27.11.2007 Patrizia Frei, MSc

QUALIFEXHealth related quality of life and radio frequency electromagnetic field exposure: Prospective cohort study

27.11.2007Patrizia Frei, MScDepartment of Social and Preventive Medicine, University of Bern, Switzerland

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The electromagnetic Spectrum

Static EMF

Low frequency

EMF

Radio frequency

EMF

Infra-red

Light UV Ionizing Radiation

Electromagnetic Fields(EMF)

Optical Radiation

Non-ionizing Radiation (NIS)

>Radio frequency electromagnetic fields (RF EMF)

Basics (1)

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Basics (2)

> Radio frequency electromagnetic fields (RF EMF):— Radio transmitters— Television transmitters— Tetrapol (radio communication for authorities)— Mobile phones (GSM and UMTS) — Mobile phone base stations (GSM and UMTS)— Cordless phones (DECT)— Wireless LAN

> Non-specific symptoms that are frequently attributed to RF EMF:— headache — dizziness — tiredness— discomfort— itching skin — sleep disorder

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QUALIFEX: Study Overview

Exposimeter Study:

• Measurements with exposimeter• Diary• Questionnaire on exposure

200 participants

Main Study:

• Questionnaire on expo- sure and health • Follow-up after one year

2000 participants

Sleep Study:

• Measurement with Actimeter• Sleep diary

120 participants

Year 1(2007)

Years 2, 3 & 4(2008 until 2010)

Exposure assessment

method

ISEE CEEC Conference, Czech Republic, Nov 26th-29th

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QUALIFEX: Study Overview

Exposimeter Study:

• Measurements with exposimeter• Diary• Questionnaire on exposure

200 participants

Main Study:

• Questionnaire on expo- sure and health • Follow-up after one year

2000 participants

Sleep Study:

• Measurement with Actimeter• Sleep diary

120 participants

Year 1(2007)

Years 2, 3 & 4(2008 until 2010)

Exposure assessment

method

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Study area

Exposimeter

Exposimeter study

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Exposimeter study: Statistical methods

> Summary statistics:— Median and interquartile range

> Statistical analysis:— Significance test of group difference:

Wilcoxon rank-sum (Mann-Whitney) test— Level of significance:

* 0.01 < p < 0.05** 0.001 < p < 0.01 *** p < 0.001

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Preliminary results (1): example of a daily exposure pattern

bedroom

traincall with cordless phonestation

tram

train

WLANoffice

lunch break

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Preliminary results (2): Results from the first 140 study participants

> Median exposure over one week:0.20 V/m (interquartile range: 0.15-0.27 V/m)

> Contributions of the different sources to the total exposure

6% 5%

0%

27%

32%

26%

4%

Radio transmitter

Television transmitter

Tetrapol

Mobile phone

Mobile phone base station

Cordless phone

Wireless LAN

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Preliminary results (3): Comparison of different groups

1. Living close to mobile phone base stations or a radio/TV transmitter (fixed transmitter)

2. Owning a cordless phone

3. Owning a mobile phone

4. Owning WLAN

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1. Living close to a fixed transmitter

n Total exposure (V/m)

Exposure to fixed transmitter (V/m)

People living close to a fixed transmitter (highly exposed group)

36 0.24 0.18

Unselected volunteers (reference group)

104 0.20 0.08

Wilcoxon rank-sum test p=0.004 p<0.0001

***

0

0.05

0.1

0.15

0.2

0.25

Radiotransmitter

Televisiontransmitter

Tetrapol Mobilephone

Mobilephone base

station

Cordlessphone

WirelessLAN

V/m

highly exposed group

reference group

*

*****

**

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2. Owning a cordless phone

n Total exposure (V/m)

Exposure to cordl. phone (V/m)

Persons owning a cordless phone 106 0.21 0.09

Persons not owning a cordl. phone 30 0.19 0.04

Wilcoxon rank-sum test p=0.127 p<0.0001

0

0.02

0.04

0.06

0.08

0.1

0.12

0.14

0.16

Radiotransmitter

Televisiontransmitter

Tetrapol Mobilephone

Mobilephone base

station

Cordlessphone

WirelessLAN

V/m

DECT

No DECT

***

*

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3. Owning a mobile phone

n Total exposure (V/m)

Exposure to mobile phone (V/m)

Persons owning a mobile phone 119 0.20 0.10

Persons not owning a mob. phone 17 0.17 0.06

Wilcoxon rank-sum test p=0.013 p=0.003

0

0.02

0.04

0.06

0.08

0.1

0.12

0.14

0.16

Radiotransmitter

Televisiontransmitter

Tetrapol Mobilephone

Mobilephone base

station

Cordlessphone

WirelessLAN

V/m

Mobile phone

No mobile phone

**

***

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4. Owning WLAN

n Total exposure (V/m)

Exposure to WLAN (V/m)

Persons owning WLAN 41 0.20 0.03

Persons not owning WLAN 92 0.20 0.02

Wilcoxon rank-sum test p=0.826 p<0.001

0

0.02

0.04

0.06

0.08

0.1

0.12

0.14

0.16

0.18

Radiotransmitter

Televisiontransmitter

Tetrapol Mobilephone

Mobilephone base

station

Cordlessphone

WirelessLAN

V/m

WLAN

No WLAN

**** *

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Conclusions and Outlook

> In our sample of 140 persons, the main contributions to the total exposure is due to mobile phones, cordless phones and mobile phone base stations

> In terms of total exposure, there are significant differences between persons living close to transmitters and those not, and between people owning a mobile phone and those not

> Further multivariable analyses are needed to investigate combined effects of all predictors (multiple linear regression model)