Copyright 1999 The Christian Science Publishing Society
The Christian Science Monitor
January 14, 1999, Thursday
SECTION: USA; Pg. 2
LENGTH:
877 words
HEADLINE: How ethical is testing pesticides
on people, EPA asks
BYLINE: Peter N. Spotts, Staff
writer of The Christian Science Monitor
DATELINE:
WASHINGTON
HIGHLIGHT: Using human subjects will
make chemicals safer, say supporters.But critics worry about potential side
effects.
BODY: For years, companies
have tested pesticides on animals to ensure chemicals meet federal environmental
standards. Soon, however, it may become increasingly common for humans to join
mice at the lab dining table. The US Environmental Protection Agency is now
considering whether to form guidelines for how and when humans can be used to
test pesticides. As it does, the agency is confronted with some of the most
profound ethical questions it has ever faced. Under such tests, volunteers would
ingest diluted pesticides to help determine the level at which a compound no
longer has an observable health effect. Using human subjects isn't new. For
example, the EPA requires companies to find out how much of the chemicals
workers pick up as they mix, load, and apply pesticides. Such tests expose
humans to chemicals, but people are not required to ingest them. The tests
represent a tiny fraction of the toxicology and safety studies submitted by
companies. But now, pressure is mounting to use humans to ingest pesticides in
toxicity experiments. The impetus comes from the
Food Quality
Protection Act of 1996, which mandates a 10-fold reduction in the
current level of pesticides that can remain on food. The EPA must review more
than 9,000 pesticides on the market to ensure they meet new safety standards.
One-third of those chemicals must be reevaluated by this year. Concerned that
the new standards may reduce the use of some products and force others off the
market, chemical companies are slowly turning to private labs to test a
compound's toxicity directly on people. While subjects to date have not
displayed any long-term physical harm, some have complained of short-term
symptoms. Supporters argue that using humans represents the best scientific
approach to determine how toxic the chemicals are to people. Animal studies,
they say, involve uncertainties that human studies could erase. Critics counter
that it's unethical to ask people to swallow pesticides - and risk potential
side effects - for the sake of chemical company profits. What's clear is that
some companies are already beginning to use humans as test subjects without
waiting for federal guidelines. In 1997, a lab in Manchester, England, conducted
three related tests for Amvac Chemical Corp., based in the city of Commerce,
Calif., according to a study by the Environmental Working Group. Subjects were
given doses of a neurotoxic insecticide dissolved in corn oil. The British
newspaper The Guardian reported in August on tests under way at a private lab in
Scotland. In 1992, the French chemical company Rhone-Poulenc turned to the same
Scottish lab to test the insecticide aldicarb on human volunteers. "This is a
very sensitive issue," says John McCarthy, vice president for scientific and
regulatory affairs with the American Crop Protection Association in Washington.
But using animals in tests leads to dose limits with safety margins based on
uncertainty factors. Human test subjects "can remove one uncertainty factor."
Noting that some people see such tests as an industry tactic to justify using
more pesticides, McCarthy says the results - if they show the products don't
meet the new safety standards - could just as well build a case for tighter
restrictions on companies. Ultimately, he holds, testing pesticides on humans is
no different from testing the toxicity of new drugs on humans; both types of
compounds are merely a collection of chemicals. FROM a regulatory standpoint,
however, one key difference is that strong federal guidelines exist for testing
the toxicity of new drugs to ensure the experiments are scientifically sound and
ethically conducted - that volunteers are fully informed about how the study
will be performed and the risks involved. "We have no test guidelines in regard
to humans" and pesticide tests, says Richard Hill, a science adviser at the
EPA's Office of Prevention, Pesticides, and Toxic Substances. In response to
that lack, the EPA convened an ethics advisory panel last month to help the
agency sort through the ethical tangle surrounding pesticides and human test
subjects. Some participants wonder if scientifically adequate human tests for
pesticide toxicity can ever be designed. Human-based tests, for example, look
for short-term reactions. "You can be sure about the acute effects, but not
about the long-term or environmental effects," says Jeffrey Kahn, a biomedical
ethicist at the University of Minnesota's Center for Biomedical Ethics in
Minneapolis. Others, such as the Environmental Working Group's Melissa Haynes,
point out that human-based studies for pesticides could never attract enough
subjects to give the results any statistical validity. She and other critics
note that the participants so far all have been adults and most have been male,
raising a problem in trying to interpret the results for children and pregnant
women. Moreover, asking someone to risk physical discomfort to test a new drug
is more defensible than asking someone to risk the effects of a pesticide, just
so a farmer can apply more to his fields, some ethicists say. "Pesticides are
not therapeutic agents," observes Eric Meslin, executive secretary of the
National Bioethics Advisory Commission.
LOAD-DATE: January 13, 1999