News Coverage
Lettuce has trace of unsafe chemical
Survey of valley reveals perchlorate
Published November 30, 2004
A survey conducted between December 2003 and August by the U.S. Food and Drug Administration found traces of perchlorate, a toxic rocket-fuel chemical, in samples of Salinas Valley lettuce. The FDA has not determined any immediate health risk and does not advise consumers to alter their eating habits. The study can be found at www.cfsan.fda.gov/~dms/ clo4data.html.
Traces of a hazardous chemical have been found in lettuce grown in the Salinas Valley, according to a survey conducted between December 2003 and August by the U.S. Food and Drug Administration.
The survey, released Friday, says four types of lettuce -- green leaf, iceberg, red leaf and romaine -- were found to have amounts of perchlorate, a primary ingredient of solid rocket propellant. The chemical also is used in fireworks, leather tanning and the manufacture of paint and enamel, among other things.
To discover how much perchlorate might be absorbed into food from contaminated irrigation water, the FDA undertook the survey, finding levels ranging from 1 part per billion (ppb) in green leaf lettuce to 29.6 ppb in iceberg lettuce.
The U.S. Environmental Protection Agency reports that exposure to the chemical should not exceed 1 ppb in drinking water. Health officials in California have set a preliminary safety standard of 6 ppb for drinking water, according to the Environmental Working Group, an anti-pollution advocacy group.
"These numbers are very surprising to me," said Bob Roach, assistant agricultural commissioner for Monterey County.
Roach, whose department assisted the FDA in obtaining samples, said the findings are unexpected because there are no known sources of perchlorate contamination in Monterey County.
The FDA is gathering perchlorate data to determine if "any action might be needed to protect the public health," according to the Web site where the survey is posted, www.cfsan.fda.gov/~dms/clo4data.html.
The FDA survey follows an announcement by the Environmental Working Group in May 2003 that it found perchlorate traces in four heads of lettuce purchased in the San Francisco Bay Area.
That announcement rocked the lettuce world and had Salinas Valley growers hastening to assure consumers that lettuce grown here had no perchlorate contamination.
In May 2003, Eric Lauritzen, Monterey County agricultural commissioner, told The Salinas Californian, "It isn't a maybe when it comes to Central Coast lettuce. There's been adequate testing to ensure it (perchlorate) is not here."
As Roach did Monday, Lauritzen said then that there is no obvious source of perchlorate contamination in the Salinas area.
So far, the FDA is not advising consumers to alter their eating habits or those of their children to avoid exposure to perchlorate in lettuce.
If consumed in sufficient volume, perchlorate can affect the thyroid gland's ability to make essential hormones and lead to thyroid gland tumors, the survey Web site says.
The U.S. Department of Agriculture is exploring how plants absorb perchlorate. The survey Web site says that perchlorate can get into plants when they are irrigated with water containing it or through soil that has been exposed to water or fertilizer containing the chemical.
The survey also tested perchlorate levels in lettuce in other parts of California, including the Imperial Valley and Santa Maria, as well as Arizona, Florida, New Jersey and Texas.
The FDA also is studying perchlorate levels in bottled water and milk at various locations around the nation.