News Coverage
Perchlorate threat looms for farmers
They want the FDA to quickly evaluate the risk to the public
Published July 25, 2004
When Merced County dairyman Tony T. Azevedo heard that a rocket fuel component was showing up in California milk, he immediately started working down a mental checklist of his herd's food and water sources.
Could his organic dairy's drinking water contain traces of the pervasive pollutant perchlorate? How about alfalfa purchased from other farms?
Azevedo assured himself that he was probably clean, but he didn't stop there. His co-op, Wisconsin-based Organic Valley, has commissioned a handful of tests nationwide to see whether its milk contains the compound linked to delayed mental development in children.
What's glaringly missing is definitive word from government authorities about the combined risk posed by the compound at levels at which it's being discovered nationwide in vegetables, water and milk. It will take several more months for a national picture to emerge even though perchlorate has been suspected in foods since the late 1990s.
The U.S. Food and Drug Administration is launching a dragnet of "high-priority" perchlorate tests this summer to gauge the extent of perchlorate in the nation's food supply. The food industry, legislators and environmental groups are waiting impatiently for results that won't be complete until 2005.
"If you say rocket fuel in milk, people get pretty upset," said Rachel Kaldor, executive director of the Dairy Institute, a Sacramento-based group of milk processors. "We need more information."
California's multibillion-dollar dairy sector was unnerved in June by news that separate studies done by the California Department of Agriculture and an environmental group found low levels of perchlorate in 63 of 64 milk samples taken statewide. Federal and state experts were quick to say that the levels discovered - 1 to 11 parts per billion - were not an imminent threat.
Such assurances didn't entirely allay concern. "It's time for the federal government to ... protect our children from exposure to this harmful chemical," Sen. Dianne Feinstein, D-Calif., said in a recent letter to health officials.
The issue already had some attention in Washington, D.C. - although the FDA's critics contend that the agency has reacted slowly.
The FDA's own tests on 20 milk samples confirm that perchlorate is present in milk across the country, but for now the agency is not recommending any dietary changes to avoid perchlorate. "Further studies are needed," said one agency statement.
In December, the FDA announced that it would do 500 "high-priority" perchlorate tests, including 150 on lettuce, 120 on milk, 55 on tomatoes, 45 on carrots, 45 on canteloupe and 35 on spinach.
The lettuce tests are done, with results to be posted on the FDA's Web site in several weeks. Now, the agency is doing the rest of its "food basket" tests, which could continue into 2005.
The Environmental Working Group has investigated perchlorate pollution for years and authored the June study that found widespread contamination in milk. Vice President Bill Walker in Oakland hasn't been impressed with the FDA's timeliness or transparency.
"We don't think their response has been adequate to match the potential severity of the problem," he said.
Terry Troxell, director of the FDA's Office of Plant and Dairy Foods, said the new round of tests will focus on areas such as the Colorado River Basin, where waters are known to contain perchlorate. The agency has not set a level at which it would bar foods from being marketed, nor have initial results in lettuce warranted agency alarm, Troxell said.
The FDA's food samples won't be a statistically rigorous assessment of the nation's food supply. "We are just trying to get a reasonable number (of samples) so we have a reasonable sense of the distribution of perchlorate," Troxell said.
The agency aims to combine food test results with data about consumption patterns to better understand if sensitive consumers, such as young children, are overexposed to perchlorate.
Perchlorate has been around for decades but has been of increasing concern since the late 1990s as it's been detected in an array of foods by increasingly sophisticated tests.
The National Academy of Sciences is currently assessing efforts by the U.S. Environmental Protection Agency to set safe levels for perchlorate in drinking water. That process, the centerpiece in the federal response to perchlorate, is expected to take at least until the end of the year.
Perchlorate can hamper the thyroid gland's ability to take up the essential nutrient iodide and make thyroid hormones. In addition, long-term perchlorate exposure could be dangerous for infants and children because thyroid hormone disruption is known to retard development.
Perchlorate contaminates more than 350 water sources in California, along with waters in 22 states. In the Rancho Cordova area, perchlorate pollution from rocket builder Aerojet has forced abandonment of several wells.
A variety of methods are being deployed and explored in California to treat perchlorate-contaminated wells - for instance, removing unwanted particles - but they can be costly.
The Colorado River is among the most polluted water bodies, the result of a shuttered rocket fuel plant that has been leaking perchlorate into the river. The river provides drinking water for millions of people and irrigates some of the nation's most valuable croplands.
Many suspect California's milk is tainted by alfalfa grown with Colorado River water, then fed to dairy cows. If perchlorate levels in milk turn out to warrant action, dairies likely would have to identify areas where feed is grown with untainted water.
Azevedo, the Merced County dairyman, gets water from Yosemite and feed from north state farms that aren't near known sources of perchlorate contamination. However, he figures some dairies won't be so lucky.
"This touches all our lives," he said. "If you eat at any time of the day, you are part of farming."
The dairy industry, larger in California than anywhere else in the country, pays close attention to anything that might turn off parents. "Any time that you have a compound that you didn't expect in any way to see in your product, you are concerned," said the Dairy Institute's Kaldor.
She said sales numbers don't show consumers shying away from milk because of the attention to perchlorate in June.
The institute and others are pressing politicians to clean up tainted wells and other water supplies, find replacement water sources and stop the compound from entering waterways. "That is where it has to be fixed," Kaldor said. She also emphasized the need for a national perchlorate health standard, saying it would help address consumer concerns.
Almost immediately after the June report, dozens of consumers started calling the phone number on Organic Valley milk cartons. They asked questions about whether the co-op's milk had been tested and how perchlorate affects pregnant women.
Trader Joe's, the Monrovia-based grocery chain, wanted some of the same answers, prompting Organic Valley to take test milk in the regions of the country where it has member dairies, including California.
"We need to respond to our consumers' fears - and we need to know," said Theresa Marquez, marketing director for Organic Valley in La Farge, Wis.
Even though there's a chance that perchlorate could scare consumers away from milk, Azevedo welcomes the attention. He said it's important for people to realize that pollution can cause problems for decades and eventually permeate the food chain. "You don't have to be a rocket scientist to figure that out," he said.