News Coverage
Just Ask
Published February 1, 2005
Q: I recently read that most milk in northern California contains perchlorate, a chemical used in rocket fuel. Do you know anything about this?
Mia Laurence, Fairfax, California
Perchlorate, the primary ingredient in rocket fuel, can pose risks of thyroid disorders, particularly for infants and developing fetuses. Perchlorate has been found in drinking water in 22 states and in samples of milk from northern and southern California. According to the Environmental Working Group (EWG), half of 32 samples of northern California milk tested by the state's agriculture department contained perchlorate levels deemed unsafe in drinking water. Dairy cows have absorbed perchlorate from alfalfa grown with contaminated water from the Colorado River. Concern first arose in 1998 when the Quechan tribe of Yuma, Arizona, found perchlorate in lettuce crops irrigated with water from the river, which feeds as much as 1.4 million acres of farmland and provides drinking water for Los Angeles, Phoenix, Las Vegas and other western cities.
The source for the Colorado's contamination is believed to be a now-closed Kerr-Mcgee defense plant near Las Vegas. But perchlorate also has been found in drinking water in areas across the country, from Kansas to New York City. In Tewksbury, Massachusetts, residents have been told not to drink the water due to contamination by trace amounts. In a recent study, the Pentagon found the chemical on 14 soon-to-be-closed military bases nationwide.
Perchlorate in milk and produce is just beginning to be tested for by the FDA. "Getting milk tested may be more difficult because it is a complex biological fluid and the testing lab must have experience," notes Annie Jarabek, a special assistant at the EPA's National Center for Environmental Assessment. In the meantime, a recent study funded by the EWG turned up what researchers called "significant levels" of perchlorate in the urine of dairy cattle in Texas and Kansas.
What You Can Do
*To find out if there's perchlorate in your water, check your water utility report, go to www.epa.gov/safewater/dwinfo.htm or see www.thegreenguide.com/doc.mhtml?i=101&s=threesteps.
*The EPA advises that pregnant women, parents of young children and people with thyroid or immune-system problems ask their doctors about safe consumption of liquids, including water (and, presumably, milk).
For more information, check these resources: www.ewg.org/issues/perchlorate/index.php.
FDA questions and answers on perchlorate: vm.cfsan.fda.gov/~dms/clo4qa.html.