Acute and Chronical Biological Effects of W Band Millimetric Waves Exposure in Rats

Abstract

The biological effects of millimetric waves systems, MMW (e.g. 5G communications, automotive radars, or crowd control systems, ADS) systems are still scarcely investigated. Hairless rats were exposed to 2 94GHz continuous wave (MMW, CW), under acute high power conditions (3sec at10kW/m ) and under 2 environmental/professional lower power exposure (4 hours a day, for 5 days a week, for 6 months at 10mW/cm ). It was found that the 94 GHz acute exposure provoked the disappearance of the epidermis upper corneal layers and the increase of the inammatory gene expression SOCS-3 after 3Hrs. Besides, neither histological nor genetic modication could be observed after chronic 94 GHz exposure and after an acute and a chronic capsaicin exposure. Conclusions :After a powerful acute exposition a thermal effect is observable, associated with a localized inammatory response. After chronic, low power exposition, an hypoalgesia effect was found, possibly related with an increase in brain plasticity. Mechanistically, the hypothesis is based on low noise stimulation of thermal pain receptors at subthreshold level. Conversely, neither inammation nor no direct change in was found.