News Coverage
Perchlorate found in plants, animals at six sites in U.S. in 2001
STUDY: Pentagon funding was to cover habitats and food crops, but the food study wasn't completed.
Published May 10, 2003
The Air Force never learned whether food crops were absorbing a potentially hazardous rocket fuel component seeping from defense-industry plants and military bases. But military researchers found plenty of evidence that bugs, mice and plants were taking it in.
A study completed in June 2001 found the chemical perchlorate in soil, sediment, plants and animals at six areas around the nation, from Yuma and Lake Mead to the banks of the Potomac River in Maryland.
Researchers concluded that perchlorate is entering nature's food chain and that plants had the highest concentrations -- often higher than amounts found in soil or water. The study did not determine how the perchlorate affected the plants and animals.
The habitat research and a study of food crops grown with perchlorate-contaminated Colorado River water were to split $500,000 in Pentagon funds. But the habitat research consumed all the money, and the food study was never completed.
Such a study would help federal and state regulators who are trying to establish limits for perchlorate in drinking water.
"We try to account for the total exposure that a person would get in food and drinking water," said Allan Hirsch, a spokesman for California's Office of Environmental Health Hazards Assessment. His office is developing a public health goal for perchlorate that will guide state efforts to establish drinking water standards.
Without much science to go on, the state office estimated food might account for 20 percent of the perchlorate the public consumes. But if perchlorate is found to be widespread in food, it could prompt the state to lower its public health goal for the chemical, he said. The state currently is proposing a public health goal of 2 to 6 parts per billion in drinking water.
For the habitat study, researchers gathered 965 samples of insects, algae, cactus, deer mice, quail and other birds, mosquito fish, alfalfa, mesquite, grass and soil at six sites studied. Those sites included locations along the lower Colorado River from Palo Verde to Yuma, and in the Las Vegas wash that empties into Lake Mead. The lower Colorado River contains 4 to 9 parts per billion of perchlorate.
The chemical was found in many samples, including alfalfa grown in the Palo Verde area near Blythe. The amounts detected ranged from a few to thousands of parts per billion.
The alfalfa sample near Palo Verde, for example, contained 1,010 parts per billion of perchlorate. One sample of Bermuda grass in the Las Vegas wash had 90,000 parts per billion.