ABSTRACT
Many national and international exposure standards for maximum radiation exposure from the use of cell phones and other similar portable devices are ultimately based on the production of heat, particularly in regions of the head, that is, thermal effects (TE). The recent elevation in some countries of the allowable exposure, that is, averaging the exposure that occurs in a 6 min period over 10 g of tissue rather than over 1 g, allows for greater heating in small portions of the 10-g volume compared to the exposure that would be allowed averaged over a 1-g volume. There is concern that ‘hot’ spots, that is, momentary higher intensities, could occur in portions of the 10-g tissue piece, which might have adverse consequences, particularly in brain tissue.
There is another concern about exposure to cell phone radiation that has been virtually ignored except for the National Council of Radiation Protection and Measurements (NCRP) advice given in a publication in 1986 (National Council for Radiation Protection and Measurements, Biological Effects and Exposure Criteria for Radiofrequency Electromagnetic Fields, National Council for Radiation Protection and Measurements, 1986, 400 pp.). This NCRP review and guidance explicitly acknowledged the existence of non-thermal effects (NTE), and included provisions for reduced maximum-allowable limits should certain radiation characteristics occur during the exposure.
If we are to take most current national and international exposure standards as completely protective of thermal injury for acute exposure only (6 min time period), then the recent evidence from epidemiological studies associating increases in brain and head cancers with increased cell phone use per day and per year over 8–12 years raises concerns about the possible health consequences of NTE first acknowledged in the NCRP 1986 report (National Council for Radiation Protection and Measurements, Biological Effects and Exposure Criteria for Radiofrequency Electromagnetic Fields, National Council for Radiation Protection and Measurements, 1986, 400 pp.).
This paper will review some of the salient evidence that demonstrates the existence of NTE and the exposure complexities that must be considered and understood to provide appropriate, more thorough evaluation and guidance for future studies and for assessment of potential health consequences. Unfortunately, this paper is necessary because most national and international reviews of the research area since the 1986 report (National Council for Radiation Protection and Measurements, Biological Effects and Exposure Criteria for Radiofrequency Electromagnetic Fields, National Council for Radiation Protection and Measurements, 1986, 400 pp.) have not included scientists with expertise in NTE, or have not given appropriate attention to their requests to include NTE in the establishment of public health-based radiation exposure standards. Thus, those standards are limited because they are not comprehensive.
