Women who nurse their infants may think they are doing their babies a favor, but new research has raised concerns about potentially harmful contamination. The contamination, researchers say, may also be suppressing iodide in the milk below recommended levels.
The study at Texas Tech University in Lubbock was the first-ever U.S. survey of the chemical percholorate in human breast milk. It found levels as high as 92 parts per billion - 20 times higher than the dose recommended as safe by a National Academy of Sciences committee.
Perchlorate is a man-made material that has been used in association with high-performance rocket fuels. It has been found recently in municipal water supplies in several areas of the country as the result of leaks from storage tanks.
The scientists said they were more troubled by the low levels of iodide found in the milk, and they speculate that might be due to the increased levels of perchlorate.
"Perchlorate inhibits iodide uptake and may impair thyroid and neurodevelopment in infants," the researchers said.
On the basis of limited available data, the study says iodide levels in breast milk may be significantly lower than it was two decades ago. It says recommended iodine intake by pregnant and lactating women may need to be revised upward.
Just where is the extra perchlorate coming from? That remains a mystery. Researchers have ruled out drinking water, but conclude it has to have some external source. Some team members say they think it must be coming from food.
