The world is full of endocrine disruptors. Chemicals that mimic natural hormones in the body are found in a host of products from food packaging to toothpaste to toys. Now researchers in Denmark and Germany have found that many of them—one-third of the 96 they tested—disrupt the way sperm function, affecting their swimming and navigational skills, and thus their ability to fertilize an egg.
Apparently the chemicals lead to abnormally high calcium levels in the sperm, adversely affecting their swimming and causing them to prematurely release enzymes needed to break through the egg's outer coating.
Furthermore, endocrine disrupters in the female reproductive tract may swamp the hormonal signal that sperm use to find the egg. Hormones produced by the egg tell sperm where to find it, but if other chemicals mimic those hormones, the sperm may be led astray.
This sounds like bad news, but is it? One wonders. The seven billion people on Earth are relentlessly polluting the planet while simultaneously exhausting its resources, and by mid-century we are predicted to grow to 10 billion. Curbing our fecundity may not be a bad thing. How ironic if we are being emasculated by our own excesses.