Pesticides used in agriculture have been linked to some frog deformities in Minnesota, according to two new studies published in the journal Environmental Toxicology and Chemistry. A combination of chemicals in Minnesota ponds appears to be causing malformations of frogs’ limbs, eyes, mouths, and other parts. Doug Fort, a coauthor of one of the studies, said several of the chemicals suspected of causing deformities appear to affect the thyroid, which is the primary gland responsible for growth, maturation, and development in most animals. The researchers couldn’t say whether the pesticides might also adversely affect humans and other animals.