With the widespread use of mobile phones, laptops, and WIFI, the effects of radio frequency radiation (RFR) on human health are of increasing concern, and there are particular concerns about its reproductive toxicity. Studies have shown that the reproductive system is a sensitive target for RFR. In males, RFR is associated with decreased sperm quality and serum testosterone levels, but there are few studies on the biological effects of RFR by altering physical parameters on the male reproductive system. This paper introduced common sources of RFR, reviewed the toxic effects and mechanisms of RFR targeting male reproductive system from the aspects of spermatogenic cells, sperm structure, blood-testicular barrier, and testicular function, and analyzed male reproductive system related toxic effects of RFR by varying physical parameters including frequency, treatment duration, and specific absorption rate, so as to provide a theoretical basis and scientific basis for the safe and reasonable use of radio frequency electromagnetic field by humans and subsequent in-depth research.

BACKGROUND: Exposure to the ionizing radiation (IR) encountered outside the magnetic field of the Earth poses a persistent threat to the reproductive functions of astronauts. The potential effects of space IR on the circadian rhythms of male reproductive functions have not been well characterized so far. METHODS: Here, we investigated the circadian effects of IR exposure (3 Gy X-rays) on reproductive functional markers in mouse testicular tissue and epididymis at regular intervals over a 24-h day. For each animal, epididymis was tested for sperm motility, and the testis tissue was used for daily sperm production (DSP), testosterone levels, and activities of testicular enzymes (glucose-6-phosphate dehydrogenase (G6PDH), sorbitol dehydrogenase (SDH), lactic dehydrogenase (LDH), and acid phosphatase (ACP)), and the clock genes mRNA expression such as Clock, Bmal1, Ror-α, Ror-β, or Ror-γ. RESULTS: Mice exposed to IR exhibited a disruption in circadian rhythms of reproductive markers, as indicated by decreased sperm motility, increased daily sperm production (DSP), and reduced activities of testis enzymes such as G6PDH, SDH, LDH, and ACP. Moreover, IR exposure also decreased mRNA expression of five clock genes (Clock, Bmal1, Ror-α, Ror-β, or Ror-γ) in testis, with alteration in the rhythm parameters. CONCLUSION These findings suggested potential health effects of IR exposure on reproductive functions of male astronauts, in terms of both the daily overall level as well as the circadian rhythmicity.
ARNTL Transcription Factors/genetics* ; Acid Phosphatase ; Animals ; CLOCK Proteins/genetics* ; Circadian Rhythm/radiation effects* ; Epididymis/radiation effects* ; Gene Expression/radiation effects* ; Genitalia, Male/radiation effects* ; Glucosephosphate Dehydrogenase ; L-Iditol 2-Dehydrogenase ; L-Lactate Dehydrogenase ; Male ; Mice ; Mice, Inbred C57BL ; Models, Animal ; Nuclear Receptor Subfamily 1, Group F, Member 1/genetics* ; Nuclear Receptor Subfamily 1, Group F, Member 2/genetics* ; Nuclear Receptor Subfamily 1, Group F, Member 3/genetics* ; RNA, Messenger/genetics* ; Radiation Exposure ; Radiation, Ionizing ; Reproductive Physiological Phenomena/radiation effects* ; Sperm Motility/radiation effects* ; Spermatozoa/radiation effects* ; Testis/radiation effects*

Cerium oxide nanoparticles (CeO₂ NPs), as the oxides of the most abundant elements in rare earths, have been widely used in biomedical and industrial production and other fields that are closely related to human life. China is a large country in resources and production of rare earth, and the impact of CeO₂ NPs on human health has been increasingly concerned. In response to the possible health risks of CeO₂ NPs, researchers begin to focus on their toxic effects on living organisms, especially on the reproductive system. The male reproductive system is not only responsible for producing sperm and regulating the secretion of testosterone, but also plays a key role in maintaining male sexual characters and function. Any adverse effects on the male reproductive system may lead to reduced fertility and reproductive dysfunction. Some studies have shown that long-term exposure to CeO₂ NPs may lead to gonadal damage, sex hormone disorders, and other problems in male animals. Therefore, an in-depth study of the potential effects of CeO₂ NPs on the male reproductive system is of great scientific significance and practical value. In this study, we reviewed the male reproductive toxicity of CeO₂ NPs in terms of spermatogenic cells, spermatozoa structure, blood-testis barrier, hypothalamic-pituitary-gonadal axis, and functional changes in epididymis, and analyzed the effects of the size and shape of physicochemical parameters of CeO₂ NPs on the toxicity to male reproductive system. The findings will provide a theoretical basis and scientific evidence for the rational use of CeO₂ NPs.