Danish study on cell phones and cancer
Last month we reported that a Swedish study showed no association between use of cell phones and brain cancer. Now a Danish study, also part of the large-scale INTERPHONE study, has reported similar findings. The authors studied 252 people with glioma and 175 with meningioma, and compared their cell phone use with control persons who did not have the disease. They found no association between phone use and an increased risk of brain tumour.
For more, see "Research - Epidemiology".
Christensen HC, Schuz J, Kosteljanetz M, Skovgaard Poulsen H, et al.
Another study shows no effect of long-term EMF on animal cancer
Numerous studies have shown no effect of electromagnetic field (EMF) exposure on cancer development in animals. The latest study, by Sommer and colleagues, used a strain of mice susceptible to a type of lymphoma. The mice were exposed for 24 hours per day, 7 days a week, for almost a year, at a whole-body SAR of 0.4 W/kg. There was no effect on survival rate in the exposed group, compared with a sham exposed, although both groups had a very high mortality rate from lymphoma, and it may have been difficult to show a difference.
For more, see "Research - Toxicological Experiments - cancer studies".
Sommer AM, Streckert J, Bitz AK, Hansen VW, et al. (2004): No effects
of GSM-modulated 900 MHz electromagnetic fields on survival rate and
spontaneous development of lymphoma in female AKR/J mice. BMC Cancer
2004;4:77. Published online November 11, 2004.
Influence of EMFs on plant growth
There have been only a few investigations on the effect of radiofrequency radiation (RFR) on plant growth. A recent study examined the effect of fields at frequencies of 400, 900, and 1900 MHz, at different field strengths, on duckweed (Lemna minor). The authors found that plant growth was decreased in several different situations.
Tkalec M, Malaric K, Pevalek-Kozlina B (2005): Influence of 400, 900,
and 1900 MHz electromagnetic fields on Lemna minor growth and peroxidase
activity. Bioelectromagnetics 26:185-193.
EMFs produce stress-like response in lymphocytes
Belyaev and colleagues investigated the response of lymphocytes from healthy subjects and from persons reporting hypersensitivity to EMFs. They found that the EMFs did not produce cell death, but did show other changes that were similar to those seen with the stress response. The lymphocytes from the healthy and hypersensitive donors showed comparable responses.
For more, see "Research -Toxicological Experiments - Others - apoptosis".
Belyaev IY, Hillert L, Protopopova M, Tamm C, et al. 915 MHz microwaves
and 50 Hz magnetic field affect chromatin conformation and 53 BPI foci
in human lymphocytes from hypersensitive and healthy persons. Bioelectromagnetics
Reevaluation and improved design of the TEM cell
In 1997 Penafiel and colleagues published a paper describing an increase in ornithine decarboxylase (ODC) activity in mouse fibroblasts after exposure to pulsed radiofrequency fields from a TDMA system operating at 835 MHz. ODC activity is increased in the unregulated growth of tumour cells. In view of the importance of this study, the WHO recommended its replication, and this is planned as part of European Project PERFORM B.
Nikoloski and colleagues have reevaluated the TEM cell system, which is an integral part of Penafiel's experiment. They found that the results they obtained for SAR and temperature measurements did not correspond with those of Penafiel and colleagues. Nikoloski et al. recommended several design changes in the TEM cell that led to consistent results for SAR values and temperature control.
Nikoloski N, Frohlich J, Samaras T, Schuderer J, Kuster N (2005): Reevaluation
and improved design of the TEM cell in vitro exposure unit for replication
studies. Bioelectromagnetics 26:215-224.
The authors of a recent publication define the " precautionary principle" as one that "recommends that action should be taken to prevent serious potential harm, regardless of scientific uncertainty as to the likelihood, magnitude, or cause of that harm". This subject has been discussed in "What's New" in November '01, April '02, and August '03. Wiedemann and Schutz carried out two experiments that "indicate that precautionary measures may trigger concerns, amplify EMF-related risk perceptions, and lower trust in public health protection".
Reference: Wiedemann PM, Schutz H. The precautionary principle and risk perception: experimental studies in the EMF area. Environ Health Perspect 2005;113:402-5.