San Francisco Chronicle
September 24, 2005


By Deborah K. Rich

"You need regulation when you have a design flaw." -- Ted Schettler,
Science & Environmental Health Network

We're busy. We've got a lot to buy, and we don't have time to analyze
every purchase. But we'd better keep our brains turned on when we
reach for ant and roach sprays, weed killers and flea and tick
powders. These are all pesticides whose long-term effects are little
understood at best and detrimental to human and environmental health
at worst, despite being registered by the EPA.

By definition, pesticides inhibit the functioning of species or kill
them outright. The problem is, of course, that our nervous, digestive
and reproductive systems have more in common with rodents and insects
and other pests than we've been in the habit of thinking. We also
drink the same water, breathe the same air and eat many of the same
foods that they do. So do songbirds, spring peepers, honey bees and
other species we like.

A small battalion of Environmental Protection Agency scientists works
to temper the lethality of pesticides before they enter the
marketplace. Companies must register their pesticides with the EPA
before putting them on the market in the United States, a process that
requires companies to submit dozens of exposure studies and toxicity
tests, costing about $4 million to $8 million to complete in the case
of food-use pesticides.

From fatal doses to doses that cause deformities in nontarget species
-- and in the rats, rabbits, hens and dogs that serve as proxies for
humans -- the EPA calculates tolerance levels for pesticide residues
and establishes guidelines for use. The EPA bears the responsibility
for deciding how much we can kill without killing ourselves. As
consumers, we have to decide whether to accept the EPA's judgment.
Unfortunately, there are plenty of reasons not to.

Since its inception in 1970, the EPA has had to play catch-up to the
marketplace. Many pesticide chemicals entered the marketplace in the
1950s (the ability to produce toxic chemicals advanced tremendously
during World War II). In 1988, amendments to the Federal Insecticide
Fungicide and Rodenticide Act required companies to reregister
pesticides in use before 1984 with the EPA. The reregistration process
evaluates old chemicals against current EPA test protocol. Of the 612
classes of pesticide chemicals to be reregistered, 132 have yet to be
re-evaluated and continue to be sold.

The EPA is further disadvantaged because there's no scientific method
to ferret out the effect of frequent sublethal doses of pesticides on
complex bodily processes. How much of a learning problem, for example,
should be attributed to neurological damage caused by low doses of
pesticides ingested in breast milk, how much to an early fall from the
bathroom stool and how much to a lack of appropriate intellectual

"So many of the adverse health effects of chemicals in general are
nonspecific, whether it's cancer or a learning disability," says
Schettler, science director for the Science & Environmental Health
Network. "Nonspecific meaning that they're not caused by a single
thing. There are actually very few diseases where you see disease and
you think of a single chemical or a single exposure. With breast
cancer, non-Hodgkin's lymphoma, leukemia, brain tumors, learning
disabilities, hyperactivity, epidemiological studies tell us that the
risk of those outcomes increases with exposure to certain chemicals
including pesticides, but they don't tell us that the chemicals caused
this disease in John or Mary Smith."

Without the science to identify and evaluate direct interactions, we
have only correlations between pesticide exposure and disease. A
resource guide for health care professionals published in 2000 by
Nobel Peace Prize-winning Physicians for Social Responsibility and
Californians for Pesticide Reform referenced more than 150 independent
studies linking pesticides with cancer, neurological damage,
reproductive and developmental hazards, and immune-system and
endocrine disruption.

But correlations don't prove a chemical guilty beyond a reasonable
doubt, and correlations, unfortunately, emerge only over time and with
use. "Another problem with the pesticide-registration process," says
Susan Kegley, senior scientist for Pesticide Action Network North
America, "is that we really don't learn what the effects are going to
be until it gets out there in wide use, because there are just so many
things and interactions that you don't think of. Pyrethroids (used for
pest control in homes and on lawns) are now being found in stream
sediments everywhere and killing off all the critters that live in the

Even if a connection between a pesticide and a health or environmental
problem becomes too compelling to ignore, the pesticides will remain
on store shelves for several years. The EPA must conduct reviews and
develop new test protocol. Companies will then be given a grace period
to retest their products. The pesticide can be sold as before
throughout this five- to 10-year process.

Poor test results may lead to a pesticide being restricted -- to use
by professional applicators, for example, or to use in some states but
not others -- rather than banned.

The case of dibromo chloro propane is illustrative. Used as a soil
fumigant, DBCP was first produced in the 1950s by Shell and Dow
Chemical. In the 1970s, DBCP was linked to male sterility among
workers in factories where the chemical was produced. By 1977, the
California Department of Food and Agriculture had banned the use of
DBCP. In 1979, the EPA followed suit, banning DBCP except for use on
pineapples. In 1985, nearly 15 years after the discovery of DBCP's
testicular toxicity, the EPA banned use of DBCP entirely. However,
even after the U.S. ban, the chemical was still sold into Central
America. Today, there is a lawsuit against the companies that produced
DBCP on behalf of thousands of sterile plantation workers.

There are more reasons to think for ourselves before purchasing a
pesticide. One is that, with the exception of acute toxicity tests
that determine the immediate effect of a single exposure to a
pesticide, the EPA registration tests are conducted on only the active
chemicals (the known toxins) in pesticides. But the pesticide
formulations also include so-called "inert" chemicals. These chemicals
might keep the toxin suspended in liquid or help it adhere to the
leaves of plants it is designed to kill. Inert ingredients can have
unforeseen impacts.

Schettler recalls a study of Canadian rivers conducted from 1975 to
1985: "Salmon were failing to return to some Canadian rivers.
Investigations were done, and it was found that the failure coincided
with aerial spraying for spruce budworm in New Brunswick. The
insecticide had gotten into the rivers. But what was interesting was
that it wasn't the active ingredient that caused the problem, it was
the surfactant (a chemical that reduces surface tension), which was a
weak estrogen, in the pesticide. The surfactant had interfered with
the capacity of the young salmon to smolt, which means to be able to
go from fresh to salt water. They have to be able to adjust to that
new environment, and that adjustment turns out to be an estrogen-
dependent mechanism. The surfactant disrupted the process so that when
the young salmon went into the salt water they all died."

The reasons for testing only the active ingredients are largely
economic: There are close to 900 registered active pesticide chemicals
in the United States, but there are 20,000 formulations on the market.
Companies continually reformulate their branded products, plus final
formulations are considered trade secrets, companies' proprietary

Consider also that, unless the mechanisms of active ingredients are
known to be additive -- meaning there could be an overdose even if the
individual pesticides are used correctly -- the EPA doesn't evaluate
the effect of exposure to more than one pesticide at a time. Yet we
ingest multiple pesticides just eating an average meal, and we walk
around with a cocktail of pesticides inside us. In 2003, the U.S.
Centers for Disease Control and Prevention reported that the average
person has 13 pesticides sloshing around inside his body at any given

So let's not get into too much of a hurry when buying pesticides.
Let's take the time to remember that we're buying toxins and that we
introduce poisons into our immediate surroundings when we use them.
And let's remember that regulating a problem doesn't make it go away.

Deborah K. Rich is a Monterey writer and olive rancher. E-mail her at

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