https://www.theguardian.com/environment/2016/sep/22/pesticide-manufacturers-own-tests-reveal-serious-harm-to-honeybees
[links in on-line article]
Pesticide manufacturers' own tests reveal serious harm to honeybees
Bayer and Syngenta criticised for secrecy after unpublished research
obtained under freedom of information law linked high doses of their
products to damage to the health of bee colonies
Unpublished field trials by pesticide manufacturers show their products
cause serious harm to honeybees at high levels, leading to calls from
senior scientists for the companies to end the secrecy which cloaks much
of their research.
The research, conducted by Syngenta and Bayer on their neonicotinoid
insecticides, were submitted to the US Environmental Protection Agency
and obtained by Greenpeace after a freedom of information request.
Neonicotinoids are the world’s most widely used insecticides and there
is clear scientific evidence that they harm bees at the levels found in
fields, though only a little to date showing the pesticides harm the
overall performance of colonies. Neonicotinoids were banned from use on
flowering crops in the EU in 2013, despite UK opposition.
Bees and other insects are vital for pollinating three-quarters of the
world’s food crops but have been in significant decline, due to the loss
of flower-rich habitats, disease and the use of pesticides.
The newly revealed studies show Syngenta’s thiamethoxam and Bayer’s
clothianidin seriously harmed colonies at high doses, but did not find
significant effects below concentrations of 50 parts per billion (ppb)
and 40ppb respectively. Such levels can sometimes be found in fields but
concentrations are usually below 10ppb.
However, scientists said all such research should be made public. “Given
all the debate about this subject, it is hard to see why the companies
don’t make these kinds of studies available,” said Prof Dave Goulson, at
the University of Sussex. “It does seem a little shady to do this kind
of field study - the very studies the companies say are the most
important ones - and then not tell people what they find.”
Prof Christian Krupke, at Purdue University in Indiana, said: “Bayer and
Syngenta’s commitment to pollinator health should include publishing
these data. This work presents a rich dataset that could greatly benefit
the many publicly funded scientists examining the issue worldwide,
including avoiding costly and unnecessary duplication of research.”
Advertisement
Ben Stewart, at Greenpeace, said: “If Bayer and Syngenta cared about the
future of our pollinators, they would have made the findings public.
Instead, they kept quiet about them for months and carried on
downplaying nearly every study that questioned the safety of their
products. It’s time for these companies to come clean about what they
really know.”
Syngenta had told Greenpeace in August that “none of the studies
Syngenta has undertaken or commissioned for use by regulatory agencies
have shown damages to the health of bee colonies”. Goulson said: “That
clearly contradicts their own study.”
Scientists also noted that the companies have been previously been
critical of the research methods they themselves used in the new
studies, in which bees live in fields but are fed sucrose dosed with
neonicotinoids.
In April 2016, in response to an independent study, Syngenta said: “It
is important to note that the colony studies were conducted by directly
feeding colonies with spiked sucrose, which is not representative of
normal field conditions.”
In 2014, commenting on another independent study, Bayer told the
Guardian the bees “are essentially force-fed relatively high levels of
the pesticide in sugar solutions, rather than allowing them to forage on
plants treated with” pesticide.
“If someone had done this type of study and found harm at more realistic
levels, the industry would have immediately dismissed it as a rubbish
study because it was not what happens naturally to bees,” said Goulson.
“So it is interesting that they are doing those kinds of studies
themselves and then keeping them quiet.”
Utz Klages, a spokesman for Bayer, said: “The study [Bayer] conducted is
an artificial feeding study that intentionally exaggerates the exposure
potential because it is designed to calculate a ‘no-effect’
concentration for clothianidin. Although the colony was artificially
provided with a spiked sugar solution, the bees were allowed to forage
freely in the environment, so there is less stress - which can be a
contributing variable - than if they were completely confined to cages.
Based on these results, we believe the data support the establishment of
a no-effect concentration of 20ppb for clothianidin.”
He said a public presentation would be made at the International
Congress of Entomology next week in which the new results would be
discussed.
A spokesman for Syngenta said: “A sucrose-based mechanism was used on
the basis that it was required to expose bees artificially to
thiamethoxam to determine what actual level of residue would exert a
toxic effect.”
Given the lower concentration usually found in fields, he said: “The
reported ‘no adverse effect level’ of 50ppb indicates that honey bee
colonies are at low risk from exposure to thiamethoxam in pollen and
nectar of seed treated crops. This research is already in the process of
being published in a forthcoming journal and is clearly already publicly
available through the FOI process in the US.”
Matt Shardlow, chief executive of conservation charity Buglife, said:
“These studies may not show an impact on honeybee health [at low
levels], but then the studies are not realistic. The bees were not
exposed to the neonics that we know are in planting dust, water drunk by
bees and wildflowers, wherever neonics are used as seed treatments. This
secret evidence highlights the profound weakness of regulatory tests.”
Researchers also note that pollinators in real environments are
continually exposed to cocktails of many pesticides, rather than single
chemicals for relatively short periods as in regulatory tests.
_______________________________________________
Sustainablelorgbiofuel mailing list
Sustainablelorgbiofuel@lists.sustainablelists.org
http://lists.eruditium.org/cgi-bin/mailman/listinfo/sustainablelorgbiofuel