Microwaves are part of the wide range of
electromagnetic waves with a frequency range
of 300 MHz-300 GHz (
The Global System for Mobile Communications
(GSM) was established in 1987. The majority of
European and Asian countries, including Iran, use this system. In GSM, the frequencies transmitted
from cell phones to cell phone antennas (base station)
range from 870 to 915 MHz (uplink) whereas
frequencies transmitted from antennas to cell
phones range from 935 to 960 MHz (downlink)
There have been few studies on the effects of cell
phone waves on sperm parameters. Wdowiak et al.
However, the issue in question is that cell phone
waves may cause oxidative stress by enhancing
lipid peroxidation and changing antioxidant
activities in the body (
Antioxidants are molecules responsible for preventing
oxidative homeostasis and coping with
oxidative stress. These molecules prevent the formation
of active oxygen species and inhibit their
functions. Antioxidants are classified into two
groups: enzymatic and non-enzymatic (
Few studies have examined the effects of cell
phone waves on antioxidants. The results of a
study have indicated that cell phone waves increase
lipid peroxidation, decrease the total
concentration of thiols and total antioxidant capacity
of blood plasma, resulting in oxidative
Sperm are sensitive to oxidative stress. The
sperm membrane of mammals is full of unsaturated
fatty acids and sensitive to oxidation. Abnormal
sperm are responsible for the overproduction
of reactive oxygen species (ROS) which result in
oxidative stress and considered to be one of the
causes of male infertility (
Under normal circumstances semen plasma contains
sufficient antioxidant mechanisms and is
able to neutralize the effect of ROS on sperm.
However, if for any reason an imbalance occurs,
the sperm goes through changes that negatively
influence sperm parameters. Age, environmental
factors (e.g., radiation exposure) and nutrition
are factors that affect this change (
Infertility and its related problems are considered
major issues in a couple’s life. The most common
cause of infertility in males is their inability
to produce sufficient normal, active sperm (
This experimental research was carried out on
28 male Wistar rats (200-250 g) in the Fertility
and Infertility Research Center at Kermanshah
University of Medical Sciences. The animals
were purchased from Iran Pasteur Institute and
kept in the animal house of according to recommended
The rats were randomly assigned to 4 groups of 7 rats in each group according to the study design as follows. Group 1 comprised the control group maintained under experimental conditions, without any exposure to simulated cell phone waves. Group 2 animals were exposed to cell phone receiver simulated waves (915 MHz frequency) for 14 days. Group 3 animals were exposed to cell phone receiver simulated waves (915 MHz frequency) for 21 days and group 4 animals were exposed to simulated waves of a cell phone antenna (950 MHz frequency) for 14 days.
In this study, the 915 MHz frequency represented cell phone receiver waves, whereas the 950 MHz represented cell phone antenna waves. Frequencies of 915 or 950 Hz represented cell phone waves.
In order to expose the animals to cell phone-simulated
waves, we constructed a Plexi glass cylinder
that consisted of internal (radius: 15 cm, height:
30 cm) and an internal (radius: 5 cm, height: 30
cm) cylinder. The animals were placed between the
internal and external space during the experiments
and had free access to all areas of the space. The
internal cylinder was intended to prevent the animals
from entering the near field of the monopole
antenna which was vertically installed in the center
of the internal cylinder. The monopole antenna
was used as the simulation device from which cell
phone waves (
The exposure cylinder and radiation chamber
The vertical antenna (monopole) of the cell phone simulation generator was placed in the center of the internal cylinder and the density was measured at 5, 10, and 15 cm from the antenna at a height of 5cm from the floor of exposure cylinder using a portable system (Holaday, USA). The average density in the mentioned distances was 1.60 mw/cm2.
The rats in groups 2 and 3 were exposed to microwaves (915 MHz) as the carrier wave (switch carrier 217 Hz and modulation 200 KHz) for eight hours a day for 14 and 21consecutive days, respectively. Exposure conditions in group 4 were similar to group 2 except that the frequency of radiation waves was 950 MHz.
Animals from all groups were anesthetized
with chloroform at the end of the experiment.
After opening the anterior wall of the thorax,
blood was taken from the heart. The cauda of the
left epididymis was separated and segmented in
HAM’s/F10 (Gibco, UK) that contained 10% fetal
bovine serum which had been maintained at a temperature
of 37˚C and 5% CO2. After 45 minutes,
sperm analysis was performed according to World
Health Organization (WHO) instructions (
Sperm motility was examined according to WHO recommendations and categorized as: a. fast progressive; b. slow progressive; c. non-progressive and d. non-motile in ten microscopic fields. The total sperm that comprised categories a and b were determined as the percentage of motility for each sample.
We performed supra vital staining to identify live sperm. One drop of medium that contained sperm was placed on a slide and mixed with a small drop of eosin B (0.5% in saline). The cover slip was immediately placed on the drop and analyzed at ×400 magnification. In this staining method, the head of a dead sperm, due to deficiency in the membrane, absorbs eosin and turns red. However, live sperm do not absorb color. In each slide, 100 sperm were counted and the percentage of viable sperm reported.
A Neubauer hemocytometer was used to count sperm. One drop of a diluted sample was placed on the slide after which all of the sperm in the central square were counted. Sperm count in 1 ml was calculated.
We used the Papanicolaou staining method to analyze sperm morphology. After staining, sperm in ten microscopic fields were analyzed and classified according to WHO classification as either normal or abnormal (a. deficient in the head, b. deficient in the neck and c. deficient in the cauda). The percentage of sperm with normal morphology was then determined.
After sperm were analyzed they were centrifuged
at a temperature of 4˚C for 15 minutes at
2500 rpm. After separating the supernatant, 1 cc
of phosphate buffer that contained EDTA (
The total antioxidant capacity of the rat sperm
was measured by the ferric reducing ability of
plasma (FRAP) test (Benzie and Strain method)
The samples were incubated at 37˚C for 20 minutes, then centrifuged for 10 minutes at 4˚C and 3000 rpm. Using sampler, 850 μl supernatant was separated from the pellet. Then, the sperm from the remaining sperm pellet that contained 150 μl of buffer liquid were broken by sonication (Labsonic, Germany). During sonication, sample were placed in a salt and ice mixture to avoid decreasing the sample’s antioxidant capacity. After the sperm were broken, the sample was centrifuged (4˚C) again at 8000 rpm. Then, the supernatant was separated from the pellet. At the time of preparing the FRAP solution, it was kept in the freezer (4˚C) and measured immediately after the solution was prepared.
First, we prepared standard solutions at concentrations of 125, 250, 500 and 1000 μM from FeSO4. 7H2O. Then, TPTZ powder (0.0247 g) was dissolved in 7.5 ml HCl (40 mM) to prepare the TPTZ solution after which 7.5 ml of an FeCl3. 6H2O solution (20 mM) and 75 ml of an acetate buffer solution (300 mM, pH=3.6) were added to the TPTZ solution to make the FRAP solution. Chemicals used for the FRAP test were purchased from Merck Company in Germany.
After preparing the FRAP solution, we added 1.5 ml of the solution to 150 μl of distilled water and placed the solution in a water bath (37˚C) equipped with a shaker for five minutes. Then, 50 μl of the experimental or standard group samples were added to the tubes and placed in the same water bath (37˚C) for ten minutes. Immediately the complex absorption rate at a wave length of 593 nm was recorded by spectrophotometer (Jenway 3620D, England). All samples were run in duplicate and measured to enhance analytical accuracy.
The results are written as mean ± SD. Data were analyzed by one-way ANOVA and the Tukey posthoc test using SPSS software version 16. P<0.05 was considered significant.
According to the results, the mean sperm viability
in the control group was 87.64 ± 1.82%.
In the experimental groups the mean sperm viability
was 81.14 ± 2.87% (group 2), 74.71 ±
2.80% (group 3) and 81.00 ± 6.61% (group 4)
which was a significant decrease compared with
the control group. In a comparison between
groups, the increased duration of exposure from
2 to 3 weeks resulted in a significant decrease in
sperm viability (
For sperm count and normal morphology, we
observed no statistical decrease in all exposure
groups compared to the control group (p>0.05). A
comparison of the exposure groups with each other
also showed no statistical difference (p>0.05) in
terms of these two parameters (
The mean sperm total antioxidant capacity in
the control group was 406.35 ± 64.12 μM/60
million sperm and for the experimental groups
it was 297.92 ± 92.76 (group 2), 251.16 ± 48.03
(group 3), and 290.34 ± 71.37 (group 4) μM/60
million sperm. A comparison of the total antioxidant
capacity in the exposure and control
groups indicated that there was a statistically
significant decrease in all three exposure groups
in terms of sperm total antioxidant capacity.
The comparison of exposure groups with each
other showed that the mean sperm total antioxidant
capacity in group 3 decreased compared
with group 2, but this decrease was not statistically
Comparison of the means of sperm parameters in control and exposure groups (one- way ANOVA and Tukey’s test)
|Groups||Sperm count (×106) (mean ± SD)||Sperm viability (%) (mean ± SD)||Sperm motility (%) (mean ± SD)||Normal morphology (%) (mean ± SD)|
|58.56 ± 6.01||87.64 ± 1.82||49.96 ± 4.59||82.06 ± 4.60|
|62.14 ± 8.92||81.14 ± 2.87a||40.91 ± 4.11a||81.78 ± 3.96|
|57.72 ± 8.05||74.71 ± 2.80bc||32.91 ± 4.09bc||79.70 ± 6.61|
|60.19 ± 6.94||81.00 ± 6.61a||41.29 ± 6.41a||83.37 ± 6.04|
Group 1; Control, Group 2; Exposed to simulated cell phone receiver waves (915 MHz) for 14 days, Group 3; Exposed to simulated cell phone receiver waves (915 MHz) for 21 days and Group 4; Exposed to simulated cell phone antenna waves (950 MHz) for 14 days.
a; Compared to control group (p<0.05), b; Compared to control group (p<0.001) and c; Compared to group 2 (p<0.05).
Comparison of the means of total antioxidant capacity of sperm in control and exposure groups (one-way ANOVA and Tukey’s test)
|Groups||Total antioxidant capacity μM/60 million sperm (mean ± SD)||P value (vs. control group)|
|406.35 ± 64.12|
|297.92 ± 92.76||0.044|
|251.16 ± 48.03||0.001|
|290.34 ± 71.37||0.025|
Group 1; Control, Group 2; Exposed to simulated cell phone receiver waves (915 MHz) for 14 days, Group 3; Exposed to simulated cell phone receiver waves (915 MHz) for 21 days and Group 4: Exposed to simulated cell phone antenna waves (950 MHz) for 14 days.
The present research indicated that significant
decreased occurred for sperm viability, motility
and total antioxidant capacity in all exposure
groups compared with the control group. The comparison
between groups showed a significant decrease
in percentage of viability and motility with
increased duration of exposure from 2 to 3 weeks,
but it did not affect sperm total antioxidant capacity.
The results of the study were in agreement with
the findings of Agarwal et al. (
In a prospective study on 13 males with normal
semen analysis, Davoudi et al. (
As mentioned earlier, simulated cell phone
waves had no effect on sperm count in rats which
contrasted the results by Kesari et al. (
The results of the current study in terms of the
effect of cell phone waves on normal morphology
and sperm count contrasted those of other studies.
An observational study of 361 males was conducted
to determine if there was a correlation between
cell phone use and sperm morphology. Males were
divided into four groups: i. no use, ii.<2 hours/day,
iii. 2-4 hours/day and iv. >4 hours/day. They observed
a statistically significant difference in mean
normal morphology between the low and high cell
phone use group. Fejes et al. showed a significant
decrease in sperm count related to cell phone handling
The results of our study have revealed that cell
phone waves decrease sperm total antioxidant
capacity. A side effect of cell phone waves is increased
free radicals, thus our findings can partly be
due to the production of these harmful radicals (
This finding was in line with another study (
Oxidative stress generated in the testicular organ
due to cell phone exposure leads to a build-up of
free radicals and ROS levels in sperm. Sperms are
susceptible to damage from oxidative stress due to
the high content of polyunsaturated fatty acids in
their membranes and limited stores of antioxidant
On the other hand, a decrease in sperm motility
and viability is linked to the concentration of superoxide
anion in semen. When superoxide is produced
extracellulary, it can oxidize membrane phospholipids
and cause a decrease in viability (
Based on the findings of our study, it was possible that the effect of increased duration of exposure to cell phone waves (from 2 to 3 weeks) on the percentage of motility and viability was more than the increased frequency, and that the time of exposure to cell phone waves might be more important than cell phone frequency. Increased frequency (from 915 to 950 MHz) did not impact the percentage of motility and viability in rats. Similarly, increased frequency did not create a significant difference in sperm total antioxidant capacity in adult male rats.
It can also be concluded from the findings of this study that cell phone waves may, in addition to affecting sperm parameters, cause oxidative stress in the body and consequently create various diseases. Thus, because of the extensive use of cell phones, further research is required. It is recommended that more attention be paid to cell phone waves as a source of oxidative stress and exposure to these waves be decreased as much as possible. It is also suggested that individuals who spend more time on cell phones be monitored periodically in terms of reproductive system health and it is recommended that they consume a diet full of antioxidants in order to minimize the adverse effects of these waves.