exposure of the general public to rf electromagnetic fields · transmitters radio broadcast...

IMST GmbHCarl-Friedrich-Gauß-Strasse 2 47475 Kamp-Lintfortwww.imst.de

Tel.: +49-2842-981-0Fax: +49-2842-981-199E-Mail: [email protected]

Workshop "Acute Health Impairment", Dec 12-13, 2006

Exposure of the general public

to RF electromagnetic fields

Dr. Christian Bornkessel, IMST GmbH,

Carl-Friedrich-Gauss-St. 2, D-47475 Kamp-Lintfort

[email protected]

Folie 2

Exposure of general public, November 07

Outline

• RF sources and their exposure

- relevant exposures in everyday life

- focus on general public exposure

- exposure results with special regard to DMF studies

• Personal exposure meters (Dosimeter)

- available dosimeters

- typical results

Folie 3


Classification of relevant RF sources

Fixed Mobile

Installation type

Mobile phone

base stations

TV broadcast

transmitters

Mobile phones

Radio broadcast

transmitters

DECT phones

WLAN applications

Folie 4



Outdoor Household

Installation place

Mobile phone

base stationsMobile phones

DECT phones

WLAN applications

TV broadcast

transmitters

Radio broadcast

transmitters

Folie 5



Far fieldClose to body

or body contact

Distance

Mobile phone

base stationsMobile phones

DECT phones

WLAN applications

TV broadcast

transmitters

Radio broadcast

transmitters

Folie 6


Mobile phone base stations

Frequency: - 925 – 960 MHz (GSM 900)

- 1820 – 1880 MHz (GSM 1800)

- 2110 – 2170 MHz (UMTS)

Transmit - typ. 5-30 W/channel/sector

Power: - 100-1800 W (EIRP)/channel/sector

Transmitter: - ~85,000 stations in Germany

Coverage: - 500 m – 20 km

Distance to

Persons: - far field

Remarks: - power control

Folie 7


Projects supported within DMF

Development of measurement and calculation methods for the determination of the public

exposure due to electromagnetic fields in the

vicinity of mobile phone base stations (IMST)

Determination of the exposure of groups of people that will be investigated within the scope

of the project "Cross sectional study for ascertainment and assessment of possible

adverse effects by fields of mobile phone base

stations" (ECOLOG)

Determination of the real field distribution from high frequency electromagnetic fields near

UMTS transmitters (IMST+EM Institute)

BS

Folie 8


0,000

0,001

0,010

0,100

1,000

10,000

100,000

po

wer

den

sit

y i

n %

of

lim

it

1 2 3 4 5 6 7 8 9 10 11

GSM

UMTS

Extrapolated exposure (IMST+EM-Institute)

scenario no.

0.7 % limit5.1 V/m69.3 mW/m²

0.000001 %0.01 V/m0.1 µW/m²

1.6 % limit5.4 V/m78.3 mW/m²

0.000001 %0.004 V/m0.03 µW/m²

Folie 9


Extrapolated exposure near base stations (2)

0,000

0,001

0,010

0,100

1,000

10,000

100,000

po

wer

den

sit

y i

n %

of

lim

it

1 2 3 4 5 6 7 8 9 10 11

GSM

UMTS

scenario no.

low mounted antennas (micro cell / indoor scenarios)

low mounted antennas

high mounted antennas

Fo

lie 1

0

Exposu

re o

f gene

ral p

ublic

, Novem

be

r 07

Co

mp

aris

on

GS

M/U

MT

S

0 2 4 6 8

10

12

14

1.1

1.2

1.3

1.4

1.5

1.6

1.7

1.8

1.9

1.10

1.11

1.12

1.13

1.14

1.15

1.16

1.17

1.18

1.19

1.20

1.21

1.22

2.1

2.2

2.3

2.4

2.5

2.6

2.7

2.8

2.9

2.10

2.11

2.12

3.1

3.2

3.3

3.4

3.5

3.6

3.7

3.8

3.9

3.10

3.11

3.22

3.13

3.14

3.15

3.16

3.17

4.1

4.2

4.3

4.4

4.5

4.6

4.7

4.8

me

as

ure

me

nt p

oin

t no

.

electric field strength [% of limit]

GS

M

UM

TS

�G

SM

> U

MT

S a

t 8

5 %

of a

ll poin

ts

(co

mp

are

d to

limit)

GS

M 9

00

an

ten

na

pa

ttern

UM

TS

an

ten

na

pa

ttern

Folie 11


Small scale field variation in space

70

75

80

85

90

95

100

0 20 40 60 80 100 120 140

place [cm]

ele

ctr

ic f

ield

str

en

gth

[d

Bµ

V/m

]

GSM 900

UMTS

• Small scale variations (fast fading) especially at indoor scenarios

due to multipath propagation

• Variations of 10 dB and more

Simulation: GSM 900Measurement: GSM 900 and UMTS

Folie 12


Small and large scale variations in time

time

1

1,5

2

2,5

3

3,5

4

12:00 16:00 20:00 0:00 4:00 8:00 12:00

ele

ctr

ic f

ield

str

en

gth

[V

/m]

day

Tu We Th Fr Sa Su Mo Tu

2.0

1.8

1.6

1.4

1.2

1.0

ele

ctr

ic f

ield

str

en

gth

[V

/m]

Station A: GSM 24 hours Station B: GSM 7 days

• Small and large scale variations due to traffic load (power control)

Folie 13


Time and space averaged exposure (ECOLOG)

1 m x 1 m grid

5 point grid

• Time and space averaging, no focus on "maximal exposed areas"

� Exposure 10 - 1,000 times smaller than measured under worst case aspects

Exposure inside buildings

Source: ECOLOG Institute

Folie 14


Mobile phones

Frequency: - 880 – 915 MHz (GSM 900)

- 1710 – 1785 MHz (GSM 1800)

- 1920 – 1980 MHz (UMTS)

Transmit - up to 250 mW time averaged

Power: - up to 2 W peak

Number: - ~80 million

Coverage: - up to 20 km

Distance to

Persons: - body contact

Remarks: - power control

Source:

www.sonyericsson.com

Fo

lie 1

5

Exposu

re o

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ral p

ublic

, Novem

be

r 07

SA

R-M

easu

rem

en

ts

0

0,2

0,4

0,6

0,8 1

1,2

1,4

1,6

1,8 2

Nokia N93

Sony Ericsson W550i

Nokia E50

Nokia 6230i

Sony Ericsson W700i

Nokia 3250

Sony Ericsson K750i

Sony Ericsson W810i

Nokia 6233

Nokia 6270

Nokia 6131

Nokia N73

Sony Ericsson K510i

Sony Ericsson W800i

Nokia 6125

LG U8290

Samsung SGH-E770

Samsung SGH-X700

Siemens S75

Motorola ROKR

Sagem my 700X

BenQ-Siemens C81

BenQ-Siemens EF81

Motorola L7

Motorola V3x

Pantech GU-1100

Palm Treo 650

Mo

bile

ph

on

e

SAR value 10g [W/kg]•S

AR

is m

ea

su

red

und

er "w

ors

t case

" co

nd

ition

s

(ma

xim

al tra

nsm

it po

wer)

•ty

p. 1

0 –

75

% lim

it co

nsum

ptio

n

Folie 16



Determination of the specific absorption rate (SAR values) occurring during day-

to-day mobile phone use

(Telecom-Consult)

Determination of the real exposure from using mobile phones in partially shielded

rooms as compared to exposure under optimal conditions outdoors

(Telecom-Consult)

Source: Telecom-Consult

Folie 17


Exposure results: Averaged exposure

Position change

Inside a room, Nokia 6150 Inside a train, Nokia 6110/6150

• On average 10 – 50 % of "worst case" SAR, depending on

coverage and cell changes

• Further reduction due to DTX

Source: Telecom-Consult

Folie 18


TV Broadcast

Wendelstein

Frequency: - 47 – 68 MHz (analogue)

- 174 – 223 MHz (analogue, digital)

- 470 – 790 MHz (analogue, digital) - 790 – 862 MHz (digital)

Transmit - up to several 100 kW (ERP)

Power: per site

Transmitter: - typ. 5-15 main transmitters

each federal state (Germany)


Distance to


Folie 19



Determination of exposure to the population living near

digital radio and television

transmitters (IMST+EM Institute)

Folie 20


Exposure to Analogue TV and DVB-T (same region)

0,000001

0,00001

0,0001

0,001

0,01

0,1

1

10

100

0 50 100 150 200 250 300 350

measurement point

po

wer

den

sit

y [

% o

f li

mit

]

0,000001

0,00001

0,0001

0,001

0,01

0,1

1

10

100

0 50 100 150 200 250 300 350

measurement point

po

wer

den

sit

y [

% o

f li

mit

]

Analogue TV DVB-T

• More than 300 measurement points in Nuremberg and Munich region

• Points statistically distributed; proportional to population density

• Measurements before (A-TV) and after (DVB-T) switching to DVB-T

� Exposures mostly below 0.01 – 0.1 % of limit

Folie 21


FM radio and DAB

Frequency: - 88 – 108 MHz (FM radio)

- 174 – 223 MHz (DAB)

- 1452 – 1492 MHz (DAB)

Transmit - FM: typ. several 10 kW (ERP)

Power: DAB: typ. several kW per site

Transmitter: - several 100 (Germany)


Distance to


www.zinsik.de

Folie 22



Determination of exposure to the population living near

digital radio and television

transmitters (IMST+EM Institute)

Düsseldorf

Hamburg

Berlin

Stuttgart

München

Folie 23


Exposure to FM radio and DAB (same region)

FM radio DAB

• 300 measurement points in Nuremberg and Munich region

• Points statistically distributed; proportional to population density

� Exposures mostly below 0.01 – 0.1 % of limit

� DAB exhibits ~11 dB lower exposure compared to FM radio (median)

0,000001

0,00001

0,0001

0,001

0,01

0,1

1

10

100

0 50 100 150 200 250 300

measurement point

po

wer

den

sit

y [

% o

f li

mit

]

0,000001

0,00001

0,0001

0,001

0,01

0,1

1

10

100

0 50 100 150 200 250 300

measurement point

po

wer

den

sit

y [

% o

f li

mit

]

Folie 24


Long/Medium/Shortwave radio services

Frequency: - 148 – 255 kHz (LW)

- 0.526 – 1.6 MHz (MW)

- 3.4 – 26 MHz (SW)

Transmit - several 100 kW per site

Power: (up to 2 MW)

Transmitter: - several 10 (Germany)

Coverage: - several 100 km

Distance to


Folie 25


Exposure resultsStudy by Wuschek et al., 2003"Large area measurement of radio waves in Baden-Wurttemberg"

• 895 points, regular 2 x 2 km grid, outdoor

� Exposure may reach or exceed GSM/UMTS exposure near to base stations!

0,0001

0,001

0,01

0,1

1

10

100

1001 1052 1106 1156 2041 2092 2142 2193 2243 2293 2343 2393 2443 2493 2543 3014 3064 4037

measurement point

(ele

ctr

ic f

ield

str

en

gth

)² [

% o

f li

mit

])²

.

Folie 26


Wireless LAN (IEEE 802.11b)

Frequency: - 2400 – 2483.5 MHz

Transmitpower: - max. 100 mW EIRP

Transmitter: - several 100,000

Coverage: - several 10 meter

Distance to - access points: far field

Persons: - mobile: close to body

or body contact

Remarks: - power control by duty cycle

Folie 27



Determination of human exposure caused by indoor

wireless communication

technologies applied in homes and offices

(ARC Seibersdorf Research)

Determination the real field distribution of high frequency

electromagnetic fields near

wireless LAN installations (WLAN) in inner cities

(ARC Seibersdorf Research)

Source: ARC Seibersdorf Research

Folie 28


Exposure results (time and space averaged)

distance [m]

po

we

r d

en

sity [

mW

/m²]

po

we

r de

nsity

[% o

f limit]

0.1

0.01

0.001

0.0001

0.00001

• outdoor scenarios: typ. 10-11 – 0.001 %

• indoor scenarios: up to 0.1 %

• close to body operation: typ. 2 - 3 % of SAR-limit


Folie 29


Digital cordless phones: DECT

Frequency: - 1880 - 1900 MHz

Transmitpower: - max. 250 mW peak power

Transmitter: - several 100,000

Coverage: - several 10 meter

Distance to - base station: far field

Persons: - mobile: body contact

Remarks: - power control by duty cycle

Folie 30



Determination of human exposure caused by indoor wireless

communication technologies applied

in homes and offices(ARC Seibersdorf Research)

Results: time and space averaged in % of limit

• 2 DECT devices, 1 and 3 m:BS: 0.004 – 0.03 %,MS: 0.0002 – 0.004 %

• SAR10g: 0.6 – 8 %

• generic scenarios: 0.00007 – 0.0003 %

• mixed scenarios: 0.00007 – 0.023 %


Fo

lie 3

1

Exposu

re o

f gene

ral p

ublic

, Novem

be

r 07

Pu

tting

all re

su

lts to

geth

er ...

0,0

00001

0,0

0001

0,0

001

0,0

01

0,0

1

0,1 1

10

100

base stations worst

case

base stations

averaged

mobile phones

(SAR) worst case

mobile phones daily

life

analogue TV

DVB-T

FM radio

DAB

LMS radio

WLAN

DECT

rad

io s

erv

ice

limit consumption [% of power limit]

clo

se

to b

od

y

bo

dy c

onta

ct

Folie 32


... the same with median

0,000001

0,00001

0,0001

0,001

0,01

0,1

1

10

100

bas

e s

tati

on

s w

ors

t

ca

se

bas

e s

tati

on

s

av

era

ge

d

mo

bil

e p

ho

nes

(SA

R)

wo

rst

cas

e

mo

bil

e p

ho

ne

s d

ail

y

life

an

alo

gu

e T

V

DV

B-T

FM

ra

dio

DA

B

LM

S r

ad

io

WL

AN

DE

CT

radio service

lim

it c

on

su

mp

tio

n [

% o

f p

ow

er

lim

it]

indoor

outdoor

close to body

body contact

median

Be carefully with your interpretation!!!

Folie 33


Personal exposure meters (Dosimeters)

Antennessa EME Spy 120Maschek ESM-140

www.maschek.de

Fo

lie 3

4

Exposu

re o

f gene

ral p

ublic

, Novem

be

r 07

Fre

qu

en

cy b

an

ds A

nte

nn

essa

FM

GSM Tx

GSM Rx

GSM Rx

GSM Rx

DCS Tx

DCS Rx

DCS Rx

DCS RX

DECT

UMTS Tx

UMTS Rx

UMTS Rx

UMTS Rx

WIFI

TV3

Tetra

TV4&5

Pro

ble

ms w

ith c

ross-ta

lk

Folie 35


Measurement with "extra" exposure

Microwave oven,

30 cm

GSM/UMTS base

station, 350 m

Mobile phone,

70 cm

Folie 36


"Normal" situation

Folie 37


Dosimeters: Questions to be discussed

• Limited sensitivity

• Cross talk between different frequency bands

• Measurement accuracy

- Isotropicity

- Influence of the user

- Response to modulated signals

- Summation of multiple signals in the same band

• Functional and ergonomic aspects

�Dosimeters seem to be very helpful for epi-studies,(although their quality need to be investigated in detail)

Folie 38


Summary and conclusion

• Relevant exposures are:

- mobile phone base stations (GSM+UMTS) and mobile phones

- digital and analogue radio and TV broadcast

- Wireless LAN and DECT cordless phones

• Most services exhibit strong time variations (power control) andspace variations (fast fading) → worst case exposure differs from averaged exposure

• General comparison of exposures show:

- Strongest exposure by sources near to body/body contact

- Long/Medium/Shortwave radio service often underestimated

• Dosimeters seem to be very helpful for epi-studies,(although their quality need to be investigated in detail)

exposure of the general public to rf electromagnetic fields · transmitters radio broadcast...

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