Tower
Power density is power per unit area. ICNIRP guidelines set density limits for occupational exposure and the public. For the public using GSM mobiles the limit has been kept at 4.5 W/sq m for 900 MHz and 9 W/sq m for 1,800 MHz. For CDMA phones it is 4W/sq m. Occupational exposure limits are five times the public limits.

Mobiles
Strength of the mobile signal determines the rate of radiation absorption by the body. Under ICNIRP guidelines, a mobile phone must adhere to the rate of 2 W/kg for exposure to the head and the trunk, while for the whole body exposure must not exceed 0.8 W/kg