Tuesday, June 24, 2014

Silent Spring - the Sequel

The world’s most widely used insecticides have contaminated the environment across the planet so pervasively that global food production is at risk, according to a comprehensive scientific assessment of the chemicals’ impacts. Billions of dollars’ worth of the potent and long-lasting neurotoxins are sold every year but regulations have failed to prevent the poisoning of almost all habitats, the international team of scientists concluded in the most detailed study yet. As a result, they say, creatures essential to global food production – from bees to earthworms – are likely to be suffering grave harm and the chemicals must be phased out.

Neonicotinoids, a class of insecticides, are applied routinely rather than in response to pest attacks but the scientists highlight the “striking” lack of evidence that this leads to increased crop yields.  These chemicals are different from other pesticides because, instead of being sprayed over crops, they are usually used to treat seeds. This means they are taken up by every part of the growing plant, including roots, leaves, pollen and nectar, providing multiple ways for other creatures to be exposed. The toxicity of neonicotinoids has only been established for very few of the species known to be exposed. For example, just four of the 25,000 known species of bee have been assessed. There is virtually no data on effects on reptiles or mammals.

“The evidence is very clear. We are witnessing a threat to the productivity of our natural and farmed environment equivalent to that posed by organophosphates or DDT,” said Jean-Marc Bonmatin, of the National Centre for Scientific Research (CNRS) in France, one of the 29 international researchers who conducted the four-year assessment. “Far from protecting food production, the use of neonicotinoid insecticides is threatening the very infrastructure which enables it.” He said the chemicals imperilled food supplies by harming bees and other pollinators, which fertilise about three-quarters of the world’s crops, and the organisms that create the healthy soils which the world’s food requires in order to grow.

“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.

Professor Dave Goulson, at the University of Sussex, another member of the team, said: “It is astonishing we have learned so little. After Silent Spring revealed the unfortunate side-effects of those chemicals, there was a big backlash. But we seem to have gone back to exactly what we were doing in the 1950s. It is just history repeating itself. The pervasive nature of these chemicals mean they are found everywhere now. If all our soils are toxic, that should really worry us, as soil is crucial to food production."

Full story here

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