Parental EMF occupational exposure and offspring neuroblastoma - no association
Neuroblastoma is a tumour that usually affects young children. In previous studies no consistent association has been shown between parental occupation involving electromagnetic field exposure and the incidence of neuroblastoma in their offspring.
To evaluate this further, De Roos and colleagues have analyzed data from a large, multicentre case-control study. They enrolled 538 cases and used detailed exposure information in their research. Although some slight increases in risk were seen with maternal exposure to radiofrequency radiation, the results were not statistically significant and were based on very few cases. The authors state that "overall, there was scant supportive evidence of strong associations between parental exposures in electromagnetic spectrum and neuroblastoma in the offspring".
De Roos AJ, Teschke K, Savitz DA, Poole C, et al. Parental occupational
exposures to electromagnetic fields and radiation and the incidence
of neuroblastoma in offspring. Epidemiology 2001;12:508-517.
In "What's New" of July 2000 we reported a study by De Pomerai and colleagues who found activation of the heat shock response in the soil nematode C. elegans exposed to RF energy (750 MHz) at an SAR of 0.001 W/kg. Although the heat shock response was first recognized in response to temperature elevation, it is an essential mechanism in the protection of cells from a variety of stresses.
Now French and colleagues hypothesize that exposure to mobile phones might induce or promote cancer via the heat shock response. They point out that the cellular response is characterized by the formation of heat shock proteins (Hsps), which protect cells against damage produced by stress. They cite evidence that Hsps can also play a role in cancer induction or promotion, though they state that there is debate as to whether the association with cancer is causal or correlative. They suggest that recurrent exposure to frequent mobile phone use could lead to chronic expression of Hsps in the brain tissue of users and that this in turn might induce or promote cancer. The authors state that this hypothetical mechanism should be tested experimentally.
French PW, Penny R, Laurence JA, McKenzie DR. Mobile phones, heat shock
proteins and cancer. Differentiation 2001;67:93-97.
Erdreich and Klauenberg have compared exposure standards in different countries. They review eight standards that satisfied four criteria: 1) derived by a scientific or technical organization from an examination of scientific data; 2) included some description of their approach; 3) included the general population instead of solely workers as the group to be protected; 4) available in English. Those reviewed were the standards of ANSI/IEEE, AUS/NZ, CENELEC, EU, Health Canada, NRCP, ICNIRP, and NRPB. In the energy-deposition range each used the same restriction, based on biological data and a 10-fold safety factor. There were different interpretations of the underlying biological data. The authors state that "harmonization of standards will require more detailed review and coordination of biological and engineering data and of policy options".
Erdreich LS, Klauenberg BJ. Radio frequency radiation exposure standards:
considerations for harmonization. Health Physics 2001;80:430-439.
In recent years there has been much discussion about the precautionary principle in relation to mobile phones. For instance, the Independent Expert Group on Mobile Phones in the UK advocated that "a precautionary approach to the use of mobile phone technologies be adopted until much more detailed and scientifically robust information on any health effects becomes available".
Three articles in the September 2001 edition of the American Journal of Public Health discuss the precautionary principle and public health. The second article considers the principle as it relates to electric and magnetic fields, but does not discuss radiofrequency radiation. Instead, it concentrates on the debate about power lines and childhood leukaemia. Overall, the articles provide a useful review of the issue.
D, Tickner J. Re-energizing public health through precaution. AJPH 2001;91:1351-1355.
Mobile phones are often helpful in medical emergencies. Now the authors of an article from Scotland offer another medical use. They placed the microphone of a mobile phone over the trachea of patients with and without asthma and transferred the sounds electronically by email and voice mail. They were able to clearly discriminate tracheal breath sounds in asthma. The authors suggest that this could be a useful method for monitoring airway diseases.
Reference: Anderson K, Qiu Y, Whittaker AR, Lucas M. Breath sounds, asthma, and the mobile phone. Lancet 2001;358:1343-1344.