http://www.jbpe.ir/Journal_OJS/JBPE/index.php/jbpe/article/view/1225/558
Excerpts:
The depth of penetration in human tissue (skin, muscle and tissues with high water content) for a frequency of 10 GHz which lies in 5G frequency spectrum is about a few mm. Given this consideration, high frequency 5G radiofrequency electromagnetic fields (RF-EMF) easily penetrate living skin cells and can make them severely damaged.
The low penetration and very high energy deposition per unit distance of 5G can lead to generation of high levels of free radicals in a short distance which in turn increases the risk of skin cancer.
In summary, although 5G technology brings new risks, it should be noted that regarding mobile phone use and cancer, the level of exposure is a factor that really matters.