This animal and in vitro study examined non-thermal 900 MHz RF-EMF exposure during prenatal and postnatal development at 0.08 and 0.4 W/kg SAR. The authors report changes consistent with altered neurodevelopment, including reduced BDNF, reduced in vivo cell proliferation, and disrupted synaptic balance in rat pup brain regions. In vitro, exposed neural stem cells showed increased apoptosis and DNA double-strand breaks and shifts in cell populations toward glial lineages. The authors conclude that regulatory-level 900 MHz exposure can disrupt key neurodevelopmental processes in rodents.

This laboratory study tested combined effects of constant temperature and RF exposure on development of Aedes aegypti and Aedes albopictus from hatching to adult emergence. Temperature was reported as the primary determinant of developmental timing, with optimal development around 302C. RF exposure (900 MHz and 18 GHz) was described as a secondary factor that could accelerate or prolong development depending on temperature, with synergistic shortening at 250C and prolongation under suboptimal conditions.

This narrative review discusses low-intensity RF-EMF exposure, primarily from mobile phones, with a focus on thermoregulation and energy homeostasis. It reports that many rodent studies at 900 MHz describe cold-like thermoregulatory and behavioral responses and molecular findings suggestive of WAT browning, while BAT transcriptional changes typical of cold exposure were not observed. The authors indicate short-term adaptations may not disrupt homeostasis, but emphasize uncertainty about long-term consequences and call for further research, including at 5G-relevant frequencies.

This laboratory study examined whether a 900 MHz radiofrequency electromagnetic field (RF-EMF) influences the behavior of newly emerged honey bee workers. Compared with controls, the exposed groups showed behavioral changes, with some parameters showing statistically significant differences seven days after exposure. The authors frame RF-EMF as a potential environmental stressor and call for further research, including gene expression analyses.

This animal study exposed pregnant Sprague Dawley rats to a 900 MHz electromagnetic field for 1 hour daily throughout gestation and assessed offspring outcomes postnatally. Sciatic nerve analyses at postnatal day 60 indicated persistent morphological alterations attributed to prenatal EMF exposure. However, the reported changes were not severe enough to significantly affect measured functional outcomes (including electrophysiology and locomotor tests).

This animal study exposed male Wistar rats to 900 MHz RF-EMR from a mobile phone for 1 hour daily over four weeks and assessed behavior and tissue changes. The authors report altered contextual fear conditioning-related behavior in exposed rats. Histological assessments indicated apoptosis and enlarged perivascular space in the hippocampal CA3 region and apoptotic/inflammatory-like changes in the adrenal zona fasciculata, with no reported differences in adrenal medulla cytoarchitecture.

This animal study exposed juvenile and young adult Wistar rats to 5G (3.5 GHz) or 2G (900 MHz) radiofrequency fields (1.5 V/m) for 1–2 weeks and measured brown adipose tissue-related gene expression by RT-qPCR. The abstract reports significant downregulation of PRDM16 and C/EBP mRNA after 5G exposure, while UCP1-dependent thermogenesis markers were not significantly changed at the transcriptional level. The authors interpret these findings as a potential partial disruption of brown adipocyte differentiation and raise EMF safety concerns, while calling for further confirmatory research.

This National Toxicology Program technical report describes 900 MHz whole-body RFR exposures (GSM and CDMA) in male and female Sprague Dawley rats from in utero through up to 2 years. The report concludes clear evidence of carcinogenic activity in males for both modulations based on malignant schwannoma of the heart, with malignant glioma of the brain also reported as related to exposure. In females, the report concludes equivocal evidence of carcinogenic activity for both modulations based on selected tumor outcomes, and genetic toxicology findings were mixed with some comet assay increases/equivocal results but negative micronucleus assays.

This animal study exposed male Sprague-Dawley rats to 900 MHz GSM mobile phone RF radiation for 4 hours and assessed ERα promoter methylation in colon tissue. The authors report altered ERα methylation patterns versus controls after RF exposure. They also report no radioadaptive response in ERα methylation following a subsequent 3 Gy Co-60 gamma challenge.

This rat study examined whether pulse-modulated 900 MHz and 1800 MHz RF exposure affects blood-brain barrier permeability using Evans blue dye. The abstract reports increased permeability in male rats at both frequencies (stronger at 1800 MHz) and in female rats at 900 MHz but not at 1800 MHz. The authors suggest mobile-phone-like RF exposure could increase blood-brain barrier permeability under non-thermal conditions, while noting that further mechanistic studies are needed.

This animal study exposed 108 male Sprague-Dawley rats to 900 MHz EMF (1 mW/cm2) or sham for 14 or 28 days (3 h/day). The authors report that 28-day exposure was associated with impaired spatial memory, BBB permeability damage, and ultrastructural changes in hippocampus and cortex. They also report increased mkp-1 expression and ERK dephosphorylation, proposing activation of the mkp-1/ERK pathway as a mechanism.