lead in soil, "it's not at all clear that the sludge binding the lead will be preserved in the acidity of the stomach" when it's eaten, said soil chemist Murray McBride, director of the Cornell Waste Management Institute.

He questioned why the families weren't told about possibly harmful ingredients in the sludge and why low-income people were chosen for the research.

"If you're not telling them what kinds of chemicals could be in there, how could they even make an informed decision. If you're telling them it's absolutely safe, then it's not ethical," McBride told theAP.

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Gene Discovery May Lead to New Treatments for Iron Disorders

The discovery of a gene (TMPRSS6) that causes a rare form of iron deficiency may help in the development of new ways to treat iron disorders in the general population, according to researchers who studied five families with iron-refractory iron-deficiency anemia (IRIDA).

The families all had a variety of mutations in TMPRSS6. Deficiency of the TMPRSS6 protein results in overproduction of a hormone called hepcidin, which inhibits intestinal absorption of iron,Agence France-Pressereported.

The finding suggests that drugs designed to stimulate TMPRSS6 production may help some patients with anemia, particularly those with hepcidin overproduction. On the other hand, a drug that blocks TMPRSS6 production could help patients with iron overload disorders by increasing levels of hepcidin in order to limit intestinal iron absorption.

The study was published online Sunday in the journalNature Genetics.