In the first-ever U.S. study of urinary arsenic in babies, researchers made the shocking discovery that formula-fed babies tended to have higher urinary arsenic levels than those that were breastfed.
The study also noticed that breast milk itself contained very low levels of arsenic, Dartmouth College reported.
A team of researchers measured arsenic in home tap water, the urine of 71 sex-week-old infants, and breast milk from nine women in New Hampshire. They found arsenic concentrations were 7.5 times lower in breast-fed infants when compared with formula-fed ones.
The highest concentrations of arsenic in tap water were much higher than levels in powdered infant formulas, but both formula and water were found to contribute to urinary arsenic levels in infants.
"This study's results highlight that breastfeeding can reduce arsenic exposure even at the relatively low levels of arsenic typically experienced in the United States," said lead author Professor Kathryn Cottingham. "This is an important public health benefit of breastfeeding."
Arsenic occurs naturally in bedrock and contaminates most well water across the globe. It has been linked to an increased risk of cancer and other diseases; exposure early in life is believed to contribute to fetal mortality, decreased birth weight, and diminished cognitive function. The Environmental Protection Agency (EPA) enforces a maximum arsenic level for public drinking water, but private well water does not fall under this regulation.
"We advise families with private wells to have their tap water tested for arsenic," says senior author Professor Margaret Karagas, principal investigator at Dartmouth's Children's Environmental Health and Disease Prevention Research Center. Added study co-lead author Courtney Carignan: "We predict that population-wide arsenic exposure will increase during the second part of the first year of life as the prevalence of formula-feeding increases."
The findings were published in a recent edition of the journal Environmental Health Perspectives.
