The Effects Of Microwave Radiation On Male Reproductive Function And Offspring Sex Ratio

Radar operator is a special group which is very different from other professional personnel.They are continuously exposed to radar microwave radiation for a long time.Due to the work intensity and special requirements,radar operators are mostly men.For some reasons,little research has been done on whether the reproductive system of this special group is affected by radar microwave radiation,and conclusion has not been reached yet.In this study,the effects of radar microwave radiation on ratio of X and Y sperms were studied by epidemiological investigation.Then the effects of radar simulated microwave radiation on male reproductive function and sex ratio of offspring are analyzed by animal experiments,thus providing reference and theoretical basis for improving radar protection work more reasonably,avoiding potential damage caused by radar microwave radiation more scientifically and improving reproductive health level of male radar workers more effectively.Objective The aim of this study is to investigate the effects of microwave radiation on males’reproductive function and sex ratio of offspring.Methods1.Males were selected from a radar brigade.The subjects were divided into non-exposed group(0 year of exposure),exposed group 1(0.5-1.5 years of exposure),exposed group 2(1.5-3.0 years of exposure)and exposed group 3(more than 3 years of exposure).15 samples of semen samples were randomly selected from above four groups,and the effects of microwave radiation on ratios of X and Y sperms were analyzed by fluorescence in situ hybridization.2.Using ICR male mice as animal model,the simulated microwave radiation experiments with frequency of 2 GHz,intensity of 0 w/m~2(control group),0.5 w/m~2(experimental group 1),1.5 w/m~2(experimental group 2)and 2.5 w/m~2(experimental group 3)were carried out with reference to the radiation parameters measured during epidemiological investigation.After 8 weeks of irradiation,the serum testosterone levels,epididymal sperm count,sperm motility,malformation rate,testicular tissue morphology,the rate of apoptotic germ cells and the expression of Bax,Bcl-2,Caspase-3 were compared.3.After two weeks,four weeks and eight weeks of simulated radiation,the male mice in each group were mated with oestrus female mice with ratio of 1:3.Compare the pregnancy rate and litter number of the female mice after two and four weeks of radiation,as well as the placental weight,fetal weight and placental efficiency after eight weeks of radiation.Collect the 3.5 dpc,10.5 dpc and 18.5 dpc embryos and analyze sex ratio by double nested PCR,double PCR and naked eye’s identification.Results1.The effects of radar microwave radiation on the ratio of X and Y sperms:there was no significant difference in the ratio of X sperms to total sperms among the four groups(p=0.426).2.The effects of simulated microwave radiation on reproductive function of male mice:1)Sperm quantity,sperm motility and malformation rate:compared with the control group,the sperm quantity decreased in experimental group 1(p<0.05),significantly decreased in experimental group 2 and experimental group 3(p<0.01).The sperm activity decreased in experimental group 1 and 2(p<0.05),significantly decreased in experimental group 3(p<0.01).There was no significant difference in sperm malformation rate between groups(p>0.05).2)Testosterone level:compared with the control group,the level of testosterone in the three experimental groups decreased significantly(p<0.01),and the decrease degree was as follows:experimental group 3>experimental group 2>experimental group 1.3)Testicular tissue morphology:compared with the control group,the testicular organizational structure of the three experimental groups were damaged in different degrees,reflected in the shedding,disordering and agglomerating of spermatogenic cells,decreasing in sperm number by HE staining.Ultrastructural observation showed spermatogenic cells’s edema,degeneration,necrosis,as well as mitochondrial vacuole,endoplasmic reticulum expansion and so on.The damage degree was as follows:experimental group 3>experimental group 2>experimental group 1.4)The rate of apoptotic germ cells and the expression of Bax,Bcl-2,Caspase-3:compared with the control group,the rate of apoptotic germ cells increased in experimental group 1(p<0.05),significantly increased in experimental group 2 and experimental group 3(p<0.01).Bax and Caspase-3 scatterly expressed in the control group,increasingly expressed in experimental group 1 and experimental group 2,largely expressed in experimental group 3.Bcl-2 was largely expressed in the control group while the expression levels in the three experimental groups were significantly reduced.3.The effects of simulated microwave radiation on fertility of male mice and sex ratio of embryos:1)There was no significant difference in the pregnancy rate between the four groups after two and four weeks of radiation(p>0.05).Although there was no significant difference in the pregnancy rate between the four groups after eight weeks of radiation(p>0.05),but experimental groups had decreasing trends.There was no significant difference in the number of litters among groups(p>0.05).2)There was no significant difference in placental weight,fetal weight and placental efficiency among the four groups after eight weeks of radiation(p>0.05).3)In terms of offspring sex ratio,2473 embryos were identified at different stages(3.5 dpc,10.5 dpc,18.5 dpc).Chi-square test showed that there was no significant difference in offspring sex ratio among groups with different radiational intensity and weeks(p>0.05).Conclusion Microwave radiation caused some damage to male reproductive function and fertility,which was reflected in the decrese of sperm quantity,sperm activity and testosterone level,impairment of testicular tissue morphology,increase of the rate of germ cells,reduction of the pregnancy rate,while litter size,placental weight,fetal weight and placental efficiency were not affected.The out-of-balance in the ratio of X and Y sperms and the sex ratio of offspring has not been found in this study.More convincing evidences need to be investigated in large samples by epidemiological follow-up.