Perchlorate in Water affects Lettuce Supply

U.S. Lettuce Supply Likely Contaminated With Rocket Fuel

Winter lettuce crops in California are contaminated with perchlorate, a component of rocket fuel, which can harm humans, especially infants and developing fetuses, according to a study.

Exposure to perchlorate, which is highly water-soluble, can cause mental retardation, loss of hearing and speech, and motor skill deficits in developing fetuses. The compound is a known contaminate of drinking water in 20 states and also contaminates the Colorado River, which irrigates 70 percent of the United States’ winter lettuce supply, according to the study.

In the study, researchers analyzed 22 commercial lettuce samples, including prepackaged and head lettuces, adult and baby greens, and organic and conventionally grown.

Four of the 22 samples tested contained perchlorate in excess of 30 parts per billion (ppb). The highest sample, mixed organic baby greens, had 121 ppb. In 2002, the Environmental Protection Agency found that perchlorate in drinking water poses health risks in concentrations above one part per billion.

Based on those results, the study researchers concluded that 1.6 million U.S. women of childbearing age are exposed each day to levels of perchlorate above the EPA's recommended safe dose from winter crops of lettuce alone.

According to the study, lettuce, which is being sold in U.S. supermarkets, absorbs and concentrates significant amounts of perchlorate from polluted irrigation water.

Moreover, close to 90 percent of the U.S. winter lettuce supply is grown in Southern California and Arizona with irrigation water from the Colorado River, which is contaminated with perchlorate.

However, several groups have come out against the EPA’s recommendation, including the Pentagon and several defense contractors, who could be responsible for billions of dollars in potential cleanup liability for perchlorate pollution, arguing that perchlorate is safe in drinking water in quantities 70 to 200 times greater than the EPA’s recommended safe dose.

Definitive data on the levels of perchlorate in U.S. produce was supposed to have been available years ago, however, the Defense Department reportedly would not fund the estimated $215,000 needed to collect samples of vegetables, leading some environmentalists to question whether the Defense Department really wanted to know if perchlorate was contaminating food.

According to one environmental scientist, "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."

Researchers of the current study say that their results are not conclusive due to their small sample size. However, they hope that their results will spur the federal government to conduct a more definitive study that will take a comprehensive look at the potentially widespread perchlorate contamination.

Wall Street Journal April 28, 2003

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More Rocket Fuel in Lettuce

Lettuce and other vegetables grown in fields irrigated by the Colorado River may contain higher amounts of toxic rocket fuel than is considered safe by the U.S. Environmental Protection Agency (EPA).

Leafy green vegetables grown with contaminated water store and concentrate potentially harmful levels of perchlorate, a thyroid toxin that is a main ingredient of rocket and missile fuel, according to tests.

Further, aerospace and defense contractor Lockheed Martin, a major user of perchlorate, reportedly knew as early as 1997 that vegetables stored high concentrations of the chemical, but did not release the information to health officials. There is also speculation that the Department of Defense may also have known, but did not warn other agencies, farmers or consumers.

Analysts recommend that the Food and Drug Administration (FDA) begin testing on vegetables grown with water from the Colorado River, and, if harmful perchlorate levels are confirmed, take immediate action to reduce contamination and keep the food off the market.

Additionally, farmers who are adversely affected by perchlorate contamination of their crops should be fully compensated for all economic losses.

Perchlorate has contaminated close to 300 drinking water sources and farm wells in California and an unknown number of sources in at least 15 other states. The chemical impairs the thyroid’s ability to take up iodide and produce hormones that are critical to proper fetal and infant brain development.

The EPA doesn’t plan to adopt national standards for perchlorate in drinking water until at least 2006, although elected officials in California are calling for faster federal action.

However, it appears that vegetables grown with perchlorate-contaminated water may pose more of a threat than drinking water.

According to a 1999 study of lettuce seedlings grown in perchlorate-contaminated water, perchlorate was accumulated in the leaves by factors of 100 times or more. The lettuce was able to take up and store 95 percent of the perchlorate in the water, which means that lettuce grown in water with even low levels of perchlorate could deliver doses far higher than the EPA’s provisional drinking water standard.

Despite preliminary research that suggests food is likely to be an equal or greater source for perchlorate exposure than drinking water, this hasn’t been reflected in the proposed drinking water standards, which would need to be substantially lower to account for the exposure coming from food.

Environmental Working Group June, 2003

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How much rocket fuel do you feel is safe for you and your family to drink in your drinking water? Government regulation and standards are slow to be put in place. People can drink a contaminated water for years before the EPA acts.