(NaturalNews) Cell phone use in men is associated with lower sperm quality, according to a study led by researchers from the University of Exeter and published in the journal Environment International on June 9.
The researchers believe that the effect probably comes from men carrying their mobile phones in their pockets, causing irradiation to the testes.
"This study strongly suggests that being exposed to radio-frequency electromagnetic radiation from carrying mobiles in trouser pockets negatively affects sperm quality," lead researcher Fiona Mathews said. "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 researchers reviewed the results of ten separate studies on the connection between exposure to the radio-frequency electromagnetic radiation (RF-EMR) from cellular phones and three separate measures of sperm quality: motility, viability and concentration.
Motility refers to sperm's ability to move properly; viability refers to the proportion of sperm cells that were still alive, and concentration refers to the number of sperm cells in a given volume of semen.
The studies included a total of 1,492 men recruited from fertility clinics or fertility research centers. The researchers found that men with more exposure to cellular phones had roughly 8 percent less sperm motility and viability than men with less exposure. The results on sperm concentration were unclear. The risk increased if phones were kept in pockets longer, and with phones that emitted more radiation.
The results were consistent between two separate types of study: in vitro studies, consisting of controlled conditions in a laboratory; and observational (in vivo) studies conducted on the general population.
Emerging picture of cell phone risk
Although the study was not designed to explain why cell phones might damage sperm quality, prior studies have suggested that the magnetic fields generated by mobile phones may promote the formation of unstable oxygen compounds (free radicals) in the body, which then damage cells and DNA, including that of sperm. Other studies have suggested that the magnetic fields generated by cell phones might cause temperature increases of up to 2.3°C (4.1°F) on the skin, which may be enough to interfere with healthy sperm production.
"Given the enormous scale of mobile phone use around the world, the potential role of this environmental exposure needs to be clarified," said Dr. Fiona Matthews, who led the study.
The majority of adults worldwide now own cell phones. At the same time, fertility problems in high- and middle-income countries have climbed in recent years to 14 percent.
"The studies are coming out with a consistent message that sperm motility declines with exposure to mobile telephones and similarly proportion which are alive, it's about an eight percentage point fall," Dr. Matthews said.
"[I]f you already know you have a potential fertility issue then it might be an additional thing to consider - just as you might change your diet - you might want to change where you keep your phone."
The study authors also warn that other wireless devices, including laptops, tablets and anything with Wi-Fi, probably have similar effects on sperm. Evidence now suggests that the cumulative radiation from all these devices is having an even greater impact, they said.
"For example, recent evidence found wifi from laptops also negatively affected sperm quality," the researchers wrote. "A better understanding of the collective influence of environmental factors on sperm quality and subsequent fertility, will help improve treatment, advice and support for individuals seeking fertility treatment."
Research has also linked mobile phone use to other health problems, including brain tumors, leading several countries (such as France, Israel, Finland and India) to institute policies designed to reduce citizen exposure.