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
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
Exposure of general public, November 07
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
Exposure of general public, November 07
Classification of relevant RF sources
Outdoor Household
Installation place
Mobile phone
base stationsMobile phones
DECT phones
WLAN applications
TV broadcast
transmitters
Radio broadcast
transmitters
Folie 5
Exposure of general public, November 07
Classification of relevant RF sources
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
Exposure of general public, November 07
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
Exposure of general public, November 07
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
Exposure of general public, November 07
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
Exposure of general public, November 07
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
Exposure of general public, November 07
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
Exposure of general public, November 07
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
Exposure of general public, November 07
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
Exposure of general public, November 07
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
f gene
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
Exposure of general public, November 07
Projects supported within DMF
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 of general public, November 07
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
Exposure of general public, November 07
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)
Coverage: - up to 60 km
Distance to
Persons: - far field
Folie 19
Exposure of general public, November 07
Projects supported within DMF
Determination of exposure to the population living near
digital radio and television
transmitters (IMST+EM Institute)
Folie 20
Exposure of general public, November 07
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
Exposure of general public, November 07
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)
Coverage: - up to 60 km
Distance to
Persons: - far field
www.zinsik.de
Folie 22
Exposure of general public, November 07
Projects supported within DMF
Determination of exposure to the population living near
digital radio and television
transmitters (IMST+EM Institute)
Düsseldorf
Hamburg
Berlin
Stuttgart
München
Folie 23
Exposure of general public, November 07
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
Exposure of general public, November 07
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
Persons: - far field
Folie 25
Exposure of general public, November 07
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
Exposure of general public, November 07
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
Exposure of general public, November 07
Projects supported within DMF
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 of general public, November 07
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
Source: ARC Seibersdorf Research
Folie 29
Exposure of general public, November 07
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
Exposure of general public, November 07
Projects supported within DMF
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 %
Source: ARC Seibersdorf Research
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
Exposure of general public, November 07
... 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
Exposure of general public, November 07
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
Exposure of general public, November 07
Measurement with "extra" exposure
Microwave oven,
30 cm
GSM/UMTS base
station, 350 m
Mobile phone,
70 cm
Folie 36
Exposure of general public, November 07
"Normal" situation
Folie 37
Exposure of general public, November 07
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
Exposure of general public, November 07
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)