Bioelectromagnetics 28:309^315 (2007)

Mobile Phone Ownership and Use AmongSchool Children inThree Hungarian Cities

Gabor Mezei,1* Maria Benyi,2 and Agnes Muller3

1Electric PowerResearch Institute, PaloAlto, California2National Center for Public Health, Budapest, Hungary

3Faculty of Health Sciences, University of Pecs, Pecs, Hungary

In spite of rapid worldwide increase in mobile phone use and public concerns about associatedpotential health effects, little is known about patterns ofmobile phone ownership and use in the generalpopulation and among children. In April 2005, we conducted a survey ofmobile phone ownership anduse among fourth grade school children in three Hungarian cities. From 24 schools, 1301 student filledout a short, self-administered questionnaire on basic demographics, mobile phone ownership, patternof mobile phone use, and after-school activities. Overall, 989 students (76%) owned a mobile phone.Three hundred thirteen students (24%) used a mobile phone daily to make phone calls, and anadditional 427 students (33%) used mobile phones for phone calls at least several times per week.Sixty-six students (5%) sent text messages daily and an additional 308 students (24%) sent textmessages at least several times per week. Girls, children with no siblings, children whowere membersof a sport club, and childrenwho played computer games dailyweremore likely to own and usemobilephones regularly. A higher number of socially disadvantaged children in a class predicted lowerlikelihood of regular mobile phone use among children. Our results suggest that mobile phoneownership and regular use is highly prevalent among school children inHungary. Due to rapid changesin ownership patterns follow up surveys will be required to obtain information on temporal trends andchanges in mobile phone ownership and pattern of use among school children. Bioelectromagnetics28:309–315, 2007. � 2007 Wiley-Liss, Inc.

Key words: radiofrequency; electromagnetic fields; survey; schools; exposure; cell phone

INTRODUCTION

Mobile phone use is rapidly increasing world-wide. Hungary is no exception. According to theNational Communications Authority, mobile phonepenetration rate (the number of subscriptions per 100people) was 88% in Hungary in April 2005 [NCA,2005]. With the increase in mobile phone use, potentialhealth concerns related to mobile phones continue tosurface. Expert reviews generally conclude that thecurrently available scientific evidence is not sufficientto draw firm conclusions on potential health effectsrelated to mobile phones [IEGMP, 2000; Ahlbom et al.,2004]. Although no conclusive evidence connectsmobile phones to specific adverse health effects, specialattention is given to potential adverse health effectsamong children due to potentially increased vulner-ability of children to radiofrequency exposures and theexpectedmuch longer duration of exposure during theirlifetime [Kheifets et al., 2005]. Similar to adults, a rapidincrease in mobile phone use among children is alsolikely. Little is known, however, about the pattern ofmobile phone use among children. A recent reportdescribed the pattern ofmobile phone use and identified

predictors of regular use among fourth grade elemen-tary school children inGermany, an oldmember state ofthe European Union [Bohler and Schuz, 2004]. Wecarried out a similar survey among fourth gradeelementary school children in Hungary to obtaincomparable information on mobile phone ownershipand use among children in a new European Unionmember state.

METHODS

We completed our survey in the cities of Pecs,Bekescsaba, and Szekszard, the respective capitalsof Baranya, Bekes, and Tolna counties of Hungary.

�2007Wiley-Liss, Inc.

——————*Correspondence to: Gabor Mezei, Electric Power ResearchInstitute, 3420 Hillview Avenue, Palo Alto, CA 94304.E-mail: gmezei@epri.com

Received for review 22 December 2005; Final revision received15 March 2006

DOI 10.1002/bem.20270Published online 10 January 2007 in Wiley InterScience(www.interscience.wiley.com).

The population size of the three cities is approximately170 000, 67 000, and 37 000, respectively. Before thesurvey, permission was requested from school author-ities and parent-teacher associations. Introductoryletters were mailed to each principal of all 49 schoolsin the three cities (29 schools in Pecs, 14 schools inBekescsaba, and 6 schools in Szekszard). In the letters,we explained the purpose of the study, requested theschools’ participation in the survey, and requestedinformation on the number of fourth grade students inthe schools. If the school principal agreed to participatethen we mailed the sufficient number of questionnairesto the school. Altogether fourth grade students from24 schools participated in our survey (15 schools inPecs, 6 schools in Bekescsaba, and 3 schools inSzekszard). We noted no systematic differencesbetween participating and nonparticipating schoolswith respect to location of schools within the cities orsize of student enrollment of the schools.

We used the same questionnaires previously usedby the German investigators [Bohler and Schuz, 2004].We onlymademinor changes to adapt the questionnaireto the Hungarian language and environment and toinclude information on text messaging. The question-naires were filled out by the students under the teachers’supervision. The questionnaires asked about basicdemographics, mobile phone ownership, pattern ofmobile phone use, and after-school activities. Inaddition to the students, the teachers in each class alsofilled out a short questionnaire about the number ofchildren in the class, the estimated number of sociallydisadvantaged children in the class, and the attentionlevel of the class during the administration of thequestionnaire. Teachers were also asked about theirattitude toward mobile phone use by the students;whether they thought mobile phone use was useful orwhether it created any problem in the school. Allquestionnaireswere administered inApril 2005. Simplecross tabulation, chi-square tests and logistic regressionmodeling with forward variable selection were used toanalyze the data. SAS Statistical Software v6.12 wasused to conduct the analyses.

RESULTS

The 24 participating schools had 1389 enrolledfourth grade students at the time of the survey. Onethousand three hundred twenty-eight student question-naires were returned. In one school there were 4 and inanother school there were 14 fourth grade students; inthe remaining 22 schools the number of fourth gradestudents ranged from 20 to 90. Twenty-seven ques-tionnaires were excluded because they were not filledout leaving 1301 questionnaires for the analyses

(93.7%). Ninety-seven percent of the participatingstudents were either 10 or 11 years old (Table 1). Therewere slightly more boys (51%) than girls (49%) amongthe students.

Overall, 989 students (76%) owned a mobilephone. Most of the students received their mobilephones within the same (n¼ 333, 26%) or previousschool years (n¼ 373, 29%), and 197 (15%), 72 (6%),and 14 (1%) received their mobile phones 2, 3, or 4years earlier. Figure 1 shows the prevalence of mobilephone ownership among the students by school year andcompares it to the prevalence of mobile phone owner-ship reported fromGermany [Bohler and Schuz, 2004].Three hundred thirteen students (24%) used theirmobile phones daily to make phone calls, and anadditional 427 students (33%) used their mobile phonefor phone calls at least several times per week. Sixty-sixstudents (5%) sent textmessages daily and an additional308 students (24%) sent text messages at least severaltimes per week.

Age was not associated with mobile phoneownership or regular use (defined as use of the mobilephone at least several times per week). Girls, comparedto boys, were more likely to own and regularly usemobile phones for bothmaking phone calls and sendingtext messages. Having no siblings was also associatedwith higher likelihood of mobile phone ownership andregular use. Strong relationship was seen betweenmobile phone ownership and regular mobile phone useand duration of time spent watching television andplaying computer games. Being a member in a sportclub was also associated with higher rate of mobilephone ownership and regular use. Mode of trans-portation from school to home and usual time to go tobed were associated with regular mobile phone use, butnot with mobile phone ownership.

Students in Pecs were more likely than students inBekescsaba and Szekszard to ownmobile phones and toregularly make mobile phone calls (Table 2). Nodifferences were observed, however, in the frequencyof regular textmessaging among students from the threecities. Teachers’ attitude was not related the frequencyof mobile phone ownership and regular mobile phoneuse among their students.

We used multiple logistic regression models withforward variable selection to identify independentpredictors for mobile phone ownership, regular mobilephone use for calls, and regular text messaging(Table 3). Based on the final models, boys were lesslikely than girls to own or regularly use mobile phonesfor calls or text messaging, while being a member in asport club predicted significantly higher likelihood ofmobile phone ownership, and regular mobile phone usefor both calls and text messages. Playing computer

310 Mezei et al.

TABLE 1. Mobile Phone Ownership, Regular Mobile Phone use, and Regular Text Messagingby Student Characteristics Among Fourth Grade School Children in Three Cities (Pecs,Bekescsaba, Szekszard) in Hungary

Total number (%)b

of children incategory

Mobile phoneowners

Regulara mobilephone calls

Regulara textmessaging

n (%) n (%) n (%)

Total 1301 (100%) 989 (76.0) 740 (56.9) 374 (28.7)Age (in years)9 21 (1.6%) 16 (76.2) 8 (38.1) 2 (9.5)10 899 (69.1%) 682 (75.9) 505 (56.2) 249 (27.7)11 358 (27.5%) 273 (76.3) 217 (60.6) 115 (32.1)12 23 (1.8%) 18 (78.3) 10 (43.5) 8 (34.8)

P¼.99 P¼.07 P¼.08SexGirls 639 (49.1%) 505 (79.0) 387 (60.6) 202 (31.6)Boys 662 (50.9%) 484 (73.1) 353 (53.3) 172 (26.0)

P¼.01 P¼.008 P¼.03SiblingsNo 266 (20.4%) 218 (82.0) 174 (65.4) 85 (32.0)Yes 1035 (79.6%) 771 (74.5) 566 (54.7) 289 (27.9)

P¼.01 P¼.002 P¼.20Older siblingsNo 623 (47.9%) 492 (79.0) 376 (60.4) 183 (29.4)Yes 678 (52.1%) 497 (73.3) 364 (53.7) 191 (28.2)

P¼.02 P¼.02 P¼.63OverweightNo 1193 (91.7%) 906 (75.9) 678 (56.8) 344 (28.8)Yes 72 (5.5%) 52 (72.2) 38 (52.8) 20 (27.8)

P¼.47 P¼.50 P¼.85Time watching TVDaily >3 h 506 (38.9%) 393 (77.7) 309 (61.1) 163 (32.2)Daily <3 h 616 (47.3%) 467 (75.8) 353 (57.3) 174 (28.3)Several times/week

128 (9.8%) 94 (73.4) 61 (47.7) 30 (23.4)

Seldom 47 (3.6%) 33 (70.2) 15 (31.9) 6 (12.8)Never 2 (0.2%) 0 (0) 0 (0) 0 (0)

P¼.08 P¼.001 P¼.02Time playing computer gamesDaily >3 h 206 (15.8%) 159 (77.2) 133 (64.4) 79 (38.4)Daily <3 h 300 (23.1%) 243 (81.0) 198 (66.0) 95 (31.7)Several times/week

423 (32.5%) 307 (72.6) 224 (53.0) 117 (27.7)

Seldom 286 (22.0%) 222 (77.6) 145 (50.7) 58 (20.3)Never 84 (6.5%) 56 (66.7) 39 (46.4) 24 (28.6)

P¼.02 P¼.001 P¼.001SportsNo 344 (26.4%) 245 (71.2) 153 (44.5) 75 (21.8)Yes 950 (73.0%) 739 (77.8) 584 (61.5) 295 (31.1)

P¼.01 P¼.001 P¼.001Time to home>30 min 242 (18.6%) 192 (79.3) 131 (54.1) 70 (28.9)10–30 min 517 (39.7%) 400 (77.4) 296 (57.3) 146 (28.2)<10 min 423 (32.5%) 310 (73.3) 243 (57.5) 121 (28.6)Not goinghome directly

116 (8.9%) 84 (72.4) 70 (60.3) 36 (31.0)

P¼.21 P¼.71 P¼.95Transportation to homeOn foot 557 (42.8%) 409 (73.4) 308 (55.3) 152 (27.3)Bike 67 (5.1%) 51 (76.1) 37 (55.2) 25 (37.3)Bus 311 (23.9%) 236 (75.9) 162 (52.1) 72 (23.2)Car 303 (23.3%) 244 (80.5) 189 (62.4) 105 (34.7)

P¼.23 P¼.01 P¼.01

(Continued)

Mobile Phones and School Children 311

games daily was also a strong predictor for mobilephone ownership and regular use of mobile phone formaking calls and sending text messages. Having anolder sibling predicted lower likelihood of mobilephone ownership and mobile phone use for makingcalls, but not for sending text messages. Older studentsand students who went home by car after school,however, were more likely to send text messagesregularly. Going to bed later at night was also apredictor of regular mobile phone use for calls and textmessaging. Compared to students in Pecs, students inBekescsaba and Szekszard were less likely to ownmobile phones or use mobile phones for calls. Finally,having ten or more socially disadvantaged children inthe same class predicted lower likelihood of makingregular mobile phone calls.

DISCUSSION

This is the first report on mobile phone ownershipand pattern of use among school children in Hungary orin any other Central and Eastern European countries.Our results suggest high prevalence of mobile phoneownership (76%) among Hungarian fourth gradestudents. We also found that high proportion of thestudents (57%) used mobile phones regularly (at leastseveral times per week) for making phone calls, andsmaller fraction of students (29%) used mobile phonesregularly for text messaging. The prevalence of own-ership among Hungarian students was more thantwofold higher than that among German students (76vs. 35%), and the frequency of regular phone use amongHungarian children was more than fourfold higher than

TABLE 1. (Continued)

Total number (%)b

of children incategory

Mobile phoneowners

Regulara mobilephone calls

Regulara textmessaging

n (%) n (%) n (%)

Bedtime<8 PM 75 (5.8%) 52 (69.3) 36 (48.0) 14 (18.7)8–9 PM 531 (40.8%) 387 (72.9) 248 (46.7) 135 (25.4)9–10 PM 525 (40.4%) 414 (78.9) 347 (66.1) 160 (30.5)10–11 PM 129 (9.9%) 105 (81.4) 82 (63.6) 42 (32.6)>11 PM 39 (3.0%) 29 (74.4) 26 (66.7) 21 (53.9)

P¼.06 P¼.001 P¼.001

aRegular use is defined as use of the mobile phone at least several times per week.bDue to some missing values the totals do not always add up to 1301 (100%).

0

10

20

30

40

50

60

70

80

2004-20052003-20042002-20032001-20022000-20011999-2000

School year

Per

cen

t o

f ch

ildre

n w

ith

cel

l ph

on

e

German Fourth Grade Students (2002-2003)

Hungarian Fourth Grade Students (2004-2005)

Fig. 1. Prevalence of mobile phone ownership in the Hungarian and German [Bohler and Schuz,2004] surveysbyschoolyear.

312 Mezei et al.

that among German children (57 vs. 13%) [Bohler andSchuz, 2004]. These differences are most likely to beexplained by the difference in calendar time betweenthe administrations of the two surveys. The Germansurvey was completed in November 2002 and February2003, our survey in Hungary was conducted morethan 2 years later in April 2005. Since during this morethan 2 year period mobile phone penetration rate rosefrom less than 70% to close to 90% inHungary andmostof the children in our survey (71% of mobile phoneowners) received their mobile phones within the last2 years, it is likely that the observed differences reflecttemporal trends rather than differences between the twocountries. Data presented in Figure 1, which shows

steadily increasing mobile phone ownership amongparticipating students in both countries, but higherprevalence among the German students comparedto Hungarian students during specific school years,also supports the argument that the differences aremorelikely due to changes over time.

With respect to independent predictors of mobilephone ownership and regular mobile phone use, someof our results were similar to the results of the Germanstudy. Like in Germany, children without siblings,childrenwhoweremembers of sport clubs, and childrenwho played computer games daily were more likely tobe mobile phone owners or regular mobile phone usersinHungary, aswell.We also observed that childrenwho

TABLE 2. Mobile Phone Ownership, Regular Mobile Phone Use, and Regular Text Messagingby Class Characteristics and Teachers’ Opinion Among Fourth Grade School Children inThree Cities (Pecs, Bekescsaba, Szekszard) in Hungary

Total number(%)b of children

in category

Mobile phoneowners

Regulara

mobile phonecalls

Regulara textmessaging

n (%) n (%) n (%)

CityPecs 802 (61.6%) 638 (79.6) 479 (59.7) 230 (28.7)Bekescsaba 320 (24.6%) 227 (70.9) 165 (51.6) 87 (27.2)Szekszard 179 (13.8%) 124 (69.3) 96 (53.6) 57 (31.8)

P¼.001 P¼.03 P¼.54Number of students/class<15 37 (2.8%) 21 (56.8) 19 (51.4) 8 (21.6)15–25 742 (57.0%) 556 (74.9) 409 (55.1) 191 (25.7)>25 486 (37.3%) 382 (78.6) 293 (60.3) 167 (34.4)

P¼.008 P¼.16 P¼.003AttentionVery good 331 (25.4%) 231 (69.8) 173 (52.3) 85 (25.7)Good 742 (57.0%) 579 (78.0) 437 (58.9) 227 (30.6)Fair 164 (12.6%) 123 (75.0) 91 (55.5) 48 (29.3)Poor 26 (2.0%) 22 (84.6) 17 (65.4) 4 (15.4)

P¼.02 P¼.17 P¼.17Socially disadvantaged in class0–4 638 (49.0%) 483 (75.7) 379 (59.4) 188 (29.5)5–9 556 (42.7%) 422 (75.9) 311 (55.9) 160 (28.8)10–14 69 (5.3%) 53 (76.8) 33 (47.8) 17 (24.6)>14 20 (1.5%) 14 (70.0) 9 (45.0) 4 (20.0)

P¼.94 P¼.15 P¼.69Teacher’s attitude: cell phone usefulYes 326 (25.1%) 254 (77.9) 190 (58.3) 99 (30.4)No 832 (64.0%) 625 (75.1) 458 (55.1) 228 (27.4)No opinion 143 (11.0%) 110 (76.9) 92 (64.3) 47 (32.9)

P¼.58 P¼.10 P¼.31Teacher’s attitude: cell phone problemYes, causes social tension 593 (45.6%) 454 (76.6) 331 (55.8) 178 (30.0)Yes, disturbs class 329 (25.3%) 250 (76.0) 186 (56.5) 86 (26.1)No problem 298 (22.9%) 223 (74.8) 173 (58.1) 88 (29.5)No opinion 81 (6.2%) 62 (76.5) 50 (61.7) 22 (27.2)

P¼.95 P¼.75 P¼.63

aRegular use is defined as use of the mobile phone at least several times per week.bDue to some missing values the totals do not always add up to 1301 (100%).

Mobile Phones and School Children 313

go to bed later are more likely to use mobile phonesregularly. In our survey, going home from school by carand age of the student were independent predictors onlyfor regular text messaging. Unlike in Germany,however, boys compared to girls were less likely toown or regularly use mobile phones in Hungary.Increasing number of socially disadvantaged childrenin the class predicted less frequent regularmobile phoneuse inHungary, as opposed tomore frequent regular usein Germany. The opposite trends observed in GermanyandHungary in relation to socioeconomic statusmay beexplained by the lower average family income inHungary.Mobile phone ownership and usemay presenta relatively bigger financial burden in low-income

families in a country with lower average income. Wealso observed significant differences in mobile phoneownership and regular use by city of residence amongthe children in our survey. Compared to students inPecs, students in Bekescsaba and Szekszard were lesslikely to own or regularly use mobile phones. Thesespatial differences may be explained by the differentlevels of economic development of the three cities.

The main limitation of our survey is the lowparticipation rate of schools; we were able to includeabout half of the schools in the three cities in our study.In principle, it may results in substantial selection bias,that is, over- or underestimation of the true prevalenceof mobile phone ownership and regular mobile phone

TABLE 3. Independent Predictors of Mobile Phone Ownership, Regular Mobile Phone use, and Regular Text Messaging AmongFourth Grade School Children in Three Cities (Pecs, Bekescsaba, Szekszard) in Hungary

Mobile phone owners Regulara mobile phone calls Regulara text messaging

Odds ratio95% confidence

interval Odds ratio95% confidence

interval Odds ratio95% confidence

interval

Age (in years) — — — — 1.32 1.04, 1.67SexGirls 1.00 Reference 1.00 Reference 1.00 ReferenceBoys .61 .46, .81 .51 .40, .67 .53 .40, .70

Older siblingNo 1.00 Reference 1.00 Reference — —Yes .70 .54, .91 .65 .51, .82 — —

Time playing computer gamesSeldom or never 1.00 Reference 1.00 Reference 1.00 ReferenceSeveral times/week .97 .70, 1.35 1.21 .90, 1.64 1.47 1.05, 2.06Daily <3 h 1.72 1.16, 2.55 2.23 1.56, 3.17 1.99 1.37, 2.90Daily >3 h 1.57 1.01, 2.45 2.37 1.55, 3.61 2.64 1.70, 4.08

SportsNo 1.00 Reference 1.00 Reference 1.00 ReferenceYes 1.44 1.08, 1.91 2.10 1.62, 2.74 1.64 1.22, 2.21

Transportation to homeOn foot — — — — 1.00 ReferenceBike — — — — 1.67 .96, 2.88Bus — — — — .83 .60, 1.15Car — — — — 1.52 1.12, 2.06

Bedtime<8 PM — — 1.00 Reference 1.00 Reference8–9 PM — — .88 .53, 1.46 1.26 .68, 2.329–10 PM — — 1.89 1.13, 3.17 1.51 .82, 2.7710–11 PM — — 1.70 .92, 3.14 1.58 .78, 3.17>11 PM — — 2.09 .88, 4.98 3.61 1.48, 8.80

CityPecs 1.00 Reference 1.00 Reference — —Bekescsaba .64 .48, .87 .66 .49, .89 — —Szekszard .58 .40, .84 .66 .46, .93 — —

Socially disadvantaged in class0–4 — — 1.00 Reference — —5–9 — — .98 .75, 1.26 — —>9 — — .53 .33, .86 — —

aRegular use is defined as use of the mobile phone at least several times per week.

314 Mezei et al.

use among Hungarian school children. However,we noted no systematic differences in geographiclocation of schools within the cities or size of studentenrollment of the schools between participating andnonparticipating schools which provide some reassur-ance that no gross bias is present in our study. Theobserved range of prevalence of mobile phone owner-ship in the 23 schools with at least 14 fourth gradestudents were 65–89%which also suggests that schoolsdo not vary from each other in an extreme degree.

In conclusion, we provide the first report onmobile phone ownership and pattern of use amongschool children in Hungary. Overall, we observed highprevalence of mobile phone ownership, and highfrequency of regular use amongHungarian fourth gradestudents. Due to rapid changes in ownership patternsfollow up surveyswill be required to obtain informationon temporal trends and changes in mobile phone

ownership and pattern of mobile phone use amongschool children in Hungary.

REFERENCES

Ahlbom A, Green A, Kheifets L, Savitz D, Swerdlow A. 2004.Epidemiology of health effects of radiofrequency exposure.Environ Health Perspect 112:1741–1754.

Bohler E, Schuz J. 2004. Cellular telephone use among primaryschool children in Germany. Eur J Epidemiol 19:1043–1050.

Independent Expert Group on Mobile Phones (IEGMP). 2000.The Stewart Report. Mobile phone and health. Chilton,UnitedKingdom. (http://www.iegmp.org.uk/report/text.htm,accessed October 25, 2005).

Kheifets L, Repacholi M, Saunders R, van Deventer E. 2005. Thesensitivity of children to electromagnetic fields. Pediatrics116:303–313.

National Communications Authority (NCA). 2005. Digital mobilephone market report, April 2005. Budapest, Hungary.(http://www.nhh.hu/english/menu3/m3_2/mobil/2005/april.pdf, accessed October 25, 2005).

Mobile Phones and School Children 315