How 'the new DDT' wreaks havoc on the bottom of the food chain

by Stephen Leahy | 26 Jun 2014

The same insecticide nerve poison that is contributing to the shocking declines in bees and other pollinators is also behind the sharp declines in many other insect species, along with insect-eating birds and bats. Even important creatures like earthworms, which keep our soils healthy, are being damaged by systemic insecticides called neonicotinoids (neonics) and fipronil, a new four-year international meta-analysis has found. 

“It’s the new DDT but different,” said Ole Hendrickson, a former scientist at Environment Canada and member of the Task Force on Systemic Pesticides that complete the Worldwide Integrated Assessment (WIA) analysis. It's the first examination of all the science on the topicmore than 800 studies. The task force is compromised of 50 independent scientists from all over the world who spent the last four years trying to figure out why so many bees, butterflies, and other insects are disappearing. 

“Instead of wiping out the top of the food chain, killing hawks and eagles as DDT did, neonics are wiping out the bottom of the food chain,” Hendrickson told me. “Harvard biologist E.O. Wilson once said if we wipe out the world’s insects, we will soon follow them to extinction.”  

Over the past 15 years, neonics have become the most widely used insecticides on the planet. They’re everywhere: in homes, gardens, farms, lakes, rivers and forests. The six main types of neonics in use are very, very good at destroying the nerve cells of anything that ingests them.

“Neonics are 5,000 to 10,000 times more toxic than DDT,” said Jean-Marc Bonmatin of The National Centre for Scientific Research in France. 

Many corn, soy, and wheat seeds planted today are coated with neonics. If a bird eats a seed or two, they die. Clouds of toxic dust that are stirred up during planting are also dangerous to birds and insects in the vicinity. As the crops grow, they incorporate the neonic into their tissue, making them poisonous to any insect that nibbles on them. Pollen, nectar, sap and even dead leaves contain neonics. So does the soil, and because neonics readily mix with water, they're contaminating streams, ponds, rivers, and possibly coastal zones, the analysis found. 

Neonics can last and build up in soil and water for more than year. “Even at extraordinarily low levels neonics have impacts on many species,” said Bonmatin, the lead author of the WIA analysis, which will be published as a series of articles in the peer-reviewed journal Environment Science and Pollution Research.

At non-lethal levels, exposure to these nerve poisons can screw up nervous systems. The documented impacts include impaired sense of smell or memory; reduced fertility; altered feeding behaviour and reduced food intake; difficulty in flight and increased susceptibility to disease and altered tunnelling behaviour in earthworms. Hardest hit by all this is not bees, contrary to popular belief, but worms, and other invertebrates that live in the soil, the study found. 

"These are the organisms that cycle nutrients and keep soil fertile. Without them farmers will have to add more chemical fertilizer," Bonmatin told me in an interview.

He said these toxic pesticides aren't even necessary—they're just "convenient." This is nothing like a farmer spraying when there is a pest problem; neonics are in the plant 24/7, from seed to harvest. "At least 90 percent of the time the neonics aren't even needed, according to our studies," he said. There are many effective, pre-existing alternatives for dealing with insect pests, including crop rotation, the analysis also shows. 

Now there is some emerging evidence of neonics' potential impacts on human health. 

"The insects are showing us to be very careful with neonics," Bonmatin said. “They're dangerous and probably should be banned." The official position of the Task Force is to ask governments to restrict their use.

Europe already placed a two-year moratorium on use of some neonics in April 2013 because of the impact on bees, and on June 20, just four days before the release of the WIA analysis, the Obama administration told the Environmental Protection Agency (EPA) to review the impacts of neonics on bees and other pollinators. The EPA has 180 days to report. 

"There is no question that neonics are behind colony collapse disorder," said Chensheng (Alex) Lu, associate professor of environmental exposure biology at Harvard School of Public Health. Lu recently replicated an early study showing low doses of neonics result in the loss of honey bee colonies known as colony collapse disorder (CCD).

The new study showed that only half of the colonies survived the winter when healthy bees were exposed to neonics. Lu believes neonics impair the bee's neurological functions. "The health situation of bees in the US is dire and getting worse," he said.   

The EPA is "misreporting" what's happening to bees by claiming CCD losses have improved dramatically since 2008, Lu said. According to him, Ohio and nearby states lost up to 90% of their colonies last winter while the EPA reported losses of only 30% nationwide. The biggest losses of bees are in the midwest, where the highest levels of neonics are. 

Lu criticised the EPA's strategy of spending millions on improving bee habitat in the midwest, which he said was pushed by the pesticide lobby, and also wondered why the USDA, the ultimate authority on the use of neonics, has been silent on a major study by the American Bird Conservancy in 2013 that clearly documented “massive impacts on American songbirds.” That report criticized the EPA for underestimating the risk and then failing to act when impacts were documented. 

"This is a not a controversial problem," Lu said. "We know what to do."



Author: Stephen Leahy
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