A class of insecticides called neonicotinoids, which are used on a lot of big corn and soybean fields, have been getting a pretty bad rap lately.
Researchers have implicated these chemicals, which are similar to nicotine, as a contributor to the alarming decline of bee colonies. That led the European Union to place a moratorium on their use, and environmentalists want the U.S. to do the same.
In a study published July 24, researchers at the U.S. Geological Survey found that these chemicals are also leaching into streams and rivers in the Midwest — including the Missouri and Mississippi rivers. And that may be bad news for aquatic life in the region, the scientists say.
"We did the study because the use of the neonicotinoids has been increasing dramatically, especially in the Midwest," says Kathryn Kuivila, an environmental organic chemist with the USGS.
And since these chemicals are highly water soluble, it made sense to investigate whether they were present in the region's streams and rivers, Kuivila tells The Salt.
These pesticides aren't sprayed on. Instead, they're used to coat the seeds of many agricultural crops. But they still end up in the soil and then in the water that runs off farms.
Runoff transports the chemicals from the field to streams and rivers, and since they don't break down easily in the environment they can stick around in these bodies of water for long periods of time, the USGS study notes. And while they're not especially toxic to humans, they can harm a wide variety of insects. At certain concentrations, they can hurt other animals as well.
The Salt
Studies Show Why Insecticides Are Bad News For Bees