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, trace amounts of the neonicotinoids were still present after passing the water through the facilities’ carbon filtration systems. Granted, the amounts present ranged from 0.24 to 57.3 nanograms per liter, which Gizmodo describes as “like a single drop of water plopped into 20 Olympic-size swimming pools.”
The amount is obviously incredibly small, but unfortunately scientists have no idea whether the residue that remains in drinking water could potentially impact human health. The Environmental Protection Agency has set no regulatory limits on the use of these substances, saying that previous studies have shown they have only low rates of adverse health effects for humans. There’s a catch, though – those older studies only looked at brief exposure to high concentrations of neonicotinoids. It’s still unknown whether low-level chronic exposure could result in long-term health problems.
Ideally, more research would be done to learn more about the effect these chemicals have on human health. But with Donald Trump and his cabinet attempting to loosen regulations on industries that pollute the environment and hobbling critical environmental research, it may be a few years before we know for certain whether low levels of neonicotinoids are harmful or not.