The widespread, nationwide diffusion of sources of low (high voltage power lines and delivery network) and high frequency (radio-base stations, radio-TV implants…) sources of electromagnetic fields raises the question of the evaluation of background levels of electromagnetic fields in the environment, in order to characterize the exposure conditions of the general public, and to verify the compliance with exposure limits defined by national and international regulations. This assessment is particularly important in sensitive areas (schools, hospitals) where the prolonged permanence of sensitive subjects like children and elders is foreseen. Moreover, the employment of technologies based on non-ionizing electromagnetic fields in industrial and sanitary frameworks, and, more in general, in working environments, raises the issue of the evaluation of occupational risk associated to this type of exposure.