
We’ve known that neonicotinoid insecticides are bad news for bee populations for several years now, but one thing we don’t know about these pesticides is how they impact human health. A new study from the US Geological Survey and the University of Iowa reveals how terrifying that question could be, revealing minute traces of neonicotinoid chemicals are present in at least some drinking water in the US.

In the study, published in the journal Environmental Science and Technology Letters, researchers took samples from two water treatment plants in Iowa. Though many might assume waste treatment plants would be able to remove pesticides from drinking water,…