RESUMEN
Concern has been raised regarding the possible effects of mobile phone use on health, especially by children and adolescents. Thus, it is important to evaluate factors affecting their patterns of use. This study aimed to identify determinants of heavy mobile phone use among Israeli adolescents. Data were collected using a self-report questionnaire regarding mobile phone usage, leisure activity, sociodemographics, and opinion regarding mobile phone use. "Heavy use" was defined as >1 hour of daily duration of voice calls, or >50 daily text messages. The survey included 1,688 seventh and ninth graders in eight middle schools. The vast majority (96.1 percent) used the mobile phone for voice calls daily. Girls were heavier users than boys, and ninth graders were heavier users than seventh graders. Among students attending religious schools, the rate of heavy users was lower than among those attending secular schools. About half of the students did not use hands-free devices at least half of the time. Leisure activities were significantly associated with mobile phone use. This study demonstrates that several variables, including sociodemographics and leisure activities, may predict heavy mobile phone use among teenagers. This information can be useful for exposure assessment and for designing intervention programs for reducing radio frequency (RF) radiation exposure.