RF exposure and melatonin production
Results of previous studies on melatonin production after RF exposure have been inconsistent. Most have shown no effect. Wood and colleagues exposed 55 volunteers to 895 MHz RFR for 30 minutes. Output of a melatonin metabolite was the same in exposed compared with control subjects in one measure. By another method of measurement the pre-bedtime output of melatonin was decreased in the RFR-exposed subjects. This was entirely due to 4 individuals who had outputs that were extreme "outliers" compared to the others. It was thought that this was due to this small group having delayed onset of melatonin production, or some confounding factor e.g. prior exposure to bright light before coming to the laboratory.
For more, see "Research - Clinical - Hormone secretion".
Wood AW, Loughran SP, Stough C. Does evening exposure to mobile phone
radiation affect subsequent melatonin production? Int J Radiat Biol
people complain of electrical hypersensitivity (EHS) - see "What's
New, June '02, April '03, September
'05, and April '06". However, when
people with EHS have been tested in controlled trials, they have been
unable to detect the RF-exposure condition, as opposed to a sham-exposure.
Wilen and colleagues carried out a number of physiological measurements
and cognitive tests on subjects who complained of symptoms related to
mobile phones, but who did not complain of EHS. There were no significant
differences related to RF exposure between cases and controls. There
was increased heart rate variability in the cases during a critical
flicker fusion threshold test and a memory test.
Wilen J, Johansson A, Kalezic N, Lyskov E, et al. Psychological tests
and provocation of subjects with mobile phone related symptoms. Bioelectromagnetics
There have been few studies of the effect of RF exposure on immune function. Tuschl and colleagues tested the effect of short-term exposure from a GSM Basic signal on human lymphocytes and monocytes. They found no evidence that the RF exposure had any effect on the numerous tests of immune function that they performed.
For more, see “Research – Toxicological – Others -Immune system”.
Tuschl H, Novak W, Molla-Djafari H. In vitro effects of GSM modulated
radiofrequency fields on human immune cells. Bioelectromagnetics 2006;27:188-196.
Merola and colleagues did experiments on a neuroblastoma cell line. This is a solid tumour, mainly found in children. They exposed the cells to RFR from a 900 MHz signal for up to 72 hours. They found no alterations in cell death, proliferation, or differentiation in the exposed cells, when compared with sham-exposed cells.
For more, see "Research - Toxicological - Others - Cell death".
Merola P, Marino C, Lovisolo GA, Pinto R, et al. Proliferation and apoptosis
in a neuroblastoma cell line exposed to 900 MHz modulated radiofrequency
field. . Bioelectromagnetics 2006;27:164-171.
analyses from Hardell's group
The results from this group are consistently different from those of others who have studied this problem. The reasons for this are debated in epidemiological circles. For more, see "Research - Epidemiology".
Hardell L, Carlberg M, Mild KH. Pooled analyses of two case-control
studies on use of cellular and cordless telephones and the risk for
malignant brain tumours diagnosed in 1997-2003. Int Arch Occup Environ
Health 2006;published on-line March 16.