A team of international researchers has found that cell phone use may have negative effects on the fertility of men.

Rany Shamloul, study leader and a postdoctoral fellow in the Department of Pharmacology and Toxicology at Queen's University, along with a team of U.S. and Austrian researchers, have found that male cell phone users have lower quality sperm than those who do not have cell phones.

Shamloul and his team conducted the study between 1993 and 2007 at an Austrian infertility clinic, where the sperm of over 2,000 men had been collected and examined. Men were asked if they owned and used cell phones at the time of collection, and those who used one on a daily basis were labeled cell phone users. 

After studying the collected sperm and cell phone users and non-users, the researchers found that men who regularly used cell phones had higher levels of circulating testosterone, but lower levels of luteinizing hormone, which is a key reproductive hormone that secretes by the pituitary.

The researchers' theory is that the electromagnetic waves that cell phones emit increase the number of testosterone-producing cells, but also lower levels of luteinizing hormone. This, in turn, may negatively impact fertility. 

But at this point, these results are not conclusive. The researchers need more time and research to determine if the cell phone use is really what is causing the low quality sperm, or if it's something else. 

Whether cell phone use is the culprit or not, this is an important first step to more rigorous studies that research the link between male infertility and cell phone electromagnetic waves.