Rocket Fuel Residues Found in Lettuce

The Wall Street Journal
May 2003

Rocket Fuel Residues Found in Lettuce
by Peter Waldman


The Bush administration has imposed a gag order on the U.S. Environmental Protection Agency from publicly discussing perchlorate pollution, even as two new studies reveal high levels of the rocket-fuel component may be contaminating the nation's lettuce supply.

The lettuce studies, one published [April 28] by a nonprofit environmental group and one in final preparation by an EPA laboratory in Athens, Georgia., address a crucial question in the current process of developing a federal drinking-water standard for perchlorate: whether Americans are ingesting the chemical from food sources in addition to drinking water. The answer, according to both studies, strongly suggests they are, which means that any eventual drinking-water standard will have to be that much stricter to account for the other sources of perchlorate exposure.

Perchlorate pollution in drinking water has become a major concern in some 20 states across the country, after an EPA recommendation last year that found perchlorate in drinking water poses dangers to human health, particularly to infant development, in concentrations above one part per billion.

The Pentagon and several defense contractors, who face billions of dollars in potential cleanup liability for perchlorate pollution, vehemently oppose that EPA health-risk assessment, arguing perchlorate is safe in drinking water at levels 70 to 200 times higher than what the EPA says is safe. In January, U.S. Sen. James Inhofe, (Rep.- Oklahoma.) chairman of the Senate's Environment and Public Works Committee, weighed in on the industry's side with a long list of questions and criticisms of the EPA's report.

The White House recently proposed a bill in Congress, in the name of military "readiness," that would effectively exempt the Pentagon and defense industry from much of their potential liability for perchlorate cleanup.

In another step, the White House Office of Management and Budget intervened last month to delay further regulatory action on perchlorate, by referring the health debate to the National Academy of Sciences for review, according to people familiar with the matter. Pending that study, which could take an additional six to 18 months, the EPA ordered its scientists and regulators not to speak about perchlorate, said Suzanne Ackerman, an EPA spokeswoman.

The gag order prevented EPA scientists from commenting or elaborating Friday on the two lettuce studies, which show lettuce, available in U.S. supermarkets, appears to absorb and concentrate perchlorate from polluted irrigation water in significant amounts. Other scientists familiar with the studies said both are limited in scope and are only suggestive, not conclusive, on the question of whether Americans are consuming perchlorate in food.

According to these scientists, definitive data on the perchlorate content in U.S. produce — specified as a top EPA and Pentagon research priority in the late 1990s — were supposed to have been available at least two years ago. But in 2000, after much time and effort had gone into designing a perchlorate study plan with the U.S. Department of Agriculture's Pesticide Data Program, the Defense Department refused to fund the roughly $215,000 needed to collect vegetables for sampling, said Cornell Long, who heads perchlorate research on food sources for the Air Force.

"In a perfect world, we would have that farm gate data now" on vegetable content, Mr. Long said. "Everybody thought it was a good idea."

Mr. Long attributed the Pentagon's decision not to fund the study to bureaucratic issues involving budget cycles. Some environmentalists, however, say the Defense Department simply didn't want to know if perchlorate was in the U.S. food supply because of liability concerns.

"If they can spend $1 million on a cruise missile, it seems kind of ridiculous they won't spend $200,000 to see if our food is contaminated with rocket fuel," said Renee Sharp, a staff scientist with Environmental Working Group in Oakland, California, which initiated its own lettuce study instead.

Using private funding, the environmental group paid Texas Tech University, of Lubbock, Texas, to test 22 lettuce samples purchased in January and February in the San Francisco Bay Area. It chose the two winter months because nearly 90% of the nation's winter lettuce supply is grown in the desert in Southern California and Arizona with perchlorate-tainted irrigation water from the Colorado River.

The results: Four of the 22 samples tested were found to contain perchlorate in excess of 30 parts per billion, with the highest — "mixed organic baby greens" — registering 121 ppb. After a flurry of mathematical extrapolations, the group concluded that 1.6 million U.S. women of childbearing age — the population of greatest concern — are exposed daily to more perchlorate than the EPA's recommended safe dose from winter lettuce alone.

"We don't claim this study is conclusive," said Ms. Sharp, its primary author. "We're saying, 'Isn't it scary we only took 22 samples and found so much perchlorate in four of them?"'

The EPA's own study, which was completed and peer-reviewed several weeks ago but has yet to be publicly released pending final adjustments, showed that lettuce grown in a greenhouse with perchlorate-contaminated water absorbs and concentrates the chemical at varying rates depending on leaf location. The study, reviewed by The Wall Street Journal, found the outer leaves of the lettuce, which the study's authors wrote are usually not eaten, concentrated perchlorate by a factor of 17 to 28, meaning the outer leaves contained 17 to 28 times more perchlorate in them than did the water used to irrigate the plants. The concentration factor for the "emerging head" — the part people usually eat — was three to nine, the study found.

Hence, if those results are found to be applicable to winter lettuce grown with Colorado River water, which contained between three and ten parts per billion of perchlorate, the perchlorate concentration in the edible leaves could range as high as 90 ppb — fairly close to the 72 ppb average perchlorate level that the Environmental Working Group found in its supermarket survey. The group says that level, for lettuce consumers, is four times the EPA's recommended daily dose for perchlorate.

"The studies have indicated we have reason for concern," says Allen Jennings, director of the USDA's office of pesticide management policy in Washington. "That's why it's critical to get as many foods as possible from the real world to find out."


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