Do you know the expression "canary in a coal mine?" Miners used to use canaries to warn them when dangerous gases were building up in the mines. Canaries are sensitive to methane and carbon monoxide, and will die at lower levels than it would take to kill a human. If the canary stopped singing (i.e. if it died), it was time to get out of the coal mine, a.s.a.p.
Scientists have been saying for years that certain animals are starting to exhibit "intersex characteristics" in far greater numbers than should be found naturally. Intersex means that the animals exhibit characteristics of both male and female genders. In a common example, a male fish will be found with immature eggs in their testes. Intersex is thought to be caused by endocrine disruptors, chemicals which interfere with the hormonal system. Some species seem to be more vulnerable than others, and some locales seem to be more affected than others. A well-known problem area is the Potomac River, near Washington DC, where a recent survey found 80% of fish exhibiting intersex characteristics. 80%, people. In another study, all the fish, whether intersex or not, were found to be contaminated with at least one endocrine disruptor, of the type typically found in personal care products such as antimicrobial products and artificial fragrances.
Studies have been published, articles have been written, yet the flow of chemicals into our waterways (and our bodies) continues unabated. The Potomac Conservancy is trying to get people to pay attention. They've launched a campaign called FishMystery. You can sign a petition calling for more attention to and investment in this problem. You can read about ways to minimize your exposure to endocrine disruption. You can read studies and press releases. But they really shouldn't call it a mystery. It's incredibly obvious where the chemicals are coming from, and what the implications are going to be if we don't get the hell out of the mine.
Article in The Guardian re intersex fish
A related post I wrote a year ago