Exposure to aluminum could cause men's sperm count to fall significantly.

Researchers used fluorescence microscopy via an aluminum-specific stain to look for aluminum levels in semen and even individual sperm, Keele University in England reported.

The research team, 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 aluminum exposure in the semen of 62 donors at the French clinic.

"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," Exley said.

"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," he continued.

In each patient the semen was analyzed following World Health Organization (WHO) guidelines. Along with the graphite furnace atomic absorption spectrometry method a cytological analysis using an aluminum-specific fluor, lumogallion, was also performed.

All 62 donors were found to have relatively high aluminum levels of about 339 parts per billion and a few of the samples were as high as 500 ppb. The researchers observed a statistically significant inverse relationship between aluminum levels in semen and sperm count. Higher in aluminum was is believed to result in lower sperm count. There was not found to be a significant difference in semen parameters.

"This study provided unequivocal evidence of high concentrations of aluminum in human semen and suggested possible implications for spermatogenesis and sperm count," the researchers wrote in the study abstract.