The present study aims at analysing the level of exposure to non-ionizing radiation for the population of the cities. This type of EM (electromagnetic radiation) is generated mainly by GSM (Global System for Mobile Communication) technology of wireless communication based on the electromagnetic emitters (GSM antennas) needed for covering wider territorial areas. They produce constant pulsed microwave radiation even when nobody is using the phone, affecting the people inside and outside public and residential buildings. The study is based on the statistical evaluation and research of relevant scientific contributions, both stressing upon UN and European Parliament Regulations. There are considered the average threshold values for non-thermal biological effects in order to establish the potential risk for harmful exposure inside cities. Finally, there are considered some prevention and minimization procedures for residential exposure as long as non-thermal effects are not considered in any official standard and guideline.