Government promises to rid the nation's food supply of brain-damaging pesticides aren't doing the job, according to the results of a yearlong study that carefully monitored the diets of a group of local children.The peer-reviewed study found that the urine and saliva of children eating a variety of conventional foods from area groceries contained biological markers of organophosphates, the family of pesticides spawned by the creation of nerve gas agents in World War II.
When the same children ate organic fruits, vegetables and juices, signs of pesticides were not found.
When the same children ate organic fruits, vegetables and juices, signs of pesticides were not found.
"The transformation is extremely rapid," said Chensheng Lu, the principal author of the study published online in the current issue of Environmental Health Perspectives.
"Once you switch from conventional food to organic, the pesticides (malathion and chlorpyrifos) that we can measure in the urine disappears.
Within eight to 36 hours of the children switching to organic food, the pesticides were no longer detected in the testing.
The study has not yet linked the pesticide levels to specific foods, but other studies have shown peaches, apples, sweet bell peppers, nectarines, strawberries and cherries are among those that most frequently have detectable levels of pesticides.
Death or serious health problems have been documented in thousands of cases in which there were high-level exposures to malathion and chlorpyrifos. But a link between neurological impairments and repeated low-level exposure is far more difficult to determine.
"There's a large underpinning of animal research for organophosphate pesticides, and particularly for chlorpyrifos, that points to bad outcomes in terms of effects on brain development and behavior," Dr. Theodore Slotkin, a professor of pharmacology and cancer biology at Duke University in North Carolina, said in the April 2006 Environmental Health Perspectives.
"It is appropriate to assume that if we -- human beings -- are exposed to (this class of) pesticides, even though it's a low-level exposure on a daily basis, there are going to be some health concerns down the road," said Lu, who is on the Environmental Protection Agency's pesticide advisory panel.
The EPA says it eliminated the use of organophosphates on many crops and imposed numerous restrictions on the remaining organophosphate pesticide uses.
Congressional concern that children were being harmed by excessive exposure to pesticides led to the unanimous passage of the Food Quality Protection Act. At its heart was a requirement that by 2006, the EPA complete a comprehensive reassessment of the 9,721 pesticides permitted for use and determine the safe level of pesticide residues permitted for all food products.
"As a result, the amount of these pesticides used on kids' foods (has undergone) a 57 percent reduction," said Jonathan Shradar, the EPA's spokesman.
What to do
While the gut reaction of some parents might be to limit the consumption of fresh produce or switch completely to organic food, Lu cautions not to make the wrong decision.
While the gut reaction of some parents might be to limit the consumption of fresh produce or switch completely to organic food, Lu cautions not to make the wrong decision.
"It is vital for children to consume significantly more fresh fruits and vegetables than is commonly the case today," he says, citing such problems as juvenile diabetes and obesity.
"Nor is our purpose to promote the consumption of organic food, although our data clearly demonstrate that food grown organically contains far less pesticide residues."
.... an all-organic diet is not necessary. He has two sons, 10 and 13, and he estimates that about 60 percent of his family's diet is organic.
"Consumers," he says, "should be encouraged to buy produce direct from the farmers they know. These need not be just organic farmers, but conventional growers who minimize their use of pesticides."
Understanding how fruits and vegetables grow can help guide the consumer, he says.
For example, organic strawberries probably are worth the money because they are a tender-fleshed fruit grown close to the dirt, so more pesticides are needed to fight insects and bugs from the soil. He adds apples and spinach to his list.
For example, organic strawberries probably are worth the money because they are a tender-fleshed fruit grown close to the dirt, so more pesticides are needed to fight insects and bugs from the soil. He adds apples and spinach to his list.
"It may also be money-smart to choose conventionally grown broccoli because it has a web of leaves surrounding the florets, resulting in lower levels of pesticide residue," Lu says.
ABOUT THE STUDY
Chensheng Lu's study was published this month in Environmental Health Perspectives (ehponline.org), a publication of the National Institute of Environmental Health Science. It was funded by the Environmental Protection Agency and used federal laboratories to confirm the accuracy of his findings.
Chensheng Lu's study was published this month in Environmental Health Perspectives (ehponline.org), a publication of the National Institute of Environmental Health Science. It was funded by the Environmental Protection Agency and used federal laboratories to confirm the accuracy of his findings.
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