Monday 16 May 2011

RF PRT1

11.11.2009
1
GEISLAVARNIR RÍKISINS
ICELANDIC RADIATION SAFETY AUTHORITY
Danish National Board of Health (Sundhedsstyrelsen)
Finnish Radiation and Nuclear Safety Authority (Säteilyturvakeskus, STUK)
Icelandic Radiation Safety Authority (Geislavarnir Rikisins)
Norwegian Radiation Protection Authority (Statens strålevern)
Swedish Radiation Safety Authority (Strålsäkerhetsmyndigheten)
EXPOSURE OF THE GENERAL PUBLIC TO
RADIOFREQUENCY ELECTROMAGNETIC FIELDS
- A joint statement from the Nordic Radiation Safety Authorities -
This statement addresses the exposure of the general public to radiofrequency (RF) radiation emitted
continuously by fixed transmitters located in our surroundings. The joint statement regarding mobile
phones issued in 2004 is still valid (Mobile Telephony and Health – A common approach for the
Nordic competent authorities).
Introduction
The introduction of new sources of electromagnetic fields is fast in the Nordic countries due to
technological developments. Radio and TV transmitters have existed throughout the Nordic countries
for more than 70 and 50 years, respectively. The first generation (NMT) of mobile telecommunication
networks were introduced 30 years ago, the second generation (GSM) came 25 years ago and
third generation (UMTS) networks started around 2000 while the public safety radio network has
been (or soon will be) started up in the Nordic countries. In addition, cordless telephones have been
in use for more than 25 years and wireless networks are used in the home, offices and in public areas.
Wireless alarm and baby monitoring systems using radiofrequency signals are also common, as well
as wireless personal identification systems. Bluetooth technology has been adopted for use in many
pc applications such as the wireless mouse and keyboard, as well as in hands-free devices for mobile
phones.
The above are all examples of sources emitting electromagnetic fields in the radiofrequency range
from 10 MHz to 2.5 GHz. The exposure of the general public in the Nordic countries due to these
sources is well below the international recommendations given by International Commission on Non-
Ionizing Radiation Protection (ICNIRP).

RF PRT 2

11.11.2009
3
Electromagnetic hypersensitivity (EHS)
Issues regarding reported cases of electromagnetic hypersensitivity (EHS) are complex and not easily
addressed. According to the World Health Organisation (WHO) there is no scientific basis to link
EHS symptoms to exposure to an electromagnetic field [WHO, 2005]. Therefore, the Nordic
radiation safety authorities regard EHS as a medical issue, which needs to be dealt with by health
authorities, rather than as a radiation safety issue. The symptoms related to EHS can be real and
severe for sufferers, however, and hence it is important to continue studies aimed at achieving a better
understanding of the causes of EHS.
Conclusion
The Nordic authorities agree that there is no scientific evidence for adverse health effects caused by
radiofrequency field strengths in the normal living environment at present. This conclusion concurs
with the opinion of international scientific and advisory bodies listed as references below [ICNIRP,
1998 and 2009; WHO, 2005 and 2006; SCENIHR 2009; SSI`s Independent Expert Group on Electromagnetic
Fields, 2007]. The Nordic authorities therefore at present see no need for a common recommendation
for further actions to reduce these radiofrequency fields.
It is important to note, however, that many of the technologies which use radiofrequency electromagnetic
fields have only been prevalent for less than two decades. It is therefore important to continue
active research on the possible health effects of radiofrequency radiation and reappraisal of the
scientific literature concerning this issue. It is also important to follow developments in exposure
from different sources and the possible health consequences from such development.
The Nordic authorities wish to emphasize the fact that to reduce the total exposure received by the
general public from wireless communication systems, it is necessary to carry out integrated planning
that takes into account radiation emitted both from fixed antennas and hand-held devices such as
mobile phones. Furthermore, in terms of overall public exposure, mobile phones are a much more
significant source of radiofrequency radiation than fixed antennas. If the number of fixed antennas is
reduced, mobile phones will need to use higher power to maintain their connection, thereby the exposure
of the general public may increase.
For further information about this and possible actions to reduce exposure from mobile phones and
other devices, see the web-pages of the national authorities listed below.
References
Mobile Telephony and Health – A common approach for the Nordic competent authorities (Available
at
ICNIRP. 1998. Guidelines for limiting exposure to time-varying electric, magnetic, and electromagnetic
fields (up to 300 GHz). Health Phys 74:494–522. (Available at
http://www.icnirp.de/documents/emfgdl.pdf)
ICNIRP. 2009. ICNIRP Statement on the “Guidelines for Limiting Exposure to Time-Varying Electric,
Magnetic, and Electromagnetic Fields (up to 300 GHz)”. Health Phys 97:257–258. (Available at
http://www.icnirp.de/documents/StatementEMF.pdf)
World Health Organization (WHO). 2005. Fact sheet 296: Electromagnetic fields and public health -
Electromagnetic Hypersensitivity. (Available at
http://www.who.int/mediacentre/factsheets/fs296/en/index.html)
http://www.nrpa.no/archive/Internett/div_dokument/IIS/NordicMobile.pdf)

PART3 RF WAVES

11.11.2009
3
Electromagnetic hypersensitivity (EHS)
Issues regarding reported cases of electromagnetic hypersensitivity (EHS) are complex and not easily
addressed. According to the World Health Organisation (WHO) there is no scientific basis to link
EHS symptoms to exposure to an electromagnetic field [WHO, 2005]. Therefore, the Nordic
radiation safety authorities regard EHS as a medical issue, which needs to be dealt with by health
authorities, rather than as a radiation safety issue. The symptoms related to EHS can be real and
severe for sufferers, however, and hence it is important to continue studies aimed at achieving a better
understanding of the causes of EHS.
Conclusion
The Nordic authorities agree that there is no scientific evidence for adverse health effects caused by
radiofrequency field strengths in the normal living environment at present. This conclusion concurs
with the opinion of international scientific and advisory bodies listed as references below [ICNIRP,
1998 and 2009; WHO, 2005 and 2006; SCENIHR 2009; SSI`s Independent Expert Group on Electromagnetic
Fields, 2007]. The Nordic authorities therefore at present see no need for a common recommendation
for further actions to reduce these radiofrequency fields.
It is important to note, however, that many of the technologies which use radiofrequency electromagnetic
fields have only been prevalent for less than two decades. It is therefore important to continue
active research on the possible health effects of radiofrequency radiation and reappraisal of the
scientific literature concerning this issue. It is also important to follow developments in exposure
from different sources and the possible health consequences from such development.
The Nordic authorities wish to emphasize the fact that to reduce the total exposure received by the
general public from wireless communication systems, it is necessary to carry out integrated planning
that takes into account radiation emitted both from fixed antennas and hand-held devices such as
mobile phones. Furthermore, in terms of overall public exposure, mobile phones are a much more
significant source of radiofrequency radiation than fixed antennas. If the number of fixed antennas is
reduced, mobile phones will need to use higher power to maintain their connection, thereby the exposure
of the general public may increase.
For further information about this and possible actions to reduce exposure from mobile phones and
other devices, see the web-pages of the national authorities listed below.
References
Mobile Telephony and Health – A common approach for the Nordic competent authorities (Available
at
ICNIRP. 1998. Guidelines for limiting exposure to time-varying electric, magnetic, and electromagnetic
fields (up to 300 GHz). Health Phys 74:494–522. (Available at
http://www.icnirp.de/documents/emfgdl.pdf)
ICNIRP. 2009. ICNIRP Statement on the “Guidelines for Limiting Exposure to Time-Varying Electric,
Magnetic, and Electromagnetic Fields (up to 300 GHz)”. Health Phys 97:257–258. (Available at
http://www.icnirp.de/documents/StatementEMF.pdf)
World Health Organization (WHO). 2005. Fact sheet 296: Electromagnetic fields and public health -
Electromagnetic Hypersensitivity. (Available at
http://www.who.int/mediacentre/factsheets/fs296/en/index.html)
http://www.nrpa.no/archive/Internett/div_dokument/IIS/NordicMobile.pdf)

PART4 RF WAVES

World Health Organization (WHO). 2006. Fact sheet No 304: Electromagnetic fields and public
health. (Available at http://www.who.int/mediacentre/factsheets/fs304/en/index.html)
SCENHIR (The European Commission Scientific Committee on Emerging and Newly Identified
Health Risks) 2009. Health effects of exposure to EMF, European commission 2009. (Available at
http://ec.europa.eu/health/ph_risk/committees/04_scenihr/docs/scenihr_o_022.pdf)
SSI`s independent expert group on Electromagnetic fields. 2007. (Statens strålskyddsinstitut) SSI
Rapport 2008:12. Recent Research on EMF and Health Risks. Fifth Annual Report from SSI`s independent
expert group on Electromagnetic fields. (Available at
http://www.stralsakerhetsmyndigheten.se/Publikationer/Rapport/Stralskydd/2008/200812/)
Further reading:
www.ssm.se
www.stralevernet.no
www.sis.dk
www.gr.is
www.stuk.fi

PART 5 RF WAVES

11.11.2009
ANNEX -
ANNEX:
1
Exposure of the general public to radiofrequency fields
1. Introduction
This document presents typical exposure of the general public to radiofrequency (RF) radiation in
every-day situations. The lists of RF source technologies/devices (see Table 1 & 2) and exposure
scenarios are not complete since there are many applications that can emit radiofrequencies and new
sources appear regularly. It is however unlikely, due to general rules governing the design of radio
systems, that any new technology will cause significantly higher exposures to the general public in
the foreseeable future than the examples introduced here.
Table 1. An overview of the properties of commonly used RF emitting devices that are used close to
the individual. The general public’s exposure limit for local specific absorption rate (SAR
head and trunk regions is 2 W/kg. The limit for occupational exposure (e.g. police radio) is 10 W/kg.
The given values are for maximum exposure i.e. direct contact between RF transmitter and affected
tissue.
*) for the
Technology Related acronyms Frequency
(MHz)
Maximum
(time averaged)
output power (mW)
Maximum
SAR
(W/kg)
GSM 900 900 250 1.4
GSM 1800 (formerly
DCS 1800)
1800 125 1
Mobile phones
UMTS (also 3G) 1950 125
1
WLAN (also WiFi) 2450 100 1
3G 1950
WiMAX 3500 160 1
Wireless internet
terminals of the
computers
(For base stations,
see Table 2)
Flash-OFDM (@450
in Finland)
450 200
0.5
Cordless phones DECT 1900 10
<0.1
Cordless mouses
and keyboards
Bluetooth 2450 1 or 2.5
<0.01
Cordless hands free
sets
Bluetooth 2450 1 or 2.5
<0.01
PMR446 446 500 0.4
DECT 1900 10 0.03
Baby monitors
+ others 27 (typical) 10
<0.01
Professional mobile
radio (police etc.)
TETRA 400 250
(750 also)
1
(3)
125 1
*
radiofrequency electromagnetic field. It is defined as the power absorbed per mass of tissue and has units of watts per
kilogram. SAR is usually averaged either over the whole body, or over a smaller sample volume. Recommended
exposure limits are set by the International Commission Non-Ionizing Radiation Protection (ICNIRP).
Specific absorption rate (SAR) is a measure of the rate at which energy is absorbed by the body when exposed to aalso other mobile phone bands, if 3G not available

PART6 RF WAVES

11.11.2009
ANNEX -
2
2. Exposure sources
The exposure to an individual caused by any single RF source is strongly dependent on the distance
between the source and the individual, the source output power and duration of RF transmission.
Therefore, regarding exposure there are two main types of devices; small devices used close to the
individual (hand-held and/or body-worn) and fixed transmitters. Exposure caused by devices used
close to the individual is localised and usually occasional, since RF transmission shuts down while
not in use, though exposure to RF can be near the ICNIRP exposure limits when such devices are in
use. Fixed transmitters often use high output powers and typically transmit RF continuously. Recommended
exposure limits can therefore be exceeded in close proximity to such sources. Fixed
transmitters are, however, usually installed in places where the general public does not have access,
such that the typical exposure caused by fixed transmitters is very low. Table 1 and 2 list some properties
of the most common RF technologies in use.
Table 2. An overview of commonly used fixed radio transmitters including information regarding
frequency and output power
Technology Related acronyms Frequency
range
(MHz)
Typical output
power
Typical power density
mW/m
2
GSM 900 900 < 0.1
GSM 1800 (former
DCS 1800)
1800 < 0.1
Mobile phone
base stations
UMTS (also 3G) 2150
20 W
< 0.1
TV broadcasts
(digital)
DVB-T 500 - 900 15 kW
< 0.01
Voice radio
broadcasts
VHF, FM-radio 87-108 50 kW
< 0.001
WLAN (also WiFi) 2450 100 mW
3G
WiMAX 3500 1 W
Wireless internet
connections
(base stations)
Flash-OFDM
(@450 in Finland)
450 up to 20 W
Cordless phone
(fixed part)
DECT 1900 10 mW (single
phone
system)
Professional
mobile radio
(police etc.)
TETRA 400 up to 100 W
3G is based on regular mobile phone base stations (see above)
2.1 Handheld and body worn devices
The highest output powers of hand-held/ body worn devices (e.g., mobile phones, laptops incorporating
a WLAN card or other wireless network adapter) are typically in the 100–500 mW range. The
output power is therefore relatively low, though a large fraction can be absorbed by the user leading
to exposures of the same order of magnitude as recommended exposure limits for localised exposure
to the general public (
small due to the low output power of such devices. In addition, such devices are typically used only
SAR limit of 2 W/kg). However, average whole-body exposures will always be

PART7 RF WAVES

11.11.2009
ANNEX -
occasionally and transmit RF only when the device is communicating. Moreover, some devices such
as mobile phones automatically decrease output power if possible i.e., in
areas where reception is good. Hence, typical exposure from these devices is lower than the theoretical
maximum; 0.1-0.5 and <0.01 of maximum values for GSM and 3G, respectively. Exposure
caused by small-range devices (e.g., cordless DECT phones, Bluetooth devices etc.) is typically only
a few percent of exposure limits.
Exposure to RF caused by a small-size low power transmitter generally decreases rapidly with increasing
distance from the source. A 30 cm gap between the receiving body and the transmitter typically
decreases exposure by a factor 100 when compared to direct contact exposure. Therefore, exposure
concerns mainly the user of the device. The individual exposure from such sources is reduced by
increasing the distance between user and device. This can be easily done by e.g., using hands-free for
voice calls and/or placing baby monitors, WLAN terminals etc such that they are not touching the
individual.
3
2.2. Fixed transmitters
Numerous technologies utilise fixed RF transmitters. Signals from WLAN, WiMAX and mobile
phone networks are transmitted by base stations, while TV and voice radio broadcasts are sent via
fixed transmitter antennas in high masts. Transmission powers in these devices range from milliwatt
(mW) to kilowatts (kW).
The antennas transmitting at the highest power levels (kilowatt-range) are the mast-mounted TV and
VHF voice radio transmitters. Power densities measured at ground level are low, however, since the
antennas are mounted 100–300 m above ground. The main RF transmission beam is targeted towards
the horizon; hence virtually all the RF power surpass people living in the vicinity of the mast (see
Fig. 1). Measurements performed around typical broadcasting masts have shown that the field
strengths depend more on the terrain (by factor 1000) than on the distance from the source. The highest
measured values in a normal living environment have been approximately 0.1 mW/m
to measurements in the Nordic countries, though more typical values are between 0.0001 –
0.001 mW/m
due to a lower transmission power being necessary for a single TV program. However, the
number of TV channels will increase and presumably all former frequencies of analogous TV will be
utilised again for digital broadcasts at some time in the future leading to background RF fields being
in the same order of magnitude as before the digitalisation.
2, according2. The introduction of digital TV broadcasting appears to have decreased overall exposure,
Fig.1. Radiowaves from mast-mounted antennas surpasses the people living in the vicinity of the
mast.