Common Pollutant Transported into Breast Milk
Study in rats also demonstrates perchlorate's effect on thyroidal iodine uptake
WEDNESDAY, Dec. 12 (HealthDay News) -- Perchlorate, exposure to which is common in the United States, is transported into breast milk by the sodium-iodine symporter and would affect thyroidal iodine uptake, according to the results of a study in rats published online Dec. 11 in the Proceedings of the National Academy of Sciences Early Edition.
Orsolya Dohan, M.D., from the Albert Einstein College of Medicine in the Bronx, N.Y., and colleagues examined whether perchlorate could be transported by the sodium-iodine symporter in addition to iodine.
The researchers found that the symporter could transport perchlorate both in vitro and into the breast milk of rats, and the effect of perchlorate on the rate and extent of iodine accumulation could be modeled mathematically. Unlike the transport of sodium and iodine, which generates a positive inward current, they note that the transport of sodium and perchlorate is electroneutral.
"That the sodium-iodine symporter actively concentrates perchlorate in maternal milk suggests that exposure of newborns to high levels of perchlorate may pose a greater health risk than previously acknowledged because perchlorate would thus directly inhibit the newborns thyroidal iodine uptake," Dohan and colleagues conclude.