from Sunday Herald, 08 August 2010
The UK government is under mounting pressure to ban a toxic pesticide
after new evidence suggested it could be to blame for the catastrophic collapse
of bee populations.
A Dutch scientific study says that bees could be poisoned by long term exposure to small concentrations of nicotine-based insecticides known as neonicotinoids. They are widely used by British farmers to kill insects that damage crops.
Because of concerns that they may be wiping out bees, their use has been banned or restricted in France, Germany, Italy and Slovenia. So far, however, the British government has resisted calls for a ban.
According to beekeepers, honeybee populations in the UK crashed by nearly a third in 2008. The implications are alarming, as bees contribute £200 million a year to the UK economy and pollinate one in every three mouthfuls of food that we eat.
The crash has sometimes been labeled “colony collapse disorder”, and its causes are disputed. But some scientists argue that neonicotinoids, which paralyse insects by attacking the nervous system, are implicated.
The new study is by Dr Henk Tennekes, a consultant toxicologist from Zutphen in the Netherlands. Published in the latest edition of the journal, Toxicology (subscription required), it says that very small quantities of toxins can be hazardous in the long run.
“The long term risks may have been seriously underestimated,” Dr Tennekes told the Sunday Herald. Neonicotinoids should be banned as a precautionary measure, he argued.
“These insecticides may leach from soil into ground and surface water and are long-lived in water and soil. Prolonged exposure of invertebrates is likely to occur, and under such circumstances, minute quantities may intoxicate aquatic and terrestrial organisms.”
This could explain the disappearance of bees, Dr Tennekes said. “If long-term studies were to be carried out, far lower concentrations may turn out to be hazardous.”
He was backed by Professor Andrew Watterson, head of the Occupational and Environmental Health Research Group at Stirling University. “This research indicates the potential risks associated with the use of this insecticide,” he said.
He urged the UK government to learn from the precautionary bans in France and elsewhere. “This merits serious scrutiny in a UK context,” he added. “Controls on applications should be considered.”
Environmental groups ranging from the Soil Association, which certifies organic food, to Buglife, which campaigns to protect insects, are also demanding a ban. Buglife wrote to the UK government last September, but is still awaiting a reply.
“This new information adds to the growing body of evidence that neonicotinoid pesticides are very harmful,” said Buglife’s Vicky Kindemba. “We hope it will strengthen our call to suspend them.”
Beekeepers, meanwhile, are furious. Graham White, an environmental author who keeps bees in the Scottish Borders pointed out that neonicotinoids were revolutionary because they were put inside seeds, and perfused the whole plant.
“Any insect that feeds on the crop dies. Any bee or butterfly that collects pollen or nectar from the crop is poisoned. Even worse, every plant you buy in any garden centre is laced with the toxin.”
Mr White added: “We are witnessing an ecological collapse in all the wildlife that used to live in fields, hedgerows, ponds and streams. All the common species we knew as children are being wiped from the face of the countryside.”
The pesticides industry, however, takes a different view. “A ban on the use of highly effective and specific neonicotinoid seed treatments will have no demonstrable benefits for bee health in the UK,” said Dominic Dyer, the chief executive of the Crop Protection Association, which represents pesticide companies.
“By contrast it could result in unnecessary crop failure due to pest attack or a significant increase in the use of other broad spectrum insecticides.”
One of the main manufacturers, the German company Bayer, dismissed the fears expressed by Dr Tennekes as “unfounded”. Studies had shown that there was “no correlation” between exposure of bees to the insecticide and increased colony mortality, insisted the company.
According to the UK government, the new study highlights the need for more data on the long term risks to bee health. “We will keep this area under review and will not hesitate to act if there is any evidence of an unacceptable risk to bees,” said a spokesperson for the Department for Environment, Food and Rural Affairs in London.
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