May 20, 2014
Pollinator Entry Point Suggestions from
Chuck Benbrook
1. Learn from, and leverage U.S. action, based on insights gained
in Europe.
The EU is carrying out a very significant experiment in 2014-2015 via
a moratorium on agricultural uses of the three major neonicotinoids.
There will be considerable effort invested across Europe by
beekeepers, scientists, and government agencies to document and
understand the consequences of the moratorium. Clearly, if evidence
emerges that pollinator health has improved significantly, the
pressure will build for: (a) making the EU moratorium permanent, and
(b) other countries to follow suit.
Someone with deep knowledge of these issues should be
asked/supported to closely track the impacts of the moratorium. This
can be done by tapping into the international network of NGOs,
scientists, and beekeepers which will be involved with assessing the
impacts, and/or via a fact-finding trip to several EU countries. If such
evidence emerges of substantial improvement, this will be critical new
information to support much more aggressive EPA action than
otherwise likely in the U.S.
It remains uncertain re whether the impacts of the moratorium will be
clear after one or two years, and whether the data and methods used
to judge impacts are widely accepted. Indeed, much is at stake in
how this largely technical/scientific debate unfolds. No one can
predict, as well, what new studies and insights might emerge in the
scientific literature (e.g., the new Alex Lu paper highlighting the
impact on hive health of cold temperatures over the winter).
2. Develop, vet, refine the pollinator relative pesticide risk index
under development by Pesticide Data Central (Kegley, Mineau,
Benbrook).
There are lots of lists of bee-toxic pesticides, but the science
supporting such lists is shallow and often weak. There are few
credible, lists of pesticides that pose little or no risk to bees. Clearly,
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a robust, science-based method is needed to rank relative pesticide
risks to pollinators, based on defined pesticide use patterns. Every
NGO working in this arena needs access to such a model and/or the
lists it will generate. Ecolable programs working to promote pollinator
health also will likely make use of such lists.
There are many ways to estimate relative bee risks, ranging from
very simple (e.g., LD-50s) to complex (models that take into account
formulations, sub-acute effects, multiple routes of exposure, and
how/when pesticides are applied). The model under development by
PDC will be among the most advanced in the world. It will support a
diversity of classification exercises, so that different groups can come
up with their own lists, based on their own subjective choices about
where and how to draw the line between low and moderate risk, or
moderate and high risks.
The PDC relative risk tool will not dictate how to draw such lines, nor
what factors should be taken into account in doing so. But once
those decisions are made, the model will be the most reliable way to
come up with the hard numbers that will determine where different
pesticides, and pesticide use patterns, land on the relative risk list.
While PDC is in a position to complete its relative risk tool in 2014,
the tool will cover and reflect only a subset of the risks faced by
pollinators. It will largely rest upon the ecotoxicological database
developed over many years of testing focused on the acute and sublethal pesticide impacts on bee mortality and health. More research
and investment will be required to:
 Introduce synergistic effects into the model (clearly important
given the 1,000-X or more increase in neonicotinoid toxicity to
bees also exposed to certain common fungicides);
 Incorporate impacts on hive health and viability, as opposed to
individual bee health; and
 Build into the model expert judgment based on emerging
science.
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3. Provide an overview of neonicotinoid uses and dietary
exposures and cumulative risks, and describe how the EPA’s
assessment of neonicotinoid toxicity is likely to change in light
of new science on neonicotinoid mammalian developmental
toxicity.
Few people understand how widely neonicotinoids are used and how
vital they have become, especially for corn farmers, and fruit and
vegetable producers. M2M, PDC, PAN, and/or Benbrook Consulting
Services has all or most of the data required to provide a thorough
accounting of neonicotinoid uses and dietary exposure levels since
the late 1990s. Both have risen steadily, with no end in site.
Someone needs to drive home why the new science on neonicotinoid
developmental neurotoxicity, coupled with the provisions of the Food
Quality Protection Act, should compel EPA to add an additional 10fold safety factor to the chronic Reference Doses of all
neonicotinoids. NRDC would be the perfect group to file a petition
calling for this specific action.
Estimates will be needed to determine whether this change will drive
current residues/exposure levels above EPA’s “level of concern.”
Initial steps should be made in conducting a cumulative risk
assessment across all neonicotinoid uses and exposure pathways.
This analysis will likely produce possible exposure levels well above
EPA’s “level of concern.”
4. How might synergistic effects alter the human risks posed by
neonicotinoids?
Multiple papers have documented dramatic synergistic effects in the
potency of neonicotinoid-fungicide combinations to bees (some over
1,000-fold). Some insights have been gained regarding the
mechanism behind observed synergistic effects. Research is
desperately needed to explore whether similar synergism can impact
mammalian toxicity.
A strong case can be made for synergistic research on neonicotinoids
plus fungicides, and neonicotinoids plus glyphosate, a herbicide
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which now leads to higher levels of dietary exposure than any other
pesticide (and possible any pesticide in history).
There are several simple and relatively cheap assays that can be
used to test multiple combinations of pesticides for possible
synergism. These assays will never prove a new risk, but are relied
on by toxicologists as screening tests, to determine whether more
complex and costly animal testing is warranted. A relatively modest
investment in this sort of research could identify potential new
instances of synergistic interaction, which could in turn open up
important new areas of research that might spare the nation a major
debacle down the road.
5. Identifying toxicity thresholds beyond which pollinator health will
always be in jeopardy.
There are several $64,000 questions that must be answered before a
sustainable solution can be found to the underlying ecological
realities undermining pollinator health. Significant progress can be
made on two with data and methods within which.
First, does it take more “kill power” to bring a crop to harvest in 2014
than it did two decades ago, and are pesticide-driven risks likely to go
up or down in the next two decades?
Second, at what level in the “kill power” trajectory of pesticide use will
it become essentially impossible to sustain pollinator health?
Many defenders of conventional agriculture argue that most, if not all,
dangerous pesticides have been removed from the market and that
farmers are using lower volumes of pesticides overall, and average
toxicity has gone down. There is considerable evidence to back up
these claims when linked to human risk, but such progress
sometimes comes at the expense of increasing risks to other nontarget organisms.
There are many ways to track pesticide use and risk. Risk
assessment methods and data are by far most robust in estimating
human risks, and in general, pesticides posing unacceptable risks to
humans have been replaced by “safer-to-humans” pesticides, many
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of which are much more dangerous to non-target organisms, and
especially other plants, insects, or animals. This is why in the last two
decades strong evidence suggests human dietary risks have dropped
by about one-half, while pollinator risk has increased, and probably
by a much larger margin.
We need a new “ruler” -- a method to quantify the organism-specific
“kill power” needed to bring an acre of crop X, Y, or Z to harvest.
From past work, I suspect that such a ruler will show at least a tripling
of “kill power” in the case of corn production systems from the 1970s
until today. I suspect the same will be true in many other crops.
This escalation in the kill power needed to bring a crop to harvest is a
direct measure of the sustainability of IPM systems. Bringing this
concept into the public dialogue is long overdue, and will help in
many arenas.
It may indeed be possible to empirically establish kill power
thresholds in cropping systems beyond which pollinators become,
first, vulnerable to periodic loses, and then likely to suffer significant
adverse impacts in most years, and finally, a threshold beyond which
they are unable to sustain populations. In some of U.S. agriculture, it
is fairly obvious we have already exceeded this last threshold.
This line of work, and the results it will produce, will hopefully refocus
attention on why, for example, a growing share of corn farmers now
need 3-6 Bt toxins in their corn, still spray a soil insecticide, apply 2-4
herbicides, and spray 1-3 fungicides, when two decades ago, virtually
all fields were harvested with fewer than three toxins applied.
The human side of this is also clear – why does the average apple,
strawberry, or sweet pepper today have 5 or more pesticide residues,
when 20 years ago few had more than 2?
The answers are actually pretty clear and entail a combination of
breeding for yield, more intensive and specialized cropping systems,
less crop rotation and biodiversity in farming areas, and the pursuit of
ever-higher yields of picture-perfect crops. Forcing soils and plants to
produce at today’s levels requires a degree of intervention – and
especially fertilizer and water – that creates pest heaven on earth.
And so farmers are locked into farming systems that require ever5
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higher “kill units,” and at some point along the trajectory, pollinators
will simply disappear.
A method to establish that threshold, and show where and why its
already been exceeded, would be powerful and help motivate change
across a wide swath of the sustainable agriculture agenda.
6. Bring insights to the U.S. from the successful prosecution of
Bayer in France.
A coalition of beekeepers and scientists brought a successful case in
a French court against Bayer about six years ago. During the case,
there was a deposition given by a Bayer scientist, in which he
admitted Bayer had used radio-labeled imidacloprid seed treatments
to "test" dose levels in plants. This is an explosive admission. Here is
why.
Bayer developed a simple, low-cost method to measure imidacloprid
levels inside plants following seed treatments by measuring radiolabeled imidacloprid in guttation droplets with a Geiger
counter. Hence, Bayer KNEW the imidacloprid would move out of the
plant via guttation droplets, and they also knew guttation droplets are
a favorite drinking water source of bees in the morning. I believe the
deposition is in French, or perhaps German, but somehow we need
to get it translated and presented to a U.S. audience. It is as close to
a smoking gun in terms of corporate culpability as I have ever seen.
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