Perchlorate and Iodide in Dairy and Breast Milkla Sweden Dokuchaev Central Soil Museum Birzhevoy Pr 6 St Petersburg 199034 Russia USDA Forest Service Northeastern Research Station P O Box 640 Durham New Hampshire 03824 USDA Forest Service Northeaster

摘要

Perchlorate inhibits iodide uptake and may impair thyroid and neurodevelopment in infants.Recently,we unambiguously identified the presence of perchlorate in all seven brands of dairy milk randomly purchased from grocery stores in Lubbock,TX.How widespread is perchlorate in milk? Perchlorate in 47 dairy milk samples from 11 states and in 36 human milk samples from 18 states were measured.Iodide was also measured in a number of the samples.Perchlorate was detectable in 81 of 82 samples.The dairy and breast milk means were,respectively,2.0 and 10.5 mug/L with the corresponding maximum values of 11 and 92 mug/L Perchlorate is present in virtually all milk samples,the average concentration in breast milk is five times higher than in dairy milk.Although the number of available measurements are few at this point,for breast milk samples with a perchlorate content greater than 10mug/L,the iodide content is linearly correlated with the inverse of the perchlorate concentration with a r~2 of >0.9(n = 6).The presence of perchlora'te in the milk lowers the iodide content and may impair thyroid development in infants.On the basis of limited available data,iodide levels in breast milk may be significantly lower than it was two decades ago.Recommended iodine intake by pregnant and lactating women may need to be revised upward.