The ZIP9-centered androgen pathway compensates for the 2605 MHz radiofrequency electromagnetic radiation-mediated reduction in resistance to H2O2 damage in Sertoli cells of adult rats.

The direct biological effects of radiofrequency electromagnetic radiation (RF-EMR) from wireless communication equipment on the testes are still unclear. Our previous study proved that long-term exposure to 2605 MHz RF-EMR gradually damage spermatogenesis and resulted in time-dependent reproductive toxicity by directly disrupting blood-testis barrier circulation. Although short-term exposure did not cause readily observable damage to fertility, whether it caused specific biological effects and how these effects contributed to the time-dependent reproductive toxicity of RF-EMR were currently unknown. Studies on this issue are important for elucidating the time-dependent reproductive toxicity of RF-EMR. The present study established a 2605 MHz RF-EMR (SAR=1.05 W/Kg) scrotal exposure model with rats and extracted primary Sertoli cells for exposure to investigate the direct biological effects of short-term RF-EMR exposure on the testis. The results showed that short-term RF-EMR exposure did not decrease sperm quality and spermatogenesis, but it increased the levels of testicular testosterone (T) and zinc transporter 9 (ZIP9) in Sertoli cells of rats. In vitro, 2605 MHz RF-EMR exposure did not increase the apoptosis rate of Sertoli cells, but it increased the apoptosis rate and MDA of Sertoli cells exposed to H2O2. T reversed these changes and increased ZIP9 level in Sertoli cells, whereas inhibiting ZIP9 expression significantly suppressed these T-mediated protective effects. Moreover, T increased the levels of phosphorylated inositol-requiring enzyme 1 (P-IRE1), phosphorylated protein kinase R (PKR)-like endoplasmic reticulum kinase (P-PERK), phosphorylated eukaryotic initiation factor 2a (P-eIF2a) and phosphorylated activating transcription factor 6 (P-ATF6) in Sertoli cells, and these effects were reversed by ZIP9 inhibition. With prolonged exposure time, testicular ZIP9 was gradually downregulated, and testicular MDA increased. ZIP9 level was negatively correlated with MDA level in the testes of exposed rats. Thus, although short-term exposure to 2605 MHz RF-EMR (SAR=1.05 W/kg) did not significantly disturb spermatogenesis, it suppressed the ability of Sertoli cells to resist external insults, which was rescued by enhancing the ZIP9-centered androgen pathway in the short term. Increasing the unfolded protein response might be an important downstream mechanism involved. These results promote a better understanding of the time-dependent reproductive toxicity of 2605 MHz RF-EMR.

Current progress on the effect of mobile phone radiation on sperm quality: An updated systematic review and meta-analysis of human and animal studies.

Potential suppression of fertility due to mobile phone radiation remains a focus of researchers. We conducted meta-analyses on the effects of mobile phone radiation on sperm quality using recent evidence and propose some perspectives on this issue. Using the MEDLINE/PubMed, Embase, WOS, CENTRAL, and ClinicalTrials.gov databases, we retrieved and screened studies published before December 2020 on the effects of mobile phone use/mobile phone RF-EMR on sperm quality. Thirty-nine studies were included. Data quality and general information of the studies were evaluated and recorded. Sperm quality data (density, motility, viability, morphology, and DFI) were compiled for further analyses, and we conducted subgroup, sensitivity, and publication bias analyses. The pooled results of human cross-sectional studies did not support an association of mobile phone use and a decline in sperm quality. Different study areas contributed to the heterogeneity of the studies. In East Europe and West Asia, mobile phone use was correlated with a decline in sperm density and motility. Mobile phone RF-EMR exposure could decrease the motility and viability of mature human sperm in vitro. The pooled results of animal studies showed that mobile phone RF-EMR exposure could suppress sperm motility and viability. Furthermore, it reduced sperm density in mice, in rats older than 10 weeks, and in rats restrained during exposure. Differences regarding age, modeling method, exposure device, and exposure time contributed to the heterogeneity of animal studies. Previous studies have extensively investigated and demonstrated the adverse effects of mobile phone radiation on sperm. In the future, new standardized criteria should be applied to evaluate potential effects of mobile phone RF-EMR dosages. Further sperm-related parameters at the functional and molecular levels as well as changes in biological characteristics of germ cells should be evaluated. Moreover, the impact of mobile phone RF-EMR on individual organs should also be examined.

Long-term exposure to 4G smartphone radiofrequency electromagnetic radiation diminished male reproductive potential by directly disrupting Spock3-MMP2-BTB axis in the testes of adult rats.

The correlation between long-term exposure to SRF-EMR and the decline in male fertility is gradually receiving increasing attention from the medical society. While male reproductive organs are often exposed to SRF-EMR, little is currently known about the direct effects of long-term SRF-EMR exposure on the testes and its involvement in the suppression of male reproductive potential. The present study was designed to investigate this issue by using 4G SRF-EMR in rats. A unique exposure model using a 4G smartphone achieved localized exposure to the scrotum of the rats for 6 h each day (the smartphone was kept on active talk mode and received an external call for 1 min over 10 min intervals). Results showed that SRF-EMR exposure for 150 days decreased sperm quality and pup weight, accompanied by testicular injury. However, these adverse effects were not evident in rats exposed to SRF-EMR for 50 days or 100 days. Sequencing analysis and western blotting suggested Spock3 overexpression in the testes of rats exposed to SRF-EMR for 150 days. Inhibition of Spock3 overexpression improved sperm quality decline and alleviated testicular injury and BTB disorder in the exposed rats. Additionally, SRF-EMR exposure suppressed MMP2 activity, while increasing the activity of the MMP14-Spock3 complexes and decreasing MMP14-MMP2 complexes; these results were reversed by Spock3 inhibition. Thus, long-term exposure to 4G SRF-EMR diminished male fertility by directly disrupting the Spock3-MMP2-BTB axis in the testes of adult rats. To our knowledge, this is the first study to show direct toxicity of SRF-EMR on the testes emerging after long-term exposure.

Natural radioactivity levels in topsoil from the Pearl River Delta Zone, Guangdong, China.

Concentrations of the natural radionuclides ²³8U, ²²6Ra, ²³²Th and 4°K have been measured by γ-ray spectrometry in 796 topsoil samples from the Pearl River Delta Zone (PRDZ) of Guangdong, China. The mean concentrations for ²³8U, ²²6Ra, ²³²Th and 4°K were found to be 140 ± 37 Bq kg⁻¹, 134 ± 41 Bq kg⁻¹, 187 ± 80 Bq kg⁻¹ and 680 ± 203 Bq kg⁻¹ dry mass, respectively. These values were all higher than the mean values in soil for China and the world. Outdoor air-absorbed dose rates, calculated from activity concentrations of ²²6Ra, ²³²Th and 4°K, ranged from 86 to 237 nGy h⁻¹, with a mean value of 165 ± 46 nGy h⁻¹. The corresponding annual outdoor effective dose rate per person was estimated to be between 0.11 and 0.29 mSv y⁻¹, with a mean value of 0.20 ± 0.06 mSv y⁻¹, which was also higher than the world mean value of 0.07 mSv y⁻¹. The radium equivalent activity (Ra(eq)) and the external hazard index (I(r)) resulted from the natural radionuclides in soil, were also calculated and found to vary from 230 to 676 Bq kg⁻¹ and from 0.6 to 1.8, respectively. The Ra(eq) and the I(r) in all the investigated regions were up to 75% higher than the set limits of 370 Bq kg⁻¹ and 1.0, respectively.

[Competitive sorption of mixed organic pollutants by soils].

Binary sorption equilibria were measured using three different loading methods: METHOD (1): Naphthalene loaded before phenanthrene; Method (2): Both Solutes loaded simultaneously; Method (3): Naphthalene loaded after phenanthrene. Each having 110 reactors and 10 levels of initial concentrations for both tested organic solutes. This is very different from previous studies which employed one single initial concentration of the primary solute and multiple concentration levels of the competitor and loaded both solutes simultaneously. Results indicate that the adsorption behavior of the same solute on the same sorbent with competing solute is distinctly different from its single adsorption behaviors. Naphthalene isotherm becomes more linear as phenanthrene concentration increases in the binary systems tested using all three loading methods. In contrast, phenanthrene isotherm remains nonlinear when it was loaded after or loaded simultaneously with naphthalene. It becomes more linear as a function of naphthalene concentration only when phenanthrene was loaded before naphthalene. The Koc values decrease as a function of competing solute concentration (c(e)), and approach to the lowest value when this c, is about 0.5 Sw. IAST provides better predictions for the sorption only when the competing solute is at lower c(e)(< 0.01 Sw). Large-size and more hydrophobic phenanthrene competes favorably with the small-size and relatively less hydrophobic naphthalene, and the heterogeneity of natural organic matter associated with the soil may have strong influence on the competitive phenomena between the tested solutes.