Greater risk in formula than breast milk.

• Position: Arsenic - Brief article

Formula-fed infants have higher arsenic levels than breast-fed infants, and breast milk itself contains very low arsenic concentrations, it has been found by researchers at Dartmouth College, Hanover, N.H.

"This study's results highlight that breast-feeding can reduce arsenic exposure even at the relatively low levels of arsenic typically experienced in the U.S." says co-lead author Kathryn Cottingham, professor of biological sciences. 'This is an Important public health benefit of breast-feeding."

The researchers measured arsenic in home tap water, urine from six-week-old infants, and breast milk from women. Urinary arsenic was 7.5 times lower for breast-fed than formula-fed Infants. The highest tap water arsenic concentrations far exceeded the arsenic concentrations in powdered formulas but, for the majority of the study's participants, both the powder and water contributed to exposure.

"We advise families with private wells to have their tap water tested for arsenic," says senior author Margaret Karagas, professor of community and family...