News Coverage
Tainted milk raises concerns
Published June 23, 2004
A Yuma-area researcher is broadening his studies of the possible impact of a rocket fuel chemical contaminating the Colorado River even as an environmental group announced that the same chemical has been found in milk in California.
Tuesday's announcement of the milk study by the Environmental Working Group is the latest development in the ongoing dispute over perchlorate, a leftover from the Cold War that has been seeping into the Colorado River and contaminating the water source for millions of people.
Colorado River water also irrigates 1.4 million acres of farmland in Southern California and Arizona, including Imperial County, California's leading alfalfa producer for that state's dairy cows.
The EWG reported it found perchlorate in 31 of 32 samples of milk in the Los Angeles area. The organization also said that tests by the state of California - obtained through a Freedom of Information request - found perchlorate in all 34 samples analyzed.
''Perchlorate exposure is more widespread than we have been led to believe,'' said Bill Walker, vice president for the West Coast office of the EWG.
The EWG did not call for Californians to stop drinking milk or giving it to their children. However, the group contends that a tougher standard is needed to protect developing fetuses and small children, who Walker said are at greater risk from perchlorate because it can disrupt thyroid function among the very young and cause mental retardation.
Whether perchlorate also is present in milk produced in Arizona is the subject of testing being conducted by the Food and Drug Administration, said Mike Billotte, a spokesman for the Arizona United Dairy Association. "I'm waiting for the FDA results," he said Tuesday when asked for comment on the EWG study.
The debate continues on the actual health risk of perchlorate, whether from drinking contaminated water or eating food grown with it. The National Academy of Science has been charged with evaluating data and establishing a federal standard, which is expected sometime this year.
Meanwhile, in March, California health officials adopted a public health goal of 6 parts per billion for drinking water. The Arizona Department of Health Services has set what it calls a health-based limit of 14 parts per billion for drinking water.
In the last nine months perchlorate levels in Yuma's drinking water supply have ranged from 1 to 5.7 parts per billion - all within the California health standard, said Charles Sanchez. A University of Arizona scientist based at Yuma Agriculture Station, he has been researching perchlorate levels in produce grown with Colorado River water for the last two years.
The perchlorate in the Colorado River is a legacy of 1950s-era rocket fuel plants near Las Vegas. The same chemical - from a variety of sources - also has been found in water supplies in 22 states across the nation.
That is the subject of the latest study now being conducted by Sanchez. This week, he embarked on a trip to collect 400 samples of produce from a number of states. The survey is funded with a $75,000 grant from Kerr-McGee Chemical Corp., operator of one of the Las Vegas plants.
Sanchez and University of California toxicologist Bob Krieger also received a $400,000 grant from the U.S. Department of Agriculture Food Safety Program to "conduct an aggressive and comprehensive assessment." The two scientists have been working collaboratively for two years to determine the levels and risk factors of perchlorate in lettuce and other vegetables grown in Yuma County and Southern California.
So far, Sanchez said, levels found in leafy vegetables "are appreciatively less than in drinking water at the California public health goal." That means, he explained, people would have to eat nine servings of lettuce to get exposure to what California considers an unsafe level in drinking water.
Other vegetables tested even lower, often with no detectable perchlorate or levels too low to quantify, he said.