Endocrine disruptive substances are found in food and a variety of items such as clothing, sunscreen, shower gels, pharmaceuticals, plastic bottles and children's toys. There is a longstanding discussion as to how these substances may affect human fertility.

The research team led by Dr. Timo Strünker from the Center of Advanced European Studies and Research in Bonn and Prof. Niels E. Skakkebaek from the Department of Growth and Reproduction at Rigshospitalet in Copenhagen, Denmark,  observed in vitro that hormonally active substances affected the sperms’ swimming behaviour by opening the so-called CatSper ion channels. These calcium channels control the swimming behaviour and normally trigger the release of digestive enzymes that enable a sperm cell to penetrate the ovum’s membrane. Opening the channel triggers this behaviour prematurely, before the sperm reaches the ovum. Endocrine disruptors also make the sperm cells less sensitive to progesterone and prostaglandins.

Source (in German):
http://www.innovations-report.com/html/reports/medicine-health/endocrine-disruptors-impair-human-sperm-function.html