Article Dans Une Revue Toxicology Letters Année : 2025

P04-16 Effects of 5G exposure on thyroid morphology and thyroid-mediated thermogenic functions

Résumé

Introduction: The introduction of the 3.5 GHz frequency band in the fifth generation (5G) network has vastly improved performances of wireless technologies. However, the biological effects of radiofrequency electromagnetic field (RF-EMF) exposure on health remain a major concern. RF-EMF can penetrate highly exposed tissues such as the thyroid gland, and potentially disrupting its functions in regulating thermogenesis and energy homeostasis [1]. The thyroid activation index (TAI) is a good indicator of thyroid activity. It is defined as the ratio of follicle volume to colloid volume [2]. The effects of RF-EMF exposure on this gland remain largely unexplored. This study is the first to investigate the impact of 5G (3.5 GHz) exposure on its morphological structures and glandular activity. First, we compared the follicular, epithelium and colloidal sizes of the follicles. Secondly, we measured the circulating levels of thyroid stimulating hormone (TSH) and thyroxine (T4) in serum. Thirdly, we assessed the key biomarkers involved in brown adipose tissue (BAT) thermogenesis and the browning of white adipose tissues (WAT), two thermogenic pathways regulated by thyroid activity. Methods: Three-week-old Wistar rats were non-exposed (control) or exposed to 3.5 GHz (5G) for 14 days with two exposure sessions of 1 hour daily. An intensity of 1.5 V/m was applied to mimic current environmental RF-EMF exposure and the whole-body specific absorption rate was estimated to 0.07 mW/kg. After the exposure period, thyroid tissues were collected for histological analysis. Serum concentrations of TSH and T4 were quantified using ELISA. The relative gene expression of BAT thermogenesis (UCP1, PPAR-α, PPAR-γ, PGC1-α, DiO2) and WAT browning (UCP1, PPAR-α, PPAR-γ, PGC1-α, PRDM16, Cidea, S100b, DiO2) biomarkers were analysed by RT-qPCR. For statistical analysis, Shapiro–Wilk was used for normality test. Then, student's t-test and Mann-Whitney were carried out to analyse parametric and non-parametric data respectively. Results: The follicles were significantly larger in the 5G-exposed rats compared to controls (p<0.05). The mean size of the follicular epithelium and colloid was also higher in the 5G group (p<0.05). The TAI is reduced after 5G exposure (p<0.05). However, such effects were not detected in the serum levels of TSH and T4. No significant transcriptional events were observed for BAT thermogenesis and WAT browning. A trending decrease was noted in DiO2 (p<0.1) and PPAR-α (p<0.1) in BAT. Conclusion: Our results suggest that 5G exposure may alter thyroid morphological structures, without significantly affecting its endocrine activity or its mediated-thermogenic functions. Inactive thyroid glands show enlarged follicles, flattened epithelium and abundant colloid, while active thyroids show smaller colloids and larger follicular epithelium. Finally, existing studies have not shown clear evidence so far linking RF-EMF exposure to thyroid dysfunction.

Fichier non déposé

Dates et versions

hal-05256369 , version 1 (15-09-2025)

Identifiants

Citer

C. Seewooruttun, B. Bouguila, M. Ramelet, A. Corona, S. Delanaud, et al.. P04-16 Effects of 5G exposure on thyroid morphology and thyroid-mediated thermogenic functions. Toxicology Letters, 2025, 411 (suppl. Abstracts of the 59th Congress of the European Societies of Toxicology (EUROTOX 2025)), pp.S86. ⟨10.1016/j.toxlet.2025.07.232⟩. ⟨hal-05256369⟩

Collections

48 Consultations
0 Téléchargements

Altmetric

Partager

  • More