Having a lush, dandelion-free lawn may come at an unexpected price. According to a new report, minuscule amounts of over-the-counter weed killers impair reproduction in mice and therefore might also affect other animals, people included.
Previous studies have assessed the toxicity of high doses of single herbicide ingredients, but they haven't tested the chemical cocktails typical of commercial formulations, says toxicologist Warren Porter of the University of Wisconsin–Madison.
He and his colleagues measured the toxicity of an unnamed brand of weed-and-feed mix. It included the herbicides 2,4-D, mecoprop, and dicamba—one or more of which is in each of 1,500 commercial weed-killing formulations. Though herbicides target plants, says Porter, many attack basic biological functions common to both plants and animals.