Study Indicates Children’s Pesticide Risk Higher

Preliminary results from the first government study of the cumulative effects of a group of pesticides show that they may be harming brain development and function in a small percentage of children.

The data, released last week by the Environmental Protection Agency, will guide federal regulators as they decide whether to further limit applications of the pesticides, known as organophosphates. They are commonly used to kill insects on a wide variety of crops--including strawberries, peaches, spinach, celery and apples--and in households and home gardens.

Experts fear that the toxins could cause short-term problems, such as lagging attention, or create long-term afflictions, such as nerve injuries and Parkinson’s disease.

Children face higher risks than adults because they often eat a higher percentage of their body weights in their favorite fruits and vegetables, and their nervous systems are still developing.

Depending on how the EPA analyzes the new data, the percentage of 1- to 5-year-olds exposed to unacceptable levels of the toxins could range from 0.3% to 10%, or 57,000 to 1.9 million children.

The test results send “a strong signal to the EPA that it owes parents of this nation some stiff action to make sure the fruits and vegetables are safe for kids,” said Charles Benbrook, a consultant who has focused on pesticide regulation for three decades.

The EPA is scheduled to complete its final report on the risks of organophosphates next year, at which time it may restrict uses of some of the pesticides.

“With these tools, we will continue to ensure that the United States has the safest, most abundant food supply in the world,” Assistant EPA Administrator Steve Johnson said.

Johnson stressed that it is premature to draw conclusions from the preliminary results and said the overall food supply is safe.

The American Crop Protection Assn., the pesticide industry trade group, declined to comment on the 3,000-page study, saying it had not yet analyzed the data.

“Basically, what it means--if this analysis proves to be correct--[is that] there are thousands of children who are being exposed every day to these toxic chemicals at levels that pose a serious risk to their health,” said Erik K. Olson, senior attorney for the Natural Resources Defense Council (NRDC).

But until the agency finalizes its study, Olson said, “we don’t think it means people should stop feeding children fruits and vegetables--or panic.”

Organophosphates inhibit the function of cholinesterase, an important chemical that enables nerve cells to communicate with each other.

“The same mechanism that makes these effective as bug killers are potential mechanisms for toxicity in people,” said Lynn Goldman, a pediatrician and professor of environmental health sciences at Johns Hopkins University.

The experts conceded that a lot remains to be learned about the effect these toxins have on humans.

“The real concern is that there is the potential for acute effect and subsequent developing nerve injury, Parkinson’s disease or other neuro-degenerative disorders,” said Alan H. Lockwood, a physician and professor of neurology at the University of Buffalo.

The EPA compiled the data from a variety of sources, including the Agriculture Department’s surveys of food eaten by individuals of different ages. The study considered pesticide exposures from food, households and drinking water and determined that drinking water was not a major contributor to risk.

The EPA studied the brains of female rats exposed to a variety of the pesticides to quantify their combined effect on varying age groups.

Environmentalists and physicians praised the EPA for its sophisticated and thorough study and challenged the agency to aggressively mitigate the risks posed to children.

The 1996 Food Quality Protection Act required the EPA to analyze the cumulative effect of pesticides on humans. The agency agreed to a timetable for producing the study as a settlement to a lawsuit filed by the NRDC, other environmental groups and the United Farm Workers Union.

A key decision facing the EPA is whether to apply a safety factor for children--a multiplier used to account for their higher sensitivity--when determining safe levels of exposure to the pesticides. The law requires the agency to use a tenfold safety factor unless the EPA can prove the safety of a lower amount.

One- and 2-year-olds appear to face the highest risk, with 3- and 5-year-olds following closely behind. Three in 1,000 children ages 1 or 2 face risks higher than the EPA usually considers acceptable, according to the data.

Physicians and environmentalists who advise the EPA believe that the agency likely will apply a safety factor when setting its regulations. The level of multiplier used could show that 3% or even 10% of 1- to 2-year-olds are exposed to unacceptable risk.

Such a decision would have significant implications for growers. If no safety factor is used, the agency could probably pare away some residential uses--such as No-Pest Strips--and restrict pesticide use on some key crops, Goldman predicted.

But if a tenfold safety factor is used, pesticide use will face much greater restrictions.

Carl Winters, a toxicologist at UC Davis, said the report showed exposure levels that were surprisingly low. Winters, who is skeptical of environmentalists’ concern about the danger of pesticide exposures, does not believe that the data will motivate the EPA to make significant changes in pesticide regulations.

Since 1996, the EPA has eliminated many uses of organophosphates, including most indoor residential uses. The new data showed that the greatest household exposure comes from anti-pest strips and a crack-and-crevice anti-bug treatment. Both products use dichlorvos, or DDVP. As with the food exposures, estimated risks appear higher for children than adults.