Rocket-fuel chemical found in milk

USA Today (Society for the Advancement of Education), April, 2005

A thyroid-disrupting chemical may be more widespread than previously believed, as a study of store-bought and breast milk from across the U.S. by scientists at Texas Tech University, Lubbock, found perchlorate in every sample but one.

Perchlorate occurs naturally and is a primary ingredient in solid rocket fuel. The chemical, which has been showing up in many segments of the environment, can interfere with iodide uptake in the thyroid gland, disrupting adult metabolism and childhood development.

The researchers analyzed 47 dairy milk samples purchased randomly from grocery stores in 11 states, and 36 breast milk samples from women recruited at random in 18 states. Every sample of breast milk contained perchlorate, and only one sample of dairy milk contained no detectable levels. The average perchlorate concentration in breast milk was 10.5 micrograms per liter; in dairy milk, 2.0. No definitive national standard exists, although the Environmental Protection Agency had suggested a limit of 1.0 micrograms per liter in drinking water.