Epidemiological study (observational study)

Symptoms experienced in connection with mobile phone use epidem.

By: Oftedal G, Wilen J, Sandström M, Hansson Mild K

Published in: Occup Med 2000; 50 (4): 237-245

Aim of study (acc. to author)

A cross-sectional study was conducted in Sweden and Norway to evaluate self-reported symptoms among mobile phone users in their jobs. The present publication includes the measures taken to reduce the experienced symptoms, conditions under which the symptoms were experienced and consequences with respect to medical consultations and sick leave.

Further details

The first part of the study comparing symptoms experienced by users of analog and digital mobile phones was published in Sandström et al. (2001).

Endpoint/type of risk estimation

subjective symptoms: dizziness, feelings of discomfort, difficulties concentrating, memory loss, unusual fatigue, headaches, sensations of warmth behind/ around/ on the ear, burning sensations in the facial skin, tingling/tightness sensations in the facial skin and other symptoms
details of symptom experience (e.g. duration of symptoms, medical consultation and sick leave), conditions under which the symptoms are experienced (e.g. long duration mobile phone calls), measures to reduce the symptoms

Type of risk estimation:

prevalence

Exposure

- PC/TV monitor
- mobile communications
- GSM
- NMT
- occupational
- personal

Assessment

list: company subscriber
questionnaire: transmitter system, calling time per day and number of calls per day

Exposure groups

Group	Description
Group 1	NMT users
Group 2	GSM users
Group 3	NMT and GSM users
Group 4	number of calls/day: < 2
Group 5	number of calls/day: 2 - 4
Group 6	number of calls/day: > 4
Group 7	calling time per day: < 2 min
Group 8	calling time per day: 2 - 15 min
Group 9	calling time per day: 15 - 60 min
Group 10	calling time per day: > 60 min

Population

Group:
- men
- women
Observation period: 1996
Study location: Sweden, Norway

Study size

Type	Value
Total	16,990
Participants	10,631

Other:

exact numbers and observation period in Sandström et al. (2001)

Statistical analysis method:

Chi-square test
ANOVA
t-test

Results (acc. to author)

Overall, 31 % of Norwegian respondents and 13 % of Swedish respondents had experienced at least one symptom in connection with mobile phone use, mainly warmth on the ear, burning sensations in facial skin, and headaches. Relatively few had consulted a physician or been on sick leave because of the symptoms but about 45 % had taken steps to reduce the mobile phone attributed symptoms, mainly in reducing the calling time and using hands-free equipment.
The authors concluded that the results suggest an awareness of the mobile phone attributed symptoms, but not necessarily a serious health problem.

Study funded by

Norwegian Post and Telecommunication Authority (NPT), Norway
Swedish Mobile Telecommunications Industry (MTB; MobilTeleBranschen)
Telenor, Norway
Work Environment Fund of the Confederation of Norwegian Business and Industry

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