The Organic Option - Centre d'agriculture biologique du Canada

The Organic Center Critical Issue Report Page
March 2008 Pesticide Dietary Risks 19
explain the cultural and biological practices that
will be used to prevent pest problems, and specify
the pest population thresholds or damage criteria
that must be exceeded before an application is
made.
Certifiers review and approve these organic
system plans before the growing season begins.
During annual inspections, pesticide use records
are among the most carefully inspected
documentation. Any deviation in pesticide use
patterns from the approved organic system plan
raises a red flag. Certifiers can impose additional
restrictions on a particular grower if they feel
OMRI-approved pesticides have been relied on
too heavily, because of inadequate attention to
preventive practices. Conventional growers face
no such requirements and oversight.
A. The Toxicity of Pesticides
Allowed in Organic Production
All pesticides are “toxic” to at least some organism,
at least to the extent that the pesticide somehow
kills, weakens, blocks reproduction, strengthens a
plant’s defenses, or repels a pest away from a
crop. Otherwise, a farmer would not pay money
to buy a pesticide, nor waste the time and effort
required to apply it.
When most people talk about the toxicity of
pesticides, they are usually referring to toxicity to
people, or mammals. The job of pesticide
regulators is complicated by the fact that different
types of pesticides are toxic to different classes of
organisms. Some products, like the synthetic
pyrethroid insecticides, are extremely toxic to
small aquatic invertebrates, but are not very
acutely toxic to people or birds.
the high-risk organophosphate (OP) and
carbamate insecticides that are among the riskiest
products used in production agriculture.
For organic farmers, spinosad is the first new,
highly effective insecticide approved for use on
organic farms that works just as well, or better
than many conventional insecticides. Despite its
relatively high cost, many organic fruit and
vegetable farmers have incorporated spinosad in
their organic system plans, and some appear to
be using it heavily. The only two samples of
cranberries that tested positive in 2006 for
spinosad were organic, and one contained
residues over the tolerance.
While far less risky to most organisms than the
OPs and carbamates, spinosad is among the
most toxic pesticides ever applied to bees. All
farmers must be disciplined in choosing when and
where, and how to apply spinosad, to assure that
foraging bees are not in the vicinity. If they are
during or soon after an application of spinosad,
they are not likely to survive the day.
Still, risks to humans clearly drive most pesticide
regulatory decisions. Virtually all the pesticides
cancelled, suspended, or driven off the market by
EPA have fallen out of favor because of risks to
humans. When the EPA identifies a significant
risk to some other class of organism, steps are
usually imposed through product reformulation or
labels to reduce, or mitigate those risks.
Pesticide manufacturers often market pesticides
that are toxic to people in a granular form to
reduce human exposure, but this increases bird
risks as a result (granular insecticides sometimes
appear to be small seeds to birds).
The important and very effective new biochemical
insecticide spinosad is approved for both
conventional and organic crop uses. It is a costeffective
alternative for conventional farmers to