Hundreds to thousands endocrine-disrupting chemicals found in toothpaste, soap and plastic toys could be behind drop in male fertility, as revealed from the findings of a German- Danish team of researchers from the Center of Advanced European Studies and Research.

Niels E. Skakkebaek, professor and leader of the Danish team said that for the first time, they showed a direct link between exposure to endocrine disrupting chemicals from industrial products and adverse effects on human sperm function.

The scientists looked at the impact of these chemicals on the CatSper ion channel, a calcium channel that controlled sperm motility.

The scientists showed that when endocrine disruptors were applied at concentrations measured in body fluids, it directly opened CatSper and, thereby, increased the calcium levels in sperm, changed their swimming behavior, and triggered the release of digestive enzymes that helped the sperm to break through the egg coat.

The study indicated that endocrine disruptors might disturb the precisely coordinated sequence of events underlying fertilization in several ways, i.e. the chemicals might evoke changes in swimming behavior at the wrong time and wrong place, hinder navigation of sperm towards the egg, and also might hamper the penetration into the protective egg coat.