News Coverage
Perchlorate level too high in lettuce crop, group says
Published April 28, 2003
Winter lettuce grown in Yuma and California's Imperial Valley may be contaminated with unsafe levels of a chemical used to make rocket fuel.
If what the Environmental Working Group claims is true, everything from the lettuce leaf slapped onto a fast-food burger to the heaping salads consumed by vegetable lovers could be affected.
But the health risk is being debated.
The Environmental Working Group, a Washington, D.C.-based non-profit that has an office in Oakland, advises women of child-bearing age, and especially those who are pregnant or seeking to become so, to restrict their lettuce intake until the water used to irrigate lettuce crops is cleaned up or no longer used.
But a spokesman for the Arizona Department of Environmental Quality said the level of the chemical, perchlorate, in the water is lower than allowable limits set by the state.
"We would have no reason to believe it's unsafe to eat the lettuce," said DEQ spokesman Patrick Gibbons.
The group says four of the 22 lettuce samples it sent for independent analysis contained levels of perchlorate that registered at four times the federal standard for the chemical in drinking water.
There is no standard for perchlorate levels in food.
DEQ sampled the water in the Colorado River and Central Arizona Project canals in 1999 and found the level of the chemical at 9 parts per billion. The state allows up to 14 parts per billion. Federal limits range from 4 to 18 parts per billion.
Perchlorate can impair thyroid function, disrupting hormone formation and blocking the body's ability to take up iodine, a key nutrient. In infants and small children, whose bodies are still developing, the health effects can range from lowered IQ to loss of hearing and speech and impaired motor skills.
Three years ago, the Arizona Department of Health Services looked at the issue of perchlorate in the water by studying results from the state's newborn screening program. It found slightly elevated levels of the thyroid-stimulating hormone in some Yuma babies.
Bill Walker, a spokesman for the Environmental Working Group, said, "We're very sensitive to not wanting to cause a food scare here."
That's why, Walker said, the group released its report after the winter-lettuce season ended and lettuce from those areas was no longer in grocery stores.
The group also refused to identify the lettuce it submitted for testing at Texas Tech University, other than to say it was purchased at seven northern California grocery stores in January and February.
Rae Chornenky, legislative liaison for the Arizona Department of Agriculture, said the department is interested in the study but could not answer whether it is safe to eat lettuce or other food irrigated by water containing perchlorate.
She said more research is needed, but added, "We've had no change in our understanding of the safety of that lettuce."
The report points to a former perchlorate manufacturing plant operated by Kerr-McGee southeast of Las Vegas as the source of contamination. The chemical leaked into Lake Mead and worked its way down the Colorado River, which is used to irrigate the food crops grown in Yuma and the Imperial Valley.
Walker said the group is using its findings to call for a speedier cleanup of Lake Mead and the Colorado River.
The group also wants more government action, from testing irrigation water for perchlorate to compensating farmers and landowners who might lose production and see a drop in property values if the contaminated sources are shut off.
The group is calling on the U.S. Food and Drug Administration and the U.S. Department of Agriculture to conduct a study of perchlorate in the U.S. food supply and make its findings public.