Health, Environment Groups Warn Government Ignores Scientific Evidence of Higher Risk to Children
SAN FRANCISCO (March 2, 2006) -- Newborn infants are as much as 65 to 164 times more vulnerable than adults to a pair of common agricultural pesticides, according a study published today by researchers at the University of California. That means current government safeguards may not provide adequate protection for young children, say medical experts from the Natural Resources Defense Council (NRDC) and the Pesticide Action Network of North America (PANNA).
The new study looking at the chemicals chlorpyrifos (Lorsban) and diazinon -- which are used on many common crops including almonds, lettuce, peaches, grapes, tomatoes and soybeans -- appears in the journal Pharmacogenetics and Genomics.
NRDC is filing a brief tomorrow in a related lawsuit charging the U.S. Environmental Protection Agency (EPA) with failing to protect children from hazardous pesticides.
"Children are born with lower levels of our bodies' natural defenses against toxic pesticides," said Dr. Gina Solomon, M.D., a physician and senior scientist at NRDC. "Unfortunately, the officials responsible for keeping kids safe are ignoring the clear scientific evidence confirming that we need stronger protection for the most vulnerable among us."
The UC Berkeley scientists have been studying Latina mothers and their children in California's Salinas Valley agricultural region since 1998, taking blood samples from 130 women and their babies and analyzing them for a key enzyme (known as PON1) that normally helps detoxify the class of common insecticides known as organophosphates. The researchers analyzed the form and levels of the enzyme to predict the women and children's sensitivities to the pesticides.
When the scientists compared across the entire group, the most sensitive newborns were 65 times more sensitive to diazinon and 131 to 164 times more sensitive to chlorpyrifos. In addition, the study revealed that susceptibility varies significantly even among adults and children. For example, the women varied in susceptibility to diazinon by a factor of 14, whereas variability among the children was 26-fold. In the case of chlorpyrifos, sensitivity varied by as much as 35-fold among mothers, and as much as 65-fold among newborns. The researchers also found that the newborns had consistently lower levels of the protective enzyme than the mothers, making them about four times more sensitive, on average.
When mothers are exposed to organophosphate pesticides, previous research has shown that their children are likely to suffer low birth weight, premature birth, and other problems.
For example, the same group of researchers found that mothers with higher pesticide levels are more likely to give birth earlier (similar to the effect of maternal smoking), and their babies were more likely to have abnormal reflexes. A team of researchers at Columbia University reported that children whose mothers were exposed to these same chemicals were likely to have smaller weight and length at birth. Another study showed that low enzyme levels, coupled with detectable levels of chlorpyrifos in pregnant women, is associated with significant reduction in babies' head size -- a factor related to children's subsequent cognitive abilities.
Banned at Home, Widely Used on Farms
EPA banned chlorpyrifos and diazinon for household use in December 2001 and December 2002 respectively, largely due to their hazards to children, but allowed continued use on agricultural crops. More than 1.5 million pounds of chlorpyrifos were used in California in 2003. The top uses were on cotton, alfalfa, almonds and walnuts. More than 500,000 pounds of diazinon were used in California in 2003, mostly on lettuce, peaches, almonds, prunes and spinach. Nationwide, the organophosphate pesticides account for 70 percent of all insecticides used, with 73 million pounds sold in 2001.
In 2001, the most recent year for which EPA has reported data, about 20 percent of all foods for sale had residues of one or more organophosphate pesticides. The highest residues of chlorpyrifos tend to show up on apples from New Zealand, grapes from Chile, tomatoes from Mexico and domestically grown soybeans. (See the EPA website.)
"We're all exposed to pesticides in the foods we eat," said Margaret Reeves, Ph.D., senior scientist at the Pesticide Action Network of North America. "But farmworkers and the fenceline communities in agricultural areas are hardest hit by the use of these chemicals. The federal government has ignored these affected groups when it sets safety standards. This research clearly demonstrates the need for urgent measures to protect these communities and the food we eat."
In a lawsuit filed last August, NRDC and the Northwest Coalition for Alternatives to Pesticides accused the EPA of failing to protect children's health as required by law, and as demonstrated by science. The litigation follows EPA decisions establishing new tolerances for several pesticides in dozens of different foods, including fruits, vegetables, milk, eggs, meat, cereal grains and vegetable oils. In each case, the agency had failed to apply a child-protection factor as required by the 1996 Food Quality Protection Act. The case is being heard by the 9th U.S. Circuit Court of Appeals in San Francisco.
An NRDC backgrounder about pesticide risks and the Food Quality Protection Act is available here.