Lettuce in Stores May Be ContaminatedApr 28, 2003 | The Salt Lake Tribune Lettuce grown in the fall and winter months and sold in grocery stores nationwide may contain higher levels of toxic rocket fuel than is considered safe by the U.S. Environmental Protection Agency, according to a study released today.
In one of the first tests of perchlorate in supermarket produce, 18 percent of lettuce samples contained detectable levels of perchlorate, and an average serving of the contaminated samples contained four times more than the EPA says is safe in drinking water, said officials from the Environmental Working Group (EWG), a Washington, D.C., advocacy organization.
The EWG estimates that by eating lettuce, 1.6 million American women of childbearing age, a population of great concern, are exposed daily from October to March to more perchlorate than the EPA's recommended safe dose.
Perchlorate, which looks like table salt, is used in manufacturing rocket fuel and other explosives. Scientists have linked consumption of the toxic chemical to thyroid disorders. In fetuses, infants and children, disruptions in thyroid hormone levels can cause lowered IQ, mental retardation, loss of hearing and speech and motor skill deficits.
In January and February, the EWG brought 22 commercial lettuce samples for analysis by scientists at Texas Tech University at Lubbock. Samples included prepackage and head lettuces, adults and baby greens, organic and conventional lettuces from several different distributors. Four of the samples contained measurable levels of perchlorate: averaging 70 parts per billion, according to the study.
California has proposed what state officials consider a safe level of perchlorate of two to six parts per billion, and hope to set the nation's first standard on the chemical by 2004. The EPA's draft proposal is stricter at 1 part per billion.
"If the perchlorate levels in our samples are representative, exposure is not just a problem for people in areas where the water is contaminated," said Bill Walker, West Coast vice president of EWG. "It's a national concern for everyone who buys winter lettuce at the grocery store."
Walker said the study confirms previous tests on greenhouse-grown lettuce seedlings by the EPA and field-grown vegetables by a San Bernardino, Calif., farm where irrigation water supplies were contaminated by defense contractor Lockheed Martin's abandoned rocket-testing facility. The EWG's tests were from lettuce likely grown in Southern California or Arizona.
Dennis Downs, director of the Utah Division of Solid and Hazardous Wastes, said state and federal officials are unsure exactly how much risk perchlorate poses when ingested and what limits should be set for the chemical.
"We'll likely see some standards set," said Downs. "We're closely watching what California does, and we'll be interested to examine this new study."
The chemical has forced the shutdown of hundreds of wells in California, and high doses have been detected in the lower Colorado River, the main water source of 20 million people in California, Arizona and Nevada.
In Utah, three sources of underground water are known to have perchlorate contamination. The one from Hill Air Force Base is the target of a Superfund cleanup program.
The second, near Thiokol, west of Brigham City, is spreading south into an area where there are several ranches.
And the third, around Alliant Techsystems (formerly Hercules) facilities in West Valley City and Magna, has shown up in a few drinking wells in the Magna area but is negligible by the time it is mixed with water from other wells, officials have said.
The EWG is calling for cleanup of perchlorate contamination of the Colorado River; more testing for the toxic chemical in drinking water and irrigation sources; and stopping the Bush administration's proposal to exempt Department of Defense sites from environmental regulations that includes perchlorate cleanup.