The discovery of malformed frogs in the Minnesota River watershed in the 1990s touched off field and lab research on endocrine disrupters that is continuing to yield findings.
Minnesota, the state that made national headlines with the discovery of malformed frogs in the 1990s, has found endocrine disrupting chemicals and traces of pharmaceuticals even in some of its most remote and otherwise cleanest waters. Armed with substantial state funding, the Minnesota Pollution Control Agency (MPCA) has released a new report and is now continuing field work to determine the aquatic range of endocrine disrupting chemicals that can mimic hormones and cause changes to the reproductive system or development of organisms.
The new study found the hormones androstenedione in 64 percent of sampled lakes and 50 percent of sampled rivers, estrone in 55 percent of the lakes and 75 percent of the rivers, and 17β-estradiol in 55 percent of the lakes and 38 percent of the rivers. “These may be of human origin, naturally occurring, or both,” MPCA observed. Bisphenol-A was found in 45 percent of the sampled lakes and 38 percent of sampled rivers.