“The motivation of people doing the research matters,” adds Jeffrey Kahn, a bioethicist at the University of Minnesota in Minneapolis and a member of the EPA advisory panel. “To ignore that is to ignore a big part of whether you think something is ethical or not.” Doing tests on human subjects for the purpose of circumventing legislation or enhancing profits doesn’t pass muster, he says. “I think under very few circumstances is it ethical to take healthy people and dose them with poison.”
Industry representatives argue that the ethical and scientific procedures they currently use for human pesticide tests are no different from those employed in clinical trials of drugs. “There is no sort of lower standard or different standard used for pesticide products,” says Angus Cameron, a former manager of the firm Inveresk Research International in Scotland, where many of the human tests have been conducted. The companies maintain that the EPA has in the past reviewed test protocols and accepted their results in evaluating risk. They also say there has been no significant increase in the number of human tests carried out since the food quality act was passed.
The EPA panel tried to stake out a middle ground. It named circumstances under which human testing would be ethical: if information on health risks is not available by any other means, and it could “promise reasonable health benefits to the individual or society at large.” At the same time, the panel insisted that children should “in no case” be part of such studies.
Two panel members lambasted the contradictions in this stance. “If children are different, then what information can adult dosing provide that is of use to set standards for protecting children?” wrote pediatricians Herb Needleman of the University of Pittsburgh School of Medicine and Routt Reigart of the Medical University of South Carolina in Charleston in a minority report.
Unable to build a consensus, the EPA last year asked the National Academy of Sciences to conduct an 18-month review of the issue. The academy’s report is due this month. Among other things, it could help the EPA devise strict standards for human pesticide tests as well as measures for auditing them.
In the meantime, we’re all research subjects in the great pesticide experiment. Every apple we eat, every stroll through the park ratchets up our cumulative load of neurotoxins. An ongoing study of thousands of Americans by the Centers for Disease Control and Prevention found organophosphate metabolites in the urine of the majority of survey participants—evidence they had been exposed to the pesticides within days of testing. Concentrations in children ages 6 to 11 were often twice as high as in adults.
“Whether organophosphate pesticides at the levels of the metabolites reported here are a cause for health concern is not known,” the study cautions. “More research is needed.”
Pesticides in Food Each year the Food and Drug Administration goes shopping for their Total Diet Study, a survey of pesticides and other contaminants in the food Americans eat. The FDA staff buys 250-plus kinds of food in three cities located in each of the country’s four geographic regions. After preparing the food, the agency screens it for traces of contaminants. The screen, which is far more sensitive than methods used in other programs monitoring pesticide use on foodstuffs, quantifies traces present in parts per million; an equivalent ratio is one gram (.035 ounce) per 1.1 tons of food. Year after year the Total Diet Study finds that the same five chemicals top the list of pesticides most frequently found in the sampled foods. Two of the five, DDT and dieldrin, are organochlorines that have been banned in the United States for more than 25 years. Their perennial appearance indicates their persistence in the soil here or their continued use on crops imported from other countries. A third organochlorine on the list, endosulfan, is still used in the United States. The remaining two pesticides are the organophosphates chlorpyrifos-methyl and malathion. Since 1996 the EPA has put partial bans on the use of 28 of the 49 organophosphates registered with the agency. And in 2001 the agency began a separate study to track the amount of organophosphates in domestically grown fruits and vegetables that play a large role in children’s diets. The good news is that the number of new pesticides with safer—and less biologically durable—active ingredients has risen sharply over the past 15 years. —Sarah Richardson |
