Categorization of Mobile Phones for Exposure Assessment in Epidemiological Studies on Mobile Phone Use and Brain Cancer Risk

For the purpose of exposure assessment in epidemiological studies on mobile phone use and brain cancer risk, 76 Japanese mobile phones were classified, for different use conditions (mobile phone held on left or right side of face, in tilt or cheek position, with the antenna in or out), into a small number of categories by using a cluster analysis of spatial patterns of their distribution of a specific absorption rate (SAR). The SAR distributions of the phones generally clustered according to a number of external characteristics, except for phones measured in the tilt/antenna in conditions. Typical 3-D SAR distributions in the head of a realistic numerical model were estimated for three different use conditions (cheek/antenna out, cheek/antenna in, tilt/antenna out) and each phone category.