The study, conducted by Dr. Ashok Agarwal and in PDF abstract here, reported on the results of 364 men who used cell phones for varying amounts of time each day.
According to Agarwal, men who used their cell phones for four hours a day or more showed the greatest damage to their sperm.
"Those differences are highly significant," Agarwal told eWEEK.
He said that he can only speculate on the reason for the damage, but he said its likely to be the effects of the electromagnetic radiation emitted by the cell phones when they transmit, as they do in use.
"Men that use cell phones had a decreased sperm quality compared with those who dont. Those who use it for long periods of time had a much more profound decrease," he said.
Agarwal said that his study was consistent with previous studies conducted in 2002 and 2005 that found a relationship between exposure to electromagnetic radiation and fertility, as well as with animal studies.
Agarwal said that other studies showed that electromagnetic radiation may cause DNA damage in mice.
The study used only GSM phones operating in frequencies ranging from 800 to 1900 mHz.
According to Agarwal, the Cleveland Clinic is planning a follow-up study that will look at some of the variables that werent considered in this test.
Those variables include the type of phone, the specific frequency and type of transmission.
"There are hundreds of questions that need to be addressed if these findings turn out to be true," Agarwal said.
He mentioned that no one knows whether cell phones have the same effect on women, for example.
He added that there are doubts about his study: "We controlled many of the variables, but not all of them," he said.
Agarwal said that there are a lot of things that researchers dont yet know.
In addition to learning whether women are affected, Agarwal said that the current study is a simple snapshot.
"We did not do a longitudinal study over several months," he said.
In addition, he said that he doesnt know if the damage gets worse with time, or if it gets better if cell phone use is reduced.
Is the damage enough to cause problems for men who want to have children? Perhaps.
"Some of these effects, especially in those who have over four hours of use, put them in a condition thats highly abnormal," Agarwal said.
"I definitely think it will cause problems in men to achieve a pregnancy."
So with all that he has learned, is Agarwal ready to give up his own cell phone?
"Im not ready for that," he said. Adding that he uses his cell phone for an hour or two a day, Agarwal said that hes not changing that now.
"I dont plan to stop," he said. The next study in this series should be out in a year.