Neurotoxic pesticides blamed for the decline of honeybees is also harming butterflies, worms, fish, and birds, and contaminating habitats worldwide which are crucial for food production and wildlife, scientists have concluded after a four-year assessment.
Societal regulations have not stopped habitats from being
poisoned, said the analysis, despite neurotoxic pesticides
already being held responsible for the global collapse in the bee
population.
“Undertaking a full analysis of all the available literature (800
peer reviewed reports) the Task Force on Systemic Pesticides – a
group of global, independent scientists has found that there is
“clear evidence of harm sufficient to trigger regulatory
action,” a press release accompanying the report noted.
Twenty-nine scientists from four different continents conducted
the study, which found the unmistakable evidence of the link.
“I think the only acceptable dose of this systemic pesticide
is just nothing – zero,” said Dr. Jean Marc Bonmatin, a
researcher at CNRS-CBM lab in France. “We are able, in this
laboratory, to detect very, very small amounts of these
neurotoxins. And as toxicologists, we are able to test these
toxicants on drosophila – on bees – and so on. So we are able to
see the effect of such tiny amounts of neurotoxins.”
The pesticides referred to in the report are neonicotinoids
(neonics) and fipronil. Farmers spend some US$2.6 billion on
neonicotinoids worldwide every year. They are used as a general
practice rather than a response to a pest problem.
“The majority of the pesticide doesn't go into the crop at
all,” said Professor Dave Goulson from the UK’s University
of Sussex, who contributed to the study. “More than 90 percent of
it goes elsewhere into the environment and they're really
persistent in the environment.”
Goulson said that cumulatively, we as humans are
“contaminating the global environment with highly toxic,
highly persistent chemicals.”
“If all our soils are toxic, that should really worry us, as soil
is crucial to food production,” he added.
Butterflies, bees, birds suffering...humans next?
In Marinduque, a province of the Philippines, the rural
population practices butterfly farming to encourage the sustained
pollination growth of local vegetation. “All the people here
in the rural areas depend on the butterflies, and continued use
of pesticides could destroy their livelihood,” said
Elizabeth Lumawig-Heitzmann, director of Romeo Lumawig Memorial
Museum.
In addition to butterflies, maintaining bee and insect
populations are necessary for the pollination of crops.
“These days many people are completely detached from nature –
they buy their food in a supermarket, they live in a
city...biodiversity is vitally important for us,” said
Bonmatin.
Bees are affected because chemicals hurt their ability to both
navigate and learn. Neonics can be 5,000 to 10,000 times more
toxic to bees than DDT – which itself has been banned in
agriculture.
“The classic measurements used to assess the toxicity of a
pesticide (short‐term lab toxicity results) are not effective for
systemic pesticides and conceal their true impact. They typically
only measure direct acute effects rather than chronic effects via
multiple routes of exposure,” the report found.
However, bees are not the only ones affected by the pesticides;
birds and mammals which feed on the insects, as well as worms,
are also harmed. Worms aerate soil, and chemicals can disrupt
their ability to tunnel properly.
Because birds eat insects and worms, declines in their
populations can also lead to a loss in the birds feeding on them.
The report also postulates that even eating only a few
contaminated seeds may kill birds directly.
Insecticides and pesticides seep into rivers and streams from the fields they are used on. "Microbes, fish and amphibians were found to be affected after high levels of or prolonged exposure," the report said.
“Overall, a compelling body of evidence has accumulated that
clearly demonstrates that the wide-scale use of these persistent,
water-soluble chemicals is having widespread, chronic impacts
upon global biodiversity and is likely to be having major
negative effects on ecosystem services such as pollination that
are vital to food security,” the study concluded.
The report is part of a special edition of thepeer-reviewed
journal 'Environmental Science and Pollution Research.'
The EU has already placed a three-year ban on using three
neonicotinoids (clothianidin, imidacloprid, and thiametoxam) on
flowering crops which bees feed on. However, they can still be
used on winter crops.
Pesticide manufacturers were critical of the study’s findings.
“It is a selective review of existing studies which
highlighted worst-case scenarios, largely produced under
laboratory conditions,” said Nick von Westenholz, chief
executive of the Crop Protection Association, before reiterating
the need to “protect pollinator health.”
According to Goulson, the focus has so far only been on
honeybees. “It’s clear that the impacts of neonics are more
profound than that,” he said, adding that the story
stretches beyond bees “to all wildlife that lives on
farmland.”