DocumentsDate added

UMTS Base Station-like Exposure, Well-Being, and Cognitive Performance

21.04.2007

BACKGROUND: Radio-frequency electromagnetic fields (RF EMF) of mobile communication systems are widespread in the living environment, yet their effects on humans are uncertain despite a growing body of literature.

OBJECTIVES: We investigated the influence of a Universal Mobile Telecommunications System (UMTS) base station-like signal on well-being and cognitive performance in subjects with and without self-reported sensitivity to RF EMF.

METHODS: We performed a controlled exposure experiment (45 min at an electric field strength of 0, 1, or 10 V/m, incident with a polarization of 45° from the left back side of the subject, weekly intervals) in a randomized, double-blind crossover design. A total of 117 healthy subjects (33 selfreported sensitive, 84 nonsensitive subjects) participated in the study. We assessed well-being, perceived field strength, and cognitive performance with questionnaires and cognitive tasks and conducted statistical analyses using linear mixed models. Organ-specific and brain tissue–specific dosimetry including uncertainty and variation analysis was performed.

RESULTS: In both groups, well-being and perceived field strength were not associated with actual exposure levels. We observed no consistent condition-induced changes in cognitive performance except for two marginal effects. At 10 V/m we observed a slight effect on speed in one of six tasks in the sensitive subjects and an effect on accuracy in another task in nonsensitive subjects. Both effects disappeared after multiple end point adjustment.

CONCLUSIONS: In contrast to a recent Dutch study, we could not confirm a short-term effect of UMTS base station-like exposure on well-being. The reported effects on brain functioning were marginal and may have occurred by chance. Peak spatial absorption in brain tissue was considerably smaller than during use of a mobile phone. No conclusions can be drawn regarding short-term effects of cell phone exposure or the effects of long-term base station-like exposure on human health.

Hits: 1145

• Details
• Download
• View

500 uW/m2 verhoogt stress in lichaam meetbaar

21.04.2007

In Salzburg is een provocatieonderzoek gedaan vergelijkbaar met het TNO Cofam en ''het Zwitserse onderzoek''. Mensen werden kortstondig blootgesteld aan hoogfrequente elektromagnetische straling. Naast de invloed op het subjectieve welbevinden zijn ook monsters genomen (spuug). Er deden 57 proefpersonen mee en er was sprake van een gerandomiseerde en dubbelblinde opzet, wat placebo-effecten nagenoeg uitsluit.

Bij relatief lage vermogensdichtheden (500 uW/m2) werden al duidelijke biologische effecten gevonden. (n.b. de blootstellingslimiet in Nederland is 10.000.000 uW/m2)

Het lichaamseigen afweersysteem werd daadwerkelijk verzwakt. Biochemisch werd uit de speekselanalyse duidelijk dat hogere blootstellingen tot een relevante immuniteitsonderdrukking leidden. Zo was er een statistisch significante verandering in de cortisolspiegel (ook wel het stresshormoon genoemd. Daarnaast waren er opvallende veranderingen in het verloop van de alfa-amylase-spiegel (amylase is zetmeelverteringsenzym), wat tevens als een sterke stress-marker aan te merken is. Hetzelfde gold voor de immunoglobulin-A-spiegel (antilichamen in het speeksel).

Op het gebied van welbevinden werden geen statistisch significante effecten gemeten. Dit was te verwachten aangezien de opzet erg onhandig is om dit soort effecten te kunnen vinden. Zo was de blootstellingstermijn te kort en werd er wel wat rekening gehouden met voorbelasting, maar lang niet voldoende.

Hits: 542

• Details
• Download
• View

A Review Of The Potential Health Risk Of Radiofrequency Fields From Wireless ...

07.07.2006

A Review Of The Potential Health Risk Of Radiofrequency Fields From Wireless Telecommunication Devices

 

Hits: 848

• Details
• Download
• View

Untersuchungen an Probanden unter Exposition mit hochfrequenten elektromagnetischen Feldern...

07.07.2006

Untersuchungen an Probanden unter Exposition mit hochfrequenten elektromagnetischen Feldern von Mobiltelefonen 

Hits: 1331

• Details
• Download
• View

Subjective symptoms, sleeping problems, and cognitive performance living near mobile basestations

25.06.2006

BACKGROUND: The erection of mobile telephone base stations in inhabited areas has raised concerns about possible health effects caused by emitted microwaves. METHODS: In a cross-sectional study of randomly selected inhabitants living in urban and rural areas for more than one year near to 10 selected base stations, 365 subjects were investigated. Several cognitive tests were performed, and wellbeing and sleep quality were assessed. Field strength of high-frequency electromagnetic fields (HF-EMF) was measured in the bedrooms of 336 households.

RESULTS: Total HF-EMF and exposure related to mobile telecommunication were far below recommended levels (max. 4.1 mW/m2). Distance from antennae was 24-600 m in the rural area and 20-250 m in the urban area. Average power density was slightly higher in the rural area (0.05 mW/m2) than in the urban area (0.02 mW/m2). Despite the influence of confounding variables, including fear of adverse effects from exposure to HF-EMF from the base station, there was a significant relation of some symptoms to measured power density; this was highest for headaches. Perceptual speed increased, while accuracy decreased insignificantly with increasing exposure levels. There was no significant effect on sleep quality.

CONCLUSION: Despite very low exposure to HF-EMF, effects on wellbeing and performance cannot be ruled out, as shown by recently obtained experimental results; however, mechanisms of action at these low levels are unknown.

Hits: 888

• Details
• Download
• View