Human exposure to aluminum may be a significant factor in falling sperm counts and reduced male fertility, new research suggests.
Fluorescence microscopy using an aluminum-specific stain confirmed the presence of aluminum in semen and showed aluminum inside individual sperm.
And the team of scientists, at the universities of Lyon and Saint-Etienne in France and Keele in the UK, found that the higher the aluminum, the lower sperm count.
The research, led by Professor Christopher Exley, a leading authority on human exposure to aluminum at Keele, and Professor Michele Cottier, a specialist in cytology and histology at Saint-Etienne, measured the aluminum content of semen from 62 donors at a French clinic.
Professor Exley said: "There has been a significant decline in male fertility, including sperm count, throughout the developed world over the past several decades and previous research has linked this to environmental factors such as endocrine disruptors.
"Human exposure to aluminum has increased significantly over the same time period and our observation of significant contamination of male semen by aluminum must implicate aluminum as a potential contributor to these changes in reproductive fertility."
The mean aluminum content for all 62 donors was found to be very high at 339 ppb with the aluminum content of semen from several donors being in excess of 500 ppb. A statistically significant inverse relationship was found between the aluminum content of semen and the sperm count. Higher aluminum resulted in a lower sperm count.