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Does radiofrequency radiation emitted from mobile phones have an effect on sperm cells?

 

In recent years animal models and human semen samples were studied in order to investigate if exposure to radiofrequency (RF) radiation, specifically, radiation emitted by mobile phones, causes a decrease in sperm cell quality or damage to sperm cells and subsequently leads to decreased fertility.

 

 

A mobile phone in the front trouser pocketA mobile phone in the front trouser pocket

 

Results of studies that examined the effect of non-ionizing radiation in the radiofrequency (RF) range on sperm quality parameters are equivocal. In some studies, exposure to radiation emitted by mobile phones did not seem to have an effect on sperm cell quality, while other studies reported an effect on some sperm quality parameters such as motility, vitality, morphology, and DNA fragmentation.

Considering studies that demonstrated damage to sperm cells or decreased sperm quality following exposure to RF radiation, and based on the precautionary principle, educated use of mobile phones is recommended: not to carry mobile phones close to the body, in the trouser pocket, or to place them in the vicinity of the testes.

 

 

According to the World Health Organization, infertility is the failure to achieve a clinical pregnancy after 12 months or more of regular unprotected sexual intercourse.

 

In recent years there have been various reports on decreased fertility in humans, and specifically on decreased sperm cell quality. Some people believe that the reported decreased fertility results from increased use and exposure to technologies that emit non-ionizing radiation, for example, mobile phones, wireless routers (Wi-Fi), cellular base stations, etc. Is this presumption correct? In the following article we present a summary of the studies that investigated the relationship between exposure to radiofrequency (RF) radiation and sperm cell quality. 

 

What are the factors that affect fertility in men?

Many factors may affect fertility in men. The main hypothesis is that environmental or lifestyle factors may cause damage to the testes at the time around birth or during puberty. Additionally, exposure to heat, ionizing radiation or to estrogens or anabolic steroids may harm the testes of adult males. The impact of smoking, drinking alcoholic beverages and physical inactivity on sperm quality is not clear yet.

 

In recent years research was performed in order to investigate if exposure to radiofrequency (RF) radiation, and specifically to RF radiation emitted by mobile phones, causes a reduction in sperm cell quality or sperm cell damage, subsequently reducing fertility.

 

How is sperm cell quality evaluated? 

According to The World Health Organization, the reference (i.e., normal) values of semen are:

  • Semen Volume: 6-1.5 milliliters
  • pH: 9-7
  • Sperm concentration: 15 million per milliliter
  • Motility: at least 45% of sperm cells should have progressive motility
  • Morphology (shape): the sperm cell's head, midpiece and tail are examined. This parameter is considered normal when 4-14% of sperm cells have normal morphology. 

Illustration: sperm cells

Illustration: sperm cells

 

Notably, sperm cell quality is determined by all of the above parameters.   

 

 

Research in humans on the effects of exposure to radiofrequency radiation on male fertility

This subject can be scientifically investigated in several ways:

  1. Exposure of sperm cell samples from healthy volunteers to non-ionizing radiation under laboratory conditions. In this type of study, sperm cell samples are exposed to non-ionizing radiation. Various sperm cell parameters are then compared between cells that were exposed to non-ionizing radiation and cells that were not exposed (in vitro study).
  2. Investigation of the association between the level of exposure to non-ionizing radiation of a group of volunteers and the semen quality of the same volunteers (cross-sectional study)
  3. Investigation of the association between the level of exposure to non-ionizing radiation of a specific population and the fertility rates in the same population (ecological study)

 

Most of the studies conducted in the research area were cross-sectional or in vitro studies.

 

Results of in vitro studies

Results of these studies are equivocal. In some of these studies no effect on semen quality was observed after exposure to radiation emitted by mobile phones. Other studies, have reported a change in some sperm parameters, including motility, vitality, morphology, or sperm cell DNA intactness after exposure to radiation emitted by mobile phones.

 

Illustration: Fertilization of egg in vitro

Illustration: Fertilization of egg in vitro

 

 

Meta-analyses that were based on the results of these studies, could not determine if RF radiation has an effect on semen quality. In a meta-analysis published in 2014, the results of 10 studies that investigated the effect of exposure to radiation from mobile phones in the 850-900 MHz frequency range on human semen samples was examined quantitatively. In these studies the duration of exposure ranged from 5 minutes to 16 hours. Of 9 studies that presented data on sperm motility (a total of 1448 samples), 6 studies showed that RF exposure decreased sperm motility. Of 5 studies that presented data on sperm vitality (816 samples), 4 studies showed decreased motility following exposure. Six studies presented data on sperm concentration (1376 samples) but none of them showed a decrease in sperm concentration after exposure to radiation in these frequency ranges.

 

Notably, there was heterogeneity among the studies evaluated in the meta-analysis. For example, the studies described different RF exposure conditions and different exposure durations. In some of the studies, the population included men who attended fertility clinics; therefore their sperm quality may not have been normal to start with. Such heterogeneity, makes comparing the results of the various studies difficult.

 

Studies in animal models (in vivo studies)

Studies conducted in animal models (rats, mice, rabbits) also could not find an unequivocal answer to the question of whether RF radiation emitted by mobile phones has an effect on sperm cells. Some of the studies have shown that exposure to non-ionizing radiation in the RF range decreased sperm motility, concentration and vitality; while other studies could not prove that this type of radiation has a negative effect on sperm cells. 

Laboratory rats

Laboratory rats

 

Biologic Mechanisms related to the effect of radiofrequency radiation on sperm cells

Several hypotheses were suggested regarding the mechanism by which RF radiation may have an effect on sperm cells.

 

One of the suggested mechanisms relates to the effect of the heat emitted by mobile phones on sperm cells (thermal effect): for normal production of sperm cells, the temperature of the testes should be 2 degrees Celsius lower than the body temperature. Thermal effects may increase the temperature of the testes, because often individuals carry their mobile phones in the front trouser pocket, close to the reproductive organs. Importantly, RF radiation emitted by mobile phones has a negligible heating effect; therefore, the mobile phone is the source of heat, rather than the radiation emitted by it.

 

Several hypotheses were made about the non-thermal effects of RF radiation. For example, it was proposed that radiation may cause oxidative stress due to increased production of free radicals in the cell and a decrease in antioxidative factors. In such a situation, the cells cannot cope with the amount of free radicals, and damage to various cellular molecules, such as DNA or proteins may occur. Consequently there may be an effect on protein function, sex hormones and decreased production of sperm cells.

 

 
   

 

In Summary

Results of studies that examined the effect of non-ionizing radiation in the radiofrequency (RF) range on sperm quality parameters are equivocal. Considering studies that demonstrated damage to sperm cells or decreased sperm quality following exposure to RF, and based on the precautionary principle, educated use of mobile phones is recommended: not to carry mobile phones close to the body, in the trouser pocket, or to place them in vicinity of the testes.

 

   

 

References

 

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