TNO study TNO study –– design & resultsdesign & results

Eric van Eric van RongenRongen

WHO International EMF Project IAC meetingWHO International EMF Project IAC meeting

Istanbul, 7Istanbul, 7--8 June 20048 June 2004

Study populationStudy population

•• in the Netherlands exists the in the Netherlands exists the Monitoring Monitoring Network on Health and EnvironmentNetwork on Health and Environment

•• nonnon--profitprofit, non, non--governmental volunteer governmental volunteer organisationorganisation

•• registry of people with complaints they attribute registry of people with complaints they attribute to living near (base station) antennas to living near (base station) antennas interesting study populationinteresting study population

ExposureExposure

•• initial idea: exposure to GSM initial idea: exposure to GSM cellphonecellphone--like like fieldsfields

•• ““sensitivesensitive”” subjects, therefore:subjects, therefore:basebase--stationstation--like field strengthlike field strength

Study Study goalgoal

•• determinedetermine causal relation between causal relation between EMF EMF exposureexposure and and subjective symptomssubjective symptoms

•• assess cognitiveassess cognitive performance performance during during EMF EMF exposureexposure

Experimental Experimental designdesign

•• exposureexposure in in shielded (anechoic)shielded (anechoic) roomroom•• conditionsconditions::

–– 900 MHz GSM900 MHz GSM--fieldsfields–– 1800 MHz GSM1800 MHz GSM--fieldsfields–– 2100 MHz UMTS2100 MHz UMTS--like fieldslike fields–– shamsham

•• 4 sessions of max 45 min, ~30 min interval:4 sessions of max 45 min, ~30 min interval:–– 1st: training session (no exposure)1st: training session (no exposure)–– 2nd2nd--4th: exposure sessions, randomized4th: exposure sessions, randomized

•• 1 sham1 sham•• 2 actual exposure2 actual exposure

Experimental setupExperimental setup

1,5 m

anechoic room

3 mantenna

HP E4433B

signal generator

control computer

amplifier

monitorprobe TFT

monitor

TaskomatCK8

UMTSUMTS GSMGSM

monitoring probemonitoring probe

AntennaAntenna

Taskomat setupTaskomat setup

Exposure conditionsExposure conditions

•• field strengths chosen: maximum value field strengths chosen: maximum value measured occasionally in living environment measured occasionally in living environment (1 V/m)(1 V/m)

•• peak field strength is maximizedpeak field strength is maximized•• effective field strength:effective field strength:

–– GSM: 1.0 V/mGSM: 1.0 V/m–– UMTS: 0.7 V/mUMTS: 0.7 V/m

SubjectsSubjects

•• Volunteers with subjective complaints (36; Volunteers with subjective complaints (36; group A)group A)–– recruited through Monitoring Network on Health and recruited through Monitoring Network on Health and

Environment Environment –– very reluctant to participatevery reluctant to participate

•• Volunteers without complaints (36; group B)Volunteers without complaints (36; group B)–– own TNO networkown TNO network–– local newspaper local newspaper –– InternetInternet

•• Result: unbalanced groupsResult: unbalanced groups

Subjects (cont.)Subjects (cont.)

•• 1818 –– 75 y75 y•• no historyno history ofof brain injurybrain injury, , epilepsyepilepsy, ,

claustrophobiaclaustrophobia•• not treated fornot treated for mental disease mental disease in past 6 in past 6 monthsmonths•• not treated with psychonot treated with psycho--activeactive drugs in past 2 drugs in past 2

weeksweeks•• no pacemaker or hearing aidno pacemaker or hearing aid•• no coffee / tea 6 h before start of studyno coffee / tea 6 h before start of study

Protocol Protocol -- questionnairesquestionnaires

•• questionnaire before test sessionquestionnaire before test session–– Big 5 (personality)Big 5 (personality)

•• wellwell--being: questionnaire before being: questionnaire before & & after after sessionssessions–– subset from Bulpitt questionnairesubset from Bulpitt questionnaire

•• full questionnaire validated for hypertensionfull questionnaire validated for hypertension•• contains for present study irrelevant questionscontains for present study irrelevant questions•• Ethical Committee demanded use of subsetEthical Committee demanded use of subset

Protocol Protocol –– cogn. functionscogn. functions

•• cognitive function tests:cognitive function tests:–– simple reaction timesimple reaction time–– memory taskmemory task–– visual selective attention taskvisual selective attention task–– auditive selective function taskauditive selective function task–– tracking tasktracking task

HypothesisHypothesis

•• there is no statistically significant difference in there is no statistically significant difference in subjective symptoms and cognitive functions subjective symptoms and cognitive functions between sham exposure and GSM 900, GSM between sham exposure and GSM 900, GSM 1800 or UMTS1800 or UMTS--like exposure like exposure

WellWell--being: sumscoresbeing: sumscores

0

2

4

6

8

10

12

14

Mea

n su

msc

ore

+ SE

M

S E S E S E S E S E S E

p=0.0132

p=0.0025Correction for multiplecomparisons: α=0.017

900900 18001800 21002100

GroupGroup AA

900900 18001800 21002100

GroupGroup BB

Overview of cognitive function testsOverview of cognitive function tests

Group A Group B

GSM900 GSM1800 UMTS-like GSM900 GSM1800 UMTS-like

Cognitive function test

Reaction time 0.014 0.55 0.44 0.49 0.42 0.36

Memory comparison 0.90 0.52 0.79 0.061 0.26 0.0034

Visual selective attention 0.55 0.69 0.046 0.081 0.84 0.049

Dual tasking, reaction time 0.60 0.82 0.56 0.80 0.041 0.27

Filtering irrelevant information 0.037 0.46 0.68 0.53 0.75 0.44

No correction for multiplecomparisons: α = 0.05

Correction for multiplecomparisons, (correlation0.4): α = 0.01

Mechanism?Mechanism?

•• cognitive functionscognitive functions–– other studies have found similar results for other studies have found similar results for

exposure using hand heldsexposure using hand helds–– statistically significant changes in cognitive statistically significant changes in cognitive

functions were attributed to thermal effects functions were attributed to thermal effects that might occur locallythat might occur locally

•• wellwell--being: no positive responses reported sofarbeing: no positive responses reported sofar•• questionquestion: :

–– can thermal effects explain present results?can thermal effects explain present results?

2100 MHz, side illumination2100 MHz, side illumination

0 20 40 60 80z #voxels

0

20

40

60

80

100

y#voxels

0.000

SAR[mW/kg]

x=79 0.078

CalculationsCalculations

SAR for plane wave exposure with 1 V/m

Frequency (MHz) Exposure Local SAR (mW/kg) Total SAR (nW/kg)

900 Side 0.045 0.513

1800 Side 0.082 0.383

2100 Side 0.064 0.327

2100 Front 0.078 0.316

* Average over 10 g tissue

Mechanism?Mechanism?

•• effects are highly unlikely to be caused by effects are highly unlikely to be caused by thermal effectsthermal effects

Validity questionnaireValidity questionnaire

•• original Bulpitt questionnaire validated for longoriginal Bulpitt questionnaire validated for long--term effects in hypertension studyterm effects in hypertension study

•• questionquestion: : –– is presently used subset valid for shortis presently used subset valid for short--term term

effects of EM fields?effects of EM fields?•• no answer possible without further studyno answer possible without further study

ConclusionsConclusions

•• null hypothesis (null hypothesis (““no relationno relation””) is rejected) is rejected•• statistically significant relations are found statistically significant relations are found

between RFbetween RF--exposure and measured exposure and measured parametersparameters

•• consistent effect only on wellconsistent effect only on well--beingbeing•• validity of questionnaire questionable: should validity of questionnaire questionable: should

be checkedbe checked•• thermal effects seem highly unlikely to explain thermal effects seem highly unlikely to explain

resultsresults

Conclusions (cont.)Conclusions (cont.)

•• WHO definition of health includes wellWHO definition of health includes well--being: being: effect on welleffect on well--being = effect on health being = effect on health

•• present study: the first one with this setuppresent study: the first one with this setup•• replication necessaryreplication necessary

–– Swiss group will replicate (UMTS, 1 & 10 Swiss group will replicate (UMTS, 1 & 10 V/m)V/m)

•• followfollow--up studies necessaryup studies necessary–– many parameters can be variedmany parameters can be varied–– study design can be improvedstudy design can be improved

WellWell--being questionnairebeing questionnaire

•• Questions (first 10 out of 23)Questions (first 10 out of 23)–– Feeling dizzy or faintFeeling dizzy or faint–– Feeling tired or a lack of energyFeeling tired or a lack of energy–– NervousNervous–– Feelings of pressure or tightness in head or bodyFeelings of pressure or tightness in head or body–– Scared or frightenedScared or frightened–– Heart beating quickly or strongly without reason (throbbing or Heart beating quickly or strongly without reason (throbbing or

pounding)pounding)–– Feeling that there was no hopeFeeling that there was no hope–– Restless or jumpyRestless or jumpy–– Poor memoryPoor memory–– Chest pains or breathing difficulties or feeling of not having eChest pains or breathing difficulties or feeling of not having enough nough

airair

WellWell--being questionnaire being questionnaire (cont.)(cont.)

•• answers possibleanswers possible–– not at allnot at all score: 0score: 0–– a little, slightlya little, slightly score: 1score: 1–– a great deal, quite a bita great deal, quite a bit score: 2score: 2–– extremely, could not have extremely, could not have

been worsebeen worse score: 3score: 3

WellWell--being: individual questions gr. Abeing: individual questions gr. A

Mean scores of individual questions of well-being questionnaireGroup A

0,0

0,2

0,4

0,6

0,8

1,0

Q1 Q2 Q3 Q4 Q5 Q6 Q7 Q8 Q9 Q10 Q11 Q12 Q13 Q14 Q15 Q16 Q17 Q18 Q19 Q20 Q21 Q22 Q23Question

Mea

n sc

ore

Placebo 900MHz 1800MHz 2100MHz

*

**

*

*

* *

* p<0.05

*

WellWell--being: individual questions gr. Bbeing: individual questions gr. B

Mean scores of individual questions of well-being questionnaire Group B

0,0

0,2

0,4

0,6

0,8

1,0

Q1 Q2 Q3 Q4 Q5 Q6 Q7 Q8 Q9 Q10 Q11 Q12 Q13 Q14 Q15 Q16 Q17 Q18 Q19 Q20 Q21 Q22 Q23Question

Mea

n sc

ore

Placebo 900MHz 1800MHz 2100MHz

*

* p<0.05