Epidemiological study (observational study)

Mobile phone use and subjective symptoms. Comparison of symptoms experienced by users of analogue and digital mobile phones epidem.

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

Published in: Occup Med 2001; 51 (1): 25-35

Aim of study (acc. to author)

A cross-sectional study was conducted in Sweden and Norway to test the hypothesis that GSM users experience more self-reported symptoms while using mobile phones than NMT users. Further results of the study are published in publication 9860.

Endpoint/type of risk estimation

subjective symptoms: dizziness, discomfort, concentration, memory loss, fatigue, headaches, warmth behind ear, warmth on ear, burning skin, tingling/tightness

Type of risk estimation:

prevalence

(odds ratio (OR))

Exposure

- 450–900 MHz
- mobile communications
- analog mobile phone
- digital mobile phone
- 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
Reference group 1	NMT users
Group 2	GSM users
Reference group 3	NMT, calling time: < 2 min/day
Group 4	NMT, calling time: 2 - 15 min/day
Group 5	NMT, calling time: 15 - 60 min/day
Group 6	NMT, calling time: > 60 min/day
Reference group 7	GSM, calling time: < 2 min/day
Group 8	GSM, calling time: 2 - 15 min/day
Group 9	GSM, calling time: 15 - 60 min/day
Group 10	GSM, calling time: > 60 min/day
Reference group 11	NMT, < 2 calls/day
Group 12	NMT, 2 - 4 calls/day
Group 13	NMT, > 4 calls/day
Reference group 14	GSM, < 2 calls/day
Group 15	GSM, 2 - 4 calls/day
Group 16	GSM, > 4 calls/day

Population

Group:
- men
- women
Characteristics: company subscribers
Observation period: 1996
Study location: Sweden, Norway (southern part)

Study size

Type	Value
Total	16,990
Participants	10,631
Evaluable	6,392

Other:

NMT users: 2778; GSM users: 3614

Statistical analysis method:

logistic regression

Results (acc. to author)

No increased risk for subjective symptoms for GSM users compared with NMT users was observed. A lower risk for sensations of warmth on the ear was found for GSM users compared with NMT users.
The hypothesis that GSM users experience more self-reported symptoms while using mobile phones than NMT users was nullified.

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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