Previous research has suggested that Radio-frequency electromagnetic radiation (RF-EMR) emitted by the devices can have a detrimental effect on male fertility. Most of the global adult population own mobile phones, and around 14% of couples in high and middle income countries have difficulty conceiving.

A team led by Dr Fiona Mathews, of Biosciences at the University of Exeter, conducted a systematic review of the findings from ten studies, including 1,492 samples, with the aim of clarifying the potential role of this environmental exposure.

Participants in the studies were from fertility clinics and research centres, and sperm quality was measured in three different ways: motility (the ability of sperm to move properly towards an egg), viability (the proportion of sperm that were alive) and concentration (the number of sperm per unit of semen).

In control groups, 50-85% of sperm have normal movement. The researchers found this proportion fell by an average of 8 percentage points when there was exposure to mobile phones. Similar effects were seen for sperm viability. The effects on sperm concentration were less clear.

Dr Mathews said: "Given the enormous scale of mobile phone use around the world, the potential role of this environmental exposure needs to be clarified. This study strongly suggests that being exposed to radio-frequency electromagnetic radiation from carrying mobiles in trouser pockets negatively affects sperm quality. This could be particularly important for men already on the borderline of infertility, and further research is required to determine the full clinical implications for the general population."

The results were consistent across in vitro studies conducted under controlled conditions and observational in vivo studies conducted on men in the general population.

"Effect of mobile telephones on sperm quality: a systematic review and meta-analysis" by Fiona Mathews et al is published today in the journal Environment International.

Story Source:

The above story is based on materials provided by University of Exeter. Note: Materials may be edited for content and length.

The results, based on studies in mice, are published in the March 15 issue ofScientific Reports, a Nature publication.

"This is the first experimental evidence that fetal exposure to radiofrequency radiation from cellular telephones does in fact affect adult behavior," said senior author Dr. Hugh S. Taylor, professor and chief of the Division of Reproductive Endocrinology and Infertility in the Department of Obstetrics, Gynecology & Reproductive Sciences.

Taylor and co-authors exposed pregnant mice to radiation from a muted and silenced cell phone positioned above the cage and placed on an active phone call for the duration of the trial. A control group of mice was kept under the same conditions but with the phone deactivated.

The team measured the brain electrical activity of adult mice that were exposed to radiation as fetuses, and conducted a battery of psychological and behavioral tests. They found that the mice that were exposed to radiation tended to be more hyperactive and had reduced memory capacity. Taylor attributed the behavioral changes to an effect during pregnancy on the development of neurons in the prefrontal cortex region of the brain.

Attention deficit hyperactivity disorder (ADHD), is a developmental disorder associated with neuropathology localized primarily to the same brain region, and is characterized by inattention and hyperactivity.

"We have shown that behavioral problems in mice that resemble ADHD are caused by cell phone exposure in the womb," said Taylor. "The rise in behavioral disorders in human children may be in part due to fetal cellular telephone irradiation exposure."

Taylor said that further research is needed in humans to better understand the mechanisms behind these findings and to establish safe exposure limits during pregnancy. Nevertheless, he said, limiting exposure of the fetus seems warranted.

First author Tamir Aldad added that rodent pregnancies last only 19 days and offspring are born with a less-developed brain than human babies, so further research is needed to determine if the potential risks of exposure to radiation during human pregnancy are similar.

"Cell phones were used in this study to mimic potential human exposure but future research will instead use standard electromagnetic field generators to more precisely define the level of exposure," said Aldad.

Other Yale authors on the study include Geliang Gan and Xiao-Bing Gao.

The study was funded by grants from the Eunice Kennedy Shriver National Institute of Child Health & Human Development, and Environment and Human Health, Inc.

Story Source:

The above story is based on materials provided by Yale University. The original article was written by Karen N. Peart. Note: Materials may be edited for content and length.

Journal Reference:

1. Tamir S. Aldad, Geliang Gan, Xiao-Bing Gao, Hugh S. Taylor. Fetal Radiofrequency Radiation Exposure From 800-1900 Mhz-Rated Cellular Telephones Affects Neurodevelopment and Behavior in Mice. Scientific Reports, 2012; 2 DOI: 10.1038/srep00312