Cellular phones and their base stations emit pulsed microwaves in the envir
onment. Cellular phone users are exposed in the near field and, under this
condition, a large part of the electromagnetic energy is absorbed by the he
ad, leading to an increased brain temperature. The general population is ex
posed under far field conditions to an electromagnetic intensity depending
on the distance from the base station, passive re-emitters, the number of c
ommunications maintained by the base station and their position in relation
to antennae (in front of the antenna or behind). Biological effects have b
een reported, such as radiofrequency sickness, electroencephalographic and
blood pressure changes and also cancer risks in humans and animals exposed
to microwave irradiation. Some European countries (Italy, France, Belgium,
etc.) have taken measures to protect their populations. (C) 2000 Editions s
cientifiques et medicales Elsevier SAS.