Air Date: Week of December 4, 1998
Pesticides -- those poisons designed to kill bugs, weeds, and other forms of life that many people find undesirable -- are increasingly being tested directly on human beings. Until recently, most of the testing was on laboratory animals. This upsurge in experiments on humans has prompted a review panel at the U S Environmental Protection Agency to ask if the procedures are necessary or ethical. John Rudolph has our report.
CURWOOD: This is Living on Earth. I'm Steve Curwood. Pesticides, those poisons designed to kill bugs, weeds, and other forms of life that many people find undesirable, are increasingly being tested directly on human beings. Until recently most of the testing was on laboratory animals. This upsurge in experiments on humans has prompted a review panel at the US Environmental Protection Agency to ask if the procedures are necessary or ethical. John Rudolph has our report.
(A supermarket: rolling carts, ambient voices)
RUDOLPH: A glittering display of fresh fruits and vegetables greets shoppers at a supermarket in Washington, DC. Shiny red applies, fragrant melons, and plump green grapes are piled high, tempting the eye and the palate. But take this produce home and make a fruit salad, and you may be adding some ingredients that you hadn't counted on.
HETTENBACH: There's a high potential for pesticide exposure from some of these foods.
RUDOLPH: Todd Hettenbach is with the Environmental Working Group. It's an organization that wants to see reductions in the amount of pesticides found on fruits and vegetables.
HETTENBACH: Some of the worst for a particular class of pesticides that we care about, the organophosphate pesticides, are apples, grapes, peaches, and pears.
RUDOLPH: Watchdog organizations like the Environmental Working Group aren't the only ones concerned about pesticides in food. In 1996 Congress was so worried about unhealthy pesticide residues that it overwhelmingly passed a sweeping new law. The Food Quality Protection Act aims to dramatically cut the amount of pesticides many Americans are exposed to. The Act mainly tries to protect people that scientists believe are especially susceptible to pesticide poisoning: babies, young children, and pregnant women.
HETTENBACH: There is a precautionary principle that's been built into this law that says that if you're not sure, you need to err on the side of safety. And what we're dealing with, is we're dealing with pesticides that affect the nervous system, affect the brain, and children, since their brains are developing, are especially vulnerable.
RUDOLPH: But something unexpected has happened as the Federal Government has tried to put the Food Quality Protection Act into practice. The Act builds in an extra margin of safety for pesticides on food. Acceptable pesticide levels are now supposed to be 10 times smaller than they've been in the past. The only way around this is if reliable scientific evidence shows that a less strict safety factor can be used. Now, in what many see as an attempt to skirt the law, some pesticide manufacturers are increasingly testing their products directly on human beings. The human test results are intended to support the manufacturers' contention that pesticides are safe at levels that were permitted before the new law was passed. These experiments appear to be legal under Federal rules governing all types of human testing, including drug trials. But many people wonder, are they ethically and scientifically sound:
(A phone is dialed; another rings; a busy office)
RUDOLPH: The Environmental Protection Agency in Washington is one place where concern is growing over human testing of pesticides. Gary Guzy is the EPA's top lawyer.
GUZY: It may be that this is a technique that is being used to avoid the consequences of the application of some of the tougher standards of the new law, by instead of doing testing as traditionally has been done on animals, doing the testing directly on humans. And the consequence of that may be that companies are trying to make an argument for somewhat less stringent regulation of pesticides.
RUDOLPH: Under the Food Quality Protection Act, the EPA is responsible for setting new acceptable exposure levels for hundreds of different pesticides. So far, human test results make up only a tiny fraction of the scientific evidence that's been submitted to the EPA. Even so, the EPA's Gary Guzy says human testing is on the rise and it poses unique ethical problems.
GUZY: We're very, very concerned that humans not be inappropriately subjected to environmental and health insults in a way that cannot be justified. It is really difficult to construct a rationale for allowing extensive testing of humans when there aren't clear benefits, when there may not be fully informed consent, when the risks may not be fully known, and when some of those risks may not be reversible.
RUDOLPH: This is the first time that the EPA has clearly articulated its concerns over human testing. In the past the Agency didn't encourage human studies, but it didn't automatically reject them, either. The EPA can't say exactly how many human studies are currently being conducted. But according to published reports, pesticides made by several different companies are now being tested on volunteers, mainly healthy adult males, primarily at 2 laboratories in Britain. The volunteers are asked to swallow capsules, or cups of juice, containing pesticides. The tests can last for a few weeks. For their trouble volunteers have reportedly been paid between $500 and $1,500. Pesticide manufacturers argue that human studies provide valuable scientific information on the safety of pesticides, information that is not always available from tests on laboratory animals.
McCARTHY: I think you can always say, or safely say, that more knowledge is always better. Otherwise we're arguing on the basis of hypothetical and theoretical considerations.
RUDOLPH: John McCarthy is a scientist with the American Crop Protection Association, a group representing companies that make and sell pesticides. McCarthy believes that human test data could lead to changes in the acceptable exposure levels of one very large and important category of pesticides: organophosphates. They're sprayed on a wide range of food crops, and a number of organophosphates have been linked to cancer. According to McCarthy, human studies could show that Food Quality Protection Act standards for organophosphates are too strict.
McCARTHY: In the case of the Food Quality Protection Act, the use of animal information for this class of compounds results in a very conservative estimate of what a safe level would be.
RUDOLPH: McCarthy argues that the only way to find out if safety levels for organophosphates are too stringent is to test them on humans. But he points out human testing does not mean giving pesticides to people to intentionally make them sick.
McCARTHY: These are not toxicity studies. These are studies at levels at which there are no effect in animals, and we want to see if that is indeed the same case in humans.
RUDOLPH: Despite industry assurances that human pesticide experiments are safe, many people believe they are unnecessarily risky. David Wallinga is a physician who works with the Natural Resources Defense Council.
WALLINGA: I tell you, I have to draw a real distinction between different kinds of human studies. There are epidemiologic studies, for example, that look at people that have been dosed accidentally. And I think that we're obliged to try to learn from those people, to try to learn what the long-term health effects are of these toxic chemicals. But that's a far cry from doing a prospective study, a study that looks forward, and to intentionally dose people who may or may not be informed enough to participate in a study, and then to use that as a basis for determining the levels at which these chemicals should be regulated.
RUDOLPH: But are there situations where human testing of pesticides is appropriate? To answer this question, the EPA is looking to other government agencies with years of experience supervising and evaluating human experiments. Officials from the Food and Drug Administration and the National Institutes of Health have been named to a panel that will attempt to develop a human testing policy for the EPA. However, these agencies face their own ethical dilemma right now. There's a growing sense that the Federal rules governing human drug tests are out of date. That greater oversight is needed to protect people who participate in drug trials. If the EPA adopts the current procedures for monitoring drug experiments and applies them to human testing of pesticides, it will be heading down a well-worn path. The danger is that in catching up with other government agencies, EPA could be implementing a system that's already inadequate. For Living on Earth, I'm John Rudolph.
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