Researchers say there’s a new threat to Iowa’s soil and groundwater. Scores of pollutants like arsenic, lead and mercury, are regulated by the government to keep the water and air clean. But unregulated chemicals, like antibiotics and hormones, are showing up in the environment and we don’t yet understand their effects.

Joel Coats, an entomology and toxicology professor from Iowa State University, studies so-called “emerging contaminants” related to agriculture — in particular, how long antibiotics stay in the environment and how they affect insects, fish and other organisms.

Coats says lots of people are concerned about the subject. He says there are lots of examples of materials occurring in the waters, but we don’t know yet really how significant that is. Coats says with time, animals may develop infections from antibiotic-resistant bacteria from overuse of veterinary antibiotics that are often fed routinely to livestock.

Dan Snow is Director of the Water Sciences Laboratory at the University of Nebraska-Lincoln. Snow says traces of steroids, hormones, pesticides, and antibiotics used in livestock have been found in the environment.

Snow says many of these emerging contaminants aren’t really new. Snow says many of the contaminants have always been around, as farmers have used antibiotics since the fifties in livestock production. But he says we always haven’t had a good way to measure those compounds, or to measure the effects of those compounds on the environment. Snow says scientists now have better tools to measure such chemicals in soil and water and understand their effects.