US use of pesticides falls, but harms pollinators more

U.S. farmers use smaller amounts of better-targeted pesticides, but it harms pollinators, aquatic insects and some plants much more than decades ago, a new study shows.

Toxicity levels have more than doubled since 2005 for important species, including honeybees, flying flowers and buttercups, as the country switched to a new generation of pesticides. But the dangerous chemical levels of birds and mammals have dropped simultaneously, according to an article in Thursday’s journal Science.

“The bottom line is that these pesticides, which were previously believed to be relatively benign and so short-lived that they will not damage ecosystems, are anything but,” said Dr. Lynn Goldman, a former administrator of the U.S. Environmental Protection Agency for Toxic Substances, said was not part of the study and is now dean of George Washington University’s School of Public Health

German scientists have studied 381 pesticides used in the United States between 1992 and 2016 and EPA data calculating toxic dose effects for eight species of animals and plants combined with US Geological Survey data on how many chemicals are used annually for dozens of farms is. crops. The scientists calculated a new measurement they call total applied toxicity for the eight groups of species and trends over time.

“Often politicians, media, scientists just talk about quantities. They always argue ‘OK, the amount of pesticides we use is reduced to make it better’ and that’s not necessarily true,” said lead author Ralf Schulz, a professor in environmental issues, said. sciences at the University of Kolenz-Landau. “This is sometimes true, but not always,”

Schulz says the industry continues to develop new pesticides and “very often these new compounds are more toxic.” It contains neonicotinoids, which have been linked to one of the many causes of the declining number of honeybees.

The newer pesticides are more targeted at spineless animals to save birds and mammals, but that means insects like poisons are poisoned, Schulz said.

The same is true for some terrestrial plants and for invertebrates in the water, including dragonflies and multi-flies, which eat birds and mammals, he said, adding that future studies should look at the damage higher in the food chain.

Chris Novak, president of the pesticide group CropLife America, said in an email that ‘it is critical to note that the study found that over the past few decades large reductions in acute toxicity to humans and mammals have been achieved. . ‘

Novak noted that pesticides are undergoing extensive studies and “only one in 10,000 discoveries make the 11-year journey from the laboratory to the market.”

It is not surprising that newer generations of pesticides are generally more harmful to insects, which for many reasons are undergoing a tremendous decline, says David Wagner, entomologist at the University of Connecticut, who was not part of the study. But Wagner said this latest research does not contain the necessary information to show that pesticides are the biggest cause of insect decline.

© 2021 The Associated Press. All rights reserved. This material may not be published, broadcast, rewritten or redistributed without permission.