ID Number		159
Study Type		Epidemiology
Model		RF exposure including 900 MHz (NMT/CW, GSM) of humans and analysis of idiopathic environmental intolerance (electrohypersensitivity such as headache and fatigue).
Details		Human subjects (n=6379 GSM & 5613 NMT in Sweden; n=2500 GSM & 2500 NMT in Norway) randomly selected from subscription registers where a company was the subscriber, but an individual was assigned the phone. Questionnaires were distributed (response rate 64% Sweden, 76% Norway) to gather information on exposure (on mobile phone history), symptoms (general and phone related), and confounding factors. The original hypothesis was that GSM (digital) users experience more symptoms than NMT (analogue) users. This hypothesis was not confirmed, although the investigators reported a statistically significant lower risk for warmth sensation in the proximity of the ear for GSM users than for NMT users. A similar trend was observed for headache in the Swedish data. A statistically significant association between calling time & number of calls per day (for both GSM and NMT phones) and ear warming, headache, and fatigue was reported. The frequency of headache and fatigue was much greater in Norway than Sweden, and the investigators offer as a possible explanation the lower base station density in Norway, which causes a generally higher phone output power. In a follow-up study by Oftedal et al, users in Sweden (n=481) and Norway (n=1152) that used BOTH NMT and GSM phones were questioned for symptoms resulting from use of their cellular telephones. Only the Swedish subgroup of the original study reported an elevation in complaints of discomfort, tingling & tightness, and "other symptoms" (concentration, memory loss, warmth behind or around the ear, burning skin). There were no differences in the reported effects from either Swedish or Norwegian respondents between GSM and NMT use. The final report is available on the internet "www.nilw.se/fakta/ summery.pdf". A study by Wilen et al (2003) did attempt to measure (maximal) SAR values in different locations within the head associated with different mobile phone handset models, and integrate this SAR information into estimated time of use and prevalence of subjective symptom data from their prior studies. These studies suggested a variability of ~40% for local SAR values associated with user variability, anatomical differences, and measurement procedures. The authors did not take into account power control variations, although they assumed this variability was randomly distributed and thus relatively constant within the sample cohort under study. They conclude that SAR values alone do not correlate with subjective symptoms until time of use is taken into account.
Findings		Effects
Status		Completed With Publication
Principal Investigator		National Institute for Working Life, Sweden - mild@niwl.se
Funding Agency		NIWL, Sweden
Country		SWEDEN
References		Wilen, J et al. Bioelectromagnetics, (2003) 24:152-159 Sandstrom, J et al. Occup. Med.,, (2001) 51:25-35 Oftedal, G et al. Occup. Med., (2000) 50:237-245 Mild, KH et al. Report, National Institute of Working Life, Sweden, (1998) :- Schmiedchen, K et al. Environmental Health., (2019) 18:88- Ledent, M et al. Bioelectromagnetics., (2020) 41:425-437 Oftedal, G et al. Reviews on Environmental Health. , (2021) :-
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