What does this portend for the health of all creatures—and people?
Some of the refuges sampled, such as John Heinz at Tinicum in Philadelphia and Great Swamp in New Jersey, are close to major East Coast urban centers. Others, including Moosehorn National Wildlife Refuge in Maine and Missisquoi, are more remote—surrounded by forests, farm fields, and small towns.
The researchers found intersex smallmouth bass everywhere they looked. About 85 percent of the males collected in the refuges were intersex.
Mounting evidence suggests that intersex in fish may be the result of exposure to contaminants that encompass a wide range of natural and synthetic chemicals, including pharmaceuticals, pesticides, and personal care products. Some chemicals of concern include estrogens from birth control pills, the plasticizer bisphenol A, and the herbicide atrazine. These chemicals can mimic and in some cases interrupt a body’s normal hormonal processes.
For most of the refuges, there are no identifiable sources—no sewage treatment plant or industrial facility, for example—putting out pollutants that could explain the phenomenon.
“It’s really pretty staggering to be seeing these percentages in areas we would think of as pristine natural areas,”… [emphasis mine]