Recall of mobile phone usage and laterality in young people: The multinational Mobi-Expo study

doi:10.1016/j.envres.2018.04.018

Environmental Research

Volume 165, August 2018, Pages 150-157

https://doi.org/10.1016/j.envres.2018.04.018 Get rights and content

Highlights

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Large multinational study on recall of mobile phone use in young participants.
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Mobile phone use was recorded from the phone rather than from operator data.
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We observed substantial systematic and random errors in recall.
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Results can be used as input for future studies and RF exposure modelling.

Abstract

Objective

To study recall of mobile phone usage, including laterality and hands-free use, in young people.

Methods

Actual mobile phone use was recorded among volunteers aged between 10 and 24 years from 12 countries by the software application XMobiSense and was compared with self-reported mobile phone use at 6 and 18 months after using the application. The application recorded number and duration of voice calls, number of text messages, amount of data transfer, laterality (% of call time the phone was near the right or left side of the head, or neither), and hands-free usage. After data cleaning, 466 participants were available for the main analyses (recorded vs. self-reported phone use after 6 months).

Results

Participants were on average 18.6 years old (IQR 15.2–21.8 years). The Spearman correlation coefficients between recorded and self-reported (after 6 months) number and duration of voice calls were 0.68 and 0.65, respectively. Number of calls was on average underestimated by the participants (adjusted geometric mean ratio (GMR) self-report/recorded = 0.52, 95% CI = 0.47–0.58), while duration of calls was overestimated (GMR=1.32, 95%, CI = 1.15–1.52). The ratios significantly differed by country, age, maternal educational level, and level of reported phone use, but not by time of the interview (6 vs. 18 months). Individuals who reported low mobile phone use underestimated their use, while individuals who reported the highest level of phone use were more likely to overestimate their use. Individuals who reported using the phone mainly on the right side of the head used it more on the right (71.1%) than the left (28.9%) side. Self-reported left side users, however, used the phone only slightly more on the left (53.3%) than the right (46.7%) side. Recorded percentage hands-free use (headset, speaker mode, Bluetooth) increased with increasing self-reported frequency of hands-free device usage. Frequent (≥50% of call time) reported headset or speaker mode use corresponded with 17.1% and 17.2% of total call time, respectively, that was recorded as hands-free use.

Discussion

These results indicate that young people can recall phone use moderately well, with recall depending on the amount of phone use and participants’ characteristics. The obtained information can be used to calibrate self-reported mobile use to improve estimation of radiofrequency exposure from mobile phones.

Introduction

The rapid worldwide increase in mobile phone use has led to increased concern about potential health effects due to exposure to radiofrequency (RF) fields. Additionally, mobile phone use has changed dramatically in recent years with both the introduction of third and fourth generation cellular networks as well as continuously evolving smartphone hardware and software. Potential health effects (if they exist) related to RF fields originating from mobile phones would likely be greater among young people for various reasons. The neurological system of children is still developing and may be more sensitive to effects of RF, the distribution of RF absorption across the brain may be different compared to adults, and the specific absorption rate (SAR) in the most exposed part of the brain tend to be higher in children than it is in adults (Wiart et al., 2011). Lastly, the lifetime exposure of children to RF from mobile phones will be larger as they start using a mobile phone at a young age compared to current adults. Several national and international bodies have recommended studies of exposure in childhood and adolescence as high priority RF research areas due to this (Kheifets, 2005). As a result, two large multinational case-control studies were set up, the CEFALO study in four (Northern) European countries (Aydin et al., 2011c), and the MOBI-Kids study in 14 countries, both within and outside Europe (Sadetzki et al., 2014). In addition several national studies were set up, including the HERMES study in Switzerland (Schoeni et al., 2015), and the SCAMP cohort study in the United Kingdom (Mireku et al., 2018), looking at cognitive and behavioural outcomes.

Exposure assessment within epidemiological studies on health effects of mobile phone use generally relies on participants’ recall of their mobile phone use. Previous validation studies among children and adolescents have found that this recall comes with substantial random and systematic errors (Aydin et al., 2011a, Goedhart et al., 2015b, Inyang et al., 2010, Inyang et al., 2009, Kiyohara et al., 2016, Redmayne et al., 2012), which can lead to under- or overestimation of the explored health risks (Aydin et al., 2011b; Vrijheid et al., 2006a, Vrijheid et al., 2006b). As part of MOBI-Kids, a case-control study exploring the potential effects of childhood and adolescent exposure to electromagnetic fields from mobile communications technologies on brain tumour risk (Sadetzki et al., 2014), the Mobi-Expo validation study was performed to study recall of mobile phone use among young people from 12 out of 14 countries. This is the largest multinational validation study to date. A software application (app) was developed by Whist Lab (Paris, France) to be installed on participants’ own smartphone or a study phone (Goedhart et al., 2015b). In addition to duration and frequency of calls and text messages, the app also recorded information regarding laterality, hands-free usage, and data transfer. We report here the results of mobile phone usage and use behaviour recall at 6 and 18 months after the use of the app by study individuals. In addition, we explore if the observed differences in recall are related to demographic variables and/or phone usage.

Section snippets

Methods

From October 2012 to August 2014, volunteers between 10 and 24 years old were recruited in 12 MOBI-Kids countries: Australia, Canada, France, Germany, Greece, Israel, Italy, Japan, Korea, New Zealand, Spain and the Netherlands. The study was approved by the Institutional Review Boards in each country; all volunteers and/or their legal guardians provided informed consent following the country-specific protocols, including parental consent if indicated. More details about the recruitment

Results

Participants were on average 18.6 years old (interquartile range 15.2 – 21.8 years), 37% were male, and 47% of the individuals’ mothers had attained the highest level of education. The patterns in recorded mobile phone use are described in more detail by Langer et al. (2017). In summary, higher recorded call number and duration were found among females, and in the oldest age group. Age and country explained a large part of the variance in recorded phone use characteristics, with gender,

Discussion

This large, multinational study on recall in young participants compared self-reported mobile phone use with software application-recorded mobile phone use. Recall errors were found for both number and duration of voice calls, with ratios significantly differing by country, age, educational level, and level of reported phone use, but not by time of interview. Systematic errors were found, with the number of calls underestimated by a factor of 0.52 on average, and the duration of calls and

Acknowledgements

The authors thank Thierry Sarrebourse and Emannuele Conil (WHIST Lab, France) for their technical support with the software application XMobiSense. Canada (Ottawa) received support from a peer reviewed university-industry partnerships grant from the Canadian Institutes of Health Research, with the Canadian Wireless Telecommunications Association (CWTA) as the industrial partner (http://www.crealradiation.com/index.php/en/mobi-kids-financial-sources). D. Krewski holds a Natural Sciences and

Declarations of interest

Canada (Ottawa) received financial support from the Canadian Wireless Telecommunications Association under the federal university-industry research partnerships programs noted below.

The rest of the authors declare no conflict of interest.

Grant sponsors

The research leading to these results has received funding from the French Agency for Food, Environmental and Occupational Health & Safety (ANSES) under grant agreement number No. 2011/1/216 the Mobi-Expo project, the Netherlands Organisation for Health

References (21)

D. Aydin et al.
Predictors and overestimation of recalled mobile phone use among children and adolescents
Prog. Biophys. Mol. Biol.
(2011)
C.E. Langer et al.
Patterns of cellular phone use among young people in 12 countries: implications for RF exposure
Environ. Int.
(2017)
J. McCambridge et al.
Systematic review of the Hawthorne effect: new concepts are needed to study research participation effects
J. Clin. Epidemiol.
(2014)
M.O. Mireku et al.
Total recall in the SCAMP cohort: validation of self-reported mobile phone use in the smartphone era
Environ. Res.
(2018)
A. Schoeni et al.
Memory performance, wireless communication and exposure to radiofrequency electromagnetic fields: a prospective cohort study in adolescents
Environ. Int.
(2015)
J. Wiart et al.
Numerical dosimetry dedicated to children RF exposure
Prog. Biophys. Mol. Biol.
(2011)
D. Aydin et al.
Impact of random and systematic recall errors and selection bias in case-control studies on mobile phone use and brain tumors in adolescents (CEFALO study)
Bioelectromagnetics
(2011)
D. Aydin et al.
Mobile phone use and brain tumors in children and adolescents: a multicenter case-control study
J. Natl. Cancer Inst.
(2011)
E. Cardis
Brain tumour risk in relation to mobile telephone use: results of the INTERPHONE international case-control study
Int. J. Epidemiol.
(2010)
E. Cardis et al.
Distribution of RF energy emitted by mobile phones in anatomical structures of the brain
Phys. Med. Biol.
(2008)

There are more references available in the full text version of this article.

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This work builds on the INTERPHONE algorithm (Cardis et al., 2011b), by also taking into account ELF EMFs, recent improvements in dosimetry and the evolution of communication systems over the last two decades, some of which have been shown to result in differences in both RF and ELF dose by an order of magnitude or greater (Calderón et al., 2017; Wiart, 2013). Refinements were also possible as a result of the MOBI-Expo validation study, complementary to MOBI-Kids, which utilised an app to validate mobile phone use reported by young people (Goedhart et al., 2018). Doses were estimated for all mobile or cordless phone users in the study across the 14 participating countries, and a statistical analysis was performed to determine the level of agreement between dose and self-reported use of mobile phone, and between RF and ELF dose.
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Median CSE and CICD were substantially higher in GSM than 3G systems and varied considerably with location in the brain. Agreement between RF CSE and mobile phone use variables was moderate to null, depending on the communication system. Agreement between mobile phone use variables and ELF CICD was higher overall but also strongly dependent on communication system. Despite ELF dose distribution across the brain being more diffuse than that of RF, high correlation was observed between RF and ELF dose.
The algorithm was used to systematically estimate the localised RF and ELF doses in the brain from wireless phones, which were found to be strongly dependent on location and communication system. Analysis of cartographies showed high correlation across phone models and across ages, however diagonal agreement between these cartographies suggest these factors do affect dose distribution to some level. Overall, duration and number of calls may not be adequate proxies of dose, particularly as communication systems available for voice calls tend to become more complex with time.
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Wireless phone use in childhood and adolescence and neuroepithelial brain tumours: Results from the international MOBI-Kids study
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For periods when a subject reported using hands-free devices or the speaker of their mobile or cordless phone, the amount of use was reduced by 18.5%, 7% or 3.5%, depending on whether the devices were used half the time or more, less than half the time, or never or rarely. These values were determined from the results of the MOBI-Expo validation study (Goedhart et al., 2018). Similarly, if hands-free use was through a Bluetooth device, the reduction factors were 10%, 1% and 0% respectively.
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Little is known about radiofrequency electromagnetic fields (RF) from mobile technology and resulting dose in young people. We describe modeled integrated RF dose in European children and adolescents combining own mobile device use and surrounding sources.
Using an integrated RF model, we estimated the daily RF dose in the brain (whole-brain, cerebellum, frontal lobe, midbrain, occipital lobe, parietal lobe, temporal lobes) and the whole-body in 8358 children (ages 8–12) and adolescents (ages 14–18) from the Netherlands, Spain, and Switzerland during 2012–2016. The integrated model estimated RF dose from near-field sources (digital enhanced communication technology (DECT) phone, mobile phone, tablet, and laptop) and far-field sources (mobile phone base stations via 3D-radiowave modeling or RF measurements).
Adolescents were more frequent mobile phone users and experienced higher modeled RF doses in the whole-brain (median 330.4 mJ/kg/day) compared to children (median 81.8 mJ/kg/day). Children spent more time using tablets or laptops compared to adolescents, resulting in higher RF doses in the whole-body (median whole-body dose of 81.8 mJ/kg/day) compared to adolescents (41.9 mJ/kg/day). Among brain regions, temporal lobes received the highest RF dose (medians of 274.9 and 1786.5 mJ/kg/day in children and adolescents, respectively) followed by the frontal lobe. In most children and adolescents, calling on 2G networks was the main contributor to RF dose in the whole-brain (medians of 31.1 and 273.7 mJ/kg/day, respectively).
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¹: These authors contributed equally.

View full text

Recall of mobile phone usage and laterality in young people: The multinational Mobi-Expo study

Highlights

Abstract

Objective

Methods

Results

Discussion

Introduction

Section snippets

Methods

Results

Discussion

Acknowledgements

Declarations of interest

Grant sponsors

Prog. Biophys. Mol. Biol.

Environ. Int.

J. Clin. Epidemiol.

Environ. Res.

Environ. Int.

Prog. Biophys. Mol. Biol.

Impact of random and systematic recall errors and selection bias in case-control studies on mobile phone use and brain tumors in adolescents (CEFALO study)

Bioelectromagnetics

Mobile phone use and brain tumors in children and adolescents: a multicenter case-control study

J. Natl. Cancer Inst.

Brain tumour risk in relation to mobile telephone use: results of the INTERPHONE international case-control study

Int. J. Epidemiol.

Distribution of RF energy emitted by mobile phones in anatomical structures of the brain

Phys. Med. Biol.