Scientists from the North Carolina State University in the US studied the level of contamination of fresh water and stated that present chemicals may change sex.
The researchers have evidenced such gender changes only in fish so far.
Because of Xenoestrogens presence in male fish, they lost not only reproduction function, but also acquired hermaphroditism.
Xenoestrogens, that function as hormone disrupters, have become ubiquitous in the environment. They come from man-made things, including pollution, pesticides, and plastics.
Black bass and sunfish, commonly found in the fresh waters of North Carolina, were studied by the researchers, who had tested 20 streams and rivers containing xenoestrogens during the 2012 spawning season and detected 135 types of them. They found that 60% of the black bass tested had eggs in their testes, as did 10% of the sunfish they evaluated.
If high estrogen goes on long enough, prostate and testicular cancer can develop in humans. Another outcome of xenoestrogens may be breast cancer.