ID Number		1647
Study Type		Epidemiology
Model		MoRPhEUS: 900 MHz (GSM) mobile phone use by teenagers and analysis of recall ability
Details		Students (age 13-17) (n = 59) were provided with modified mobile phones that record time of use and subsequently asked to also recount their use for comparison. The authors report modest agreement between self reported number of calls when checked against the data recorded on the modified phones, but poor agreement between self reported duration and measured phone data(rho= 0.1, P = 0.37). Participants whose parents belonged to the 4th socioeconomic strata recalled mobile phone use better than others (rho = 0.6, P=0.01). In a subsequent study, the authors found only "fair" recall ability regarding laterality when questionnaire responses were checked with data collected on modified mobile phones (kappa value of 0.3; 95% CI = 0.0-0.6). Interestingly, the fact that individuals were either right or left handed did not dictate consistent mobile phone use on one side of the head or the other. There was also only "fair" agreement on recall of number of calls, and "poor" agreement on call duration. The authors conclude that adolescent recall of mobile telephone use was only modestly accurate, and caution is warranted in interpreting results of epidemiological studies investigating health effects of mobile phone use in this age group. In a larger analysis done as part of the MoRPhEUS study involving 317 students from 20 secondary schools and using a modified INTERPHONE questionnaire, the authors report significant mobile phone use overall (94%) with no correlation between recalled laterality and handedness, but there were correlations observed between cumulative use by the children and the percieved risk by the parents (OR = 4.06, 95% CI 0.97-17.09, p = 0.05) as well as the children's psychoticism index (IRR = 1.06, 95% CI 1.01-1.11, p = 0.03) [psychoticism is one of the 3 index measures of personality, the other two being extraversion and neuroticism]. AUTHORS' ABSTRACT: Redmayne et al. 2013 (IEEE #5576): There is ongoing concern that extended exposure to cell phone electromagnetic radiation could be related to an increased risk of negative health effects. Epidemiological studies seek to assess this risk, usually relying on participants' recalled use, but recall is notoriously poor. Our objectives were primarily to produce a forecast method, for use by such studies, to reduce estimation bias in the recalled extent of cell phone use. The method we developed, using Bayes' rule, is modelled with data we collected in a cross-sectional cluster survey exploring cell phone user-habits among New Zealand adolescents. Participants recalled their recent extent of SMS-texting and retrieved from their provider the current month's actual use-to-date. Actual use was taken as the gold standard in the analyses. Estimation bias arose from a large random error, as observed in all cell phone validation studies. We demonstrate that this seriously exaggerates upper-end forecasts of use when used in regression models. This means that calculations using a regression model will lead to underestimation of heavy-users' relative risk. Our Bayesian method substantially reduces estimation bias. In cases where other studies' data conforms to our method's requirements, application should reduce estimation bias, leading to a more accurate relative risk calculation for mid-to-heavy users. AUTHORS' ABSTRACT: Leung, Croft et al. 2011 (IEEE #6326): OBJECTIVE: This study examined sensory and cognitive processing in adolescents, young adults and older adults, when exposed to 2nd (2G) and 3rd (3G) generation mobile phone signals. METHODS: Tests employed were the auditory 3-stimulus oddball and the N-back. Forty-one 13-15 year olds, forty-two 19-40 year olds and twenty 55-70 year olds were tested using a double-blind cross-over design, where each participant received Sham, 2G and 3G exposures, separated by at least 4 days. RESULTS: 3-Stimulus oddball task: Behavioural: accuracy and reaction time of responses to targets were not affected by exposure. Electrophysiological: augmented N1 was found in the 2G condition (independent of age group). N-back task: Behavioural: the combined groups performed less accurately during the 3G exposure (compared to Sham), with post hoc tests finding this effect separately in the adolescents only. Electrophysiological: delayed ERD/ERS responses of the alpha power were found in both 3G and 2G conditions (compared to Sham; independent of age group). CONCLUSION: Employing tasks tailored to each individual's ability level, this study provides support for an effect of acute 2G and 3G exposure on human cognitive function. SIGNIFICANCE: The subtlety of mobile phone effect on cognition in our study suggests that it is important to account for individual differences in future mobile phone research.
Findings		Not Applicable to Bioeffects
Status		Completed With Publication
Principal Investigator		Swinburn U and Monash U, Australia - rcroft@swin.edu.au
Funding Agency		NHMRC, Australia
Country		AUSTRALIA
References		Inyang, I et al. J Paediatr Child Health., (2010) 46:226-233 Inyang, I et al. Occup Environ Med., (2010) 67:507-512 Inyang, I et al. BMC Med Res Methodol., (2009) 9:36-(9 pages) Thomas, S et al. Occup Environ Med., (2010) 67:861-866 Redmayne, M et al. J Environ Monit., (2010) 12:809-812 Leung, S et al. Clin Neurophysiol., (2011) 122:2203-2216
Comments