Short-Term In Vitro Exposure of Human Blood to 5G Network Frequencies: Do Sex and Frequency Additionally Affect Erythrocyte Morphometry?

<b>Background/Objectives</b>: This study assessed the effects of 5G radiofrequency electromagnetic radiation (RF-EMR) at different frequencies (700 MHz, 2500 MHz, 3500 MHz) on the complete blood count (CBC), erythrocyte morphometry, and platelet activation after the short-term in vitro exposure of human blood. <b>Methods</b>: Blood samples from 30 healthy volunteers (15 men and 15 women, aged 25-40 years old) were collected at three intervals (14 days apart). For each collection, four tubes of blood were drawn per volunteer-two experimental and two controls. Experimental samples were exposed to 5G RF-EMR for 2 h at room temperature using a half-cone gigahertz transverse electromagnetic cell. The CBC was analysed via a haematology analyser, the erythrocyte morphometry was analysed using the SFORM program, and platelet activation was analysed via flow cytometry. <b>Results</b>: The CBC and platelet activation showed no significant differences between the experimental and control samples. However, the erythrocyte morphometry exhibited notable changes. At 700 MHz, the erythrocyte size, contour, and membrane roughness increased significantly for both sexes, with women's cells showing greater sensitivity. At 2500 MHz, women exhibited an increased contour index and a decreased solidity and form factor. At 3500 MHz, women showed an increased contour index and outline but a decreased solidity, elongation, and form factor. Cluster analysis identified two erythrocyte subpopulations: smaller, rounder cells with smooth membranes and larger cells with rougher membranes. <b>Conclusions</b>: These results indicate that 5G RF-EMR exposure significantly alters erythrocyte morphometry. The strongest effects were observed at 700 MHz, where men exhibited greater membrane roughness, and women showed larger and rounder erythrocytes. These findings suggest that short-term in vitro 5G RF-EMR exposure disrupts the cytoskeleton, increasing membrane permeability and deformability.