Men who are trying to have children should consider limiting their cellphone use, researchers warn.
It appears that while cell phone use appears actually to increase the level of testosterone circulating in the body, it may also lead to low sperm quality and a decrease in fertility.
"Our findings were a little bit puzzling," says Rany Shamloul, a postdoctoral fellow in the Department of Pharmacology and Toxicology at Queens University, Belfast.
"We were expecting to find different results, but the results we did find suggest that there could be some intriguing mechanisms at work."
The team discovered that men who regularly used a cellphone had higher levels of circulating testosterone - but they also had lower levels of luteinizing hormone (LH), an important reproductive hormone that is secreted by the pituitary gland in the brain.
They're still scratching their heads over the findings, but hypothesize that the electromagnetic waves emitted by cellphones may have a dual action on male hormone levels and fertility.
The radiation may increase the number of cells in the testes that produce testosterone; however, by lowering the levels of LH excreted by the pituitary gland, it may also block the conversion of this basic circulating type of testosterone to the more active, potent form that's associated with sperm production and fertility.
They say more in-depth research is needed to determine the exact ways in which cellphone radiation affects male fertility.