(April 28) -- A laboratory test of lettuce sold in California found that one in five samples contained percholorate, a toxic rocket-fuel ingredient that has polluted the Colorado River. Water from that river is used to grow much of the nation's winter vegetables. What should consumers be concerned about?
It's no exaggeration to say, the Colorado River is the lifeblood of our southwest region. The Colorado flows into Lake Mead at Hoover Dam, then flows out along the border of Arizona and California into Mexico. Colorado River water is diverted to irrigate tens of thousands of acres of farmland in California’s Imperial Valley. The produce grown on that land is shipped to grocery stores throughout southern Nevada and the rest of the country.
Now, a new test shows that Colorado River water, which is being contaminated by a rocket fuel ingredient in southern Nevada, may be contaminating fresh vegetables.
The specific vegetable in question is lettuce. Not just heads of lettuce but mixed greens too including organic.
It is certainly a surprise to consumers. We have long known about pesticides being used to grow fruits and vegetables but this new study found something far more dangerous -- a chemical called perchlorate.
The Environmental Working Group tested 22 un-named, types of lettuce from California: heads of iceberg lettuce, romaine--even bags of mixed greens. It found 4 of the 22 samples -- or 18 % -- had measurable levels of perchlorate--a common ingredient in rocket fuel.
Renee Sharp with the Environmental Research Group says, “Any average serving of these contaminated samples contained more than four times perchlorate than the EPA says is safe in a liter of drinking water.”
Though our lettuce comes from California, the Environmental Working Group says Southern Nevada is where the real problem is--specifically here at Lake Mead and along the Colorado River, where perchlorate is in the water.
That water flows directly to the Colorado River and is used to irrigate the farms in California.
Though health officials have long known of perchlorate's existence in our water supply, they have little experience with perchlorate in our food.
According to Steven Goode with the Clark County Health District “We're unsure of exactly what the true impact of this is.”
Steven Goode is the environmental health manager at the Clark County Health District. He says no government food alerts for lettuce have been issued, which means it will not be pulled from stores shelves.
If any tainted lettuce is in southern Nevada Goode says there's no way to clean it: “Lettuce, for instance, has a high, high concentration of water. It's primarily water. There isn't anything that you can do to wash it off.”
Although you can't wash it Goode says, at this point, it is still likely safe to eat and that the long-term health benefits of eating lettuce outweigh any short-term threats until further studies can be done. Those tests will be conducted by the Food and Drug Administration. I spoke to a representative in Washington today and he said a test with only 22 samples of lettuce isn't big enough to warrant a food alert. The FDA will conduct a large-scale study in the near future.
Is there any concern perchlorate could wind up in fruits and other vegetables? Absolutely, that is a big concern. But at this point, the only test we know of has been conducted on lettuce. And since lettuce is nearly all water it is thought to be a more likely host of perchlorate, since perchlorate is in our water supply.
Perchlorate is a chemical used to make rocket fuel. It can affect thyroid function, which regulates metabolism and growth. Because of that, pregnant women--especially their babies--are more vulnerable. In infants and children, contamination can lead to lowered IQ, mental retardation, and loss of hearing or speech.