Cell phone use could affect sperm and it may be linked to a decline in fertility, according to recent findings.

The number of hours men use cell phones each day was linked to sperm counts and quality, according to findings announced Monday and presented at the 62nd annual meeting of the American Society for Reproductive Medicine (ASRM). The findings are preliminary and have not been confirmed.

Researchers in Cleveland, Mumbai and New Orleans observed 364 men, who were divided according to cell phone use. Those who did not use cell phones at all had sperm counts of 86 million per milliliter, with 68 percent motility (ability to move) and 40 percent normal shape and form.

Men who used cell phones more than four hours a day had a sperm count of 66 million per milliliter, with 48 percent motility and 21 percent normal shape and form. That is a significant reduction, according to the ASRM.

The World Health Organization states that normal sperm count is at least 20 million per milliliter, with normal at least 50 percent motility and 30 percent normal shape and form.

Researchers believe the effect of cell phones on sperm may be due to electromagnetic radiation or to the heat cell phones generate. They noted that more study is needed to identify the mechanism involved in the reduction of sperm quality due to cell phones.