November 2002

Another paper by Hardell and colleagues

In the August '02 edition of "What's New" we discussed an article from a study by Hardell and colleagues from Sweden. These authors have now published another paper based on the same study. In the latest publication they have concentrated on malignant tumours of the brain, whereas the earlier paper looked at both benign and malignant tumours. The results are essentially the same as in the first paper. Overall, there was no increased risk from exposure to various types of phone, but subgroup analyses showed some statistically significant results.

These authors continue to have results at variance from other researchers. It is noteworthy that the cases were not "incident" cases - that is, they were not identified immediately after the diagnosis, but were those cases diagnosed over a 3 year period and still alive at the time of the study. This increases the chance of reporting bias. For more details, see "Research - Epidemiology".

Reference: Hardell L, Mild KH, Carlberg M (2002): Case-control study on the use of cellular and cordless phones and the risk for malignant brain tumours. International Journal of Radiation Biology 78:931-936.

RF radiation does not produce DNA damage - two more studies

In "Research - Toxicological Experiments - cancer studies" we review the research that has been done on the effect of radiofrequency (RF) radiation on DNA. Two reports from Health Canada now add to this body of research. McNamee and associates exposed human white blood cells for two hours to a 1.9 GHz RF field that was pulse-modulated in one experiment and continuous-wave in the second. There was no evidence of DNA damage in either experiment.

References: McNamee JP, Bellier PV, Gajda GB, Miller SM, et al. DNA damage and micronucleus induction in human leukocytes after acute in vitro exposure to a 1.9 GHz continuous-wave radiofrequency field. Radiation Research 2002;158:523-533.

McNamee JP, Bellier PV, Gajda GB, Lavallée, et al. DNA damage in human leukocytes after acute in vitro exposure to a 1.9 GHz pulse-modulated radiofrequency field. Radiation Research 2002;158:534-537.