This animal study examined thyroid histomorphometry in juvenile male Wistar rats after 2 weeks of 5G EMF exposure (3.5 GHz, 1.5 V/m). Exposed rats showed larger follicle and colloid areas and a significantly lower Thyroid Activation Index, which the authors interpret as thyroid hypoactivity. The authors suggest this may represent a potential health risk and call for further work including hormone assays and mechanistic studies.

This animal study exposed adult male rats to 2.45 GHz Wi‑Fi from an active router for 4 or 24 hours daily over eight weeks and assessed reproductive organ histology and sperm parameters. The authors report histological changes in testes and epididymis, multifocal atypical hyperplasia in seminal vesicles, reduced seminiferous tubule diameter, and reduced spermatogenesis index in exposed groups. Sperm concentration decreased in both exposed groups, motility decreased in the 4-hour group, and viability increased in the 24-hour group, leading to an overall interpretation of potential reproductive risk under the studied conditions.