A new method to determine laterality of mobile telephone use in adolescents

Abstract

Objectives As more children use mobile (cellular) telephones, public anxiety grows about the possible adverse health effects of radiofrequency (RF) exposure upon developing nervous systems. Most epidemiological studies investigating the health effects of mobile telephones have relied on self-reports from questionnaires. While there are some validation studies investigating the accuracy of self-reported mobile phone use in adults and adolescents, self-reported laterality of use has not been validated at any age. Although this study mainly sought to validate the accuracy of selfreported laterality of mobile telephone use in adolescents, investigation also covered number and duration of calls. Methods We monitored 455 calls in 30 students, mean age (SD) 14 (0.4) years. For 1 week, participants used hardware modified phones (HMPs) which logged dosimetric parameters such as laterality (side of head), date, number and duration of calls. These 'gold standard' measurements were compared with questionnaire selfreported laterality and estimated typical weekly phone use. Results Agreement between HMPs and self-reported laterality was modest (k¼0.3, 95% CI 0.0 to 0.6). Concordance between HMP measured and self-reported number of calls was fair (intraclass correlation coefficient (ICC)¼0.38, 95% CI 0.07 to 0.69), but poor for duration (ICC¼0.01, 95% CI 0.00 to 0.37) with wide limits of agreement for both. Conclusions These results suggest that adolescent selfreported laterality was of limited validity. Adolescent self-reported phone use by number and duration of calls was generally inaccurate but comparable to recent adult studies. Epidemiological studies of mobile phone use based on self-reported information may underestimate true associations with health effects.

Validating self-reported mobile phone use in adults using a newly developed smartphone application

“…Second, the smartphone app was installed on a regular modern smartphone. This made changes in phone use behaviour due to inconvenience about the phone model less likely 10. Still, the ‘non-Android users’ in our study, who used a smartphone provided by the study team, reported some changes in phone use behaviour, mainly an increase in data use.…”

“…This is one of the first studies that was able to assess the position in which the phone is held during voice calls, and to compare this with self-reported laterality. A previous study by Inyang et al 10 using hardware-modified phones among adolescents concluded that self-reported laterality was of limited value (κ=0.3), though it is not clear how they defined HMP-measured laterality. We made several important observations regarding laterality, which will have implications for modelling RF dose within the brain.…”

“…Moreover, these validation studies did not collect data on laterality and/or the use of hands-free devices, two important determinants of RF dose in the brain, used in studies on brain tumour risk. A potential risk from RF is expected to exist primarily on the side of the head where the phone is usually held (ipsilateral exposure) and, to a lesser extent, at the opposite side of the head (contralateral exposure) 10 11. Whether people can accurately recall the side of the head they generally held their phone is yet unknown.…”

Use of mobile phones and changes in cognitive function in adolescents

“…We used number of voice calls as exposure metric instead of duration of voice calls per week, because these have been found to be more accurate than the duration of calls. While studies on adolescents showed that adolescent recall of number of calls was moderate, self-report of duration of calls was poor in this age group 46 47. It would have been interesting to access more objective phone use data in calling records from providers to supplement the self-report calling data, however, it was not possible to access this information, mostly because adolescents in Australia chiefly use prepaid phones.…”

Interphone, IARC and radiofrequency fields: where to next?

“…Most previous studies of brain tumours and mobile phone use have used exposure surrogates, such as number and duration of calls, which are known to involve considerable random error3 and importantly for cancer studies may involve differential recall errors in more distant times 4. TCSE was presumed by the authors to represent a more biologically-relevant metric of RF exposure.…”