A survey study using questionnaire, was conducted in 161 students and worke
rs in a French engineering school on symptoms experienced during use of dig
ital cellular phones. A significant increase in concentration difficult (p
< 0.05) was reported by users of 1800-MHz (DCS) cellular phones compared to
900-MHz (GSM) phone users. in users of cellular phones, women significantl
y (p < 0.05) complained more often of sleep disturbance than men. This sex
difference for sleep complaint is not observed between women and men non-us
ers of cellular phone. The use of both cellular phones and VDT significantl
y (p < 0.05) increased concentration difficulty. Digital cellular phone use
rs also significantly (p < 0.05) more often complained of discomfort, warmt
h, and picking on the ear during phone conversation in relation with callin
g duration per day and number of calls per day. The complaint warmth on the
ear might be a signal to users for stoping the call. (C) 2001 Editions sci
entifiques et medicales Elsevier SAS.