re: Verdens Sundhedsorganisation rapport vedr. bio-EMF exposure
International Agency for Research on Cancer (IARC)
är världshälsoorganisationen WHO's grupp för cancerforskning.
WHO-IARC report on bio-EMF exposure, preliminary release
webposted 06.09.20001
Scott_Hill@...
(I have included some info in Swedish for our Scandinavian members)

IARC Monographs on the Evaluation of Carcinogenic Risks to Humans

Static and Extremely Low Frequency Electric and Magnetic Fields
(Vol. 80) (19–26 June 2001)
(in preparation)

A working group of 21 scientific experts from 10 countries met in Lyon
to evaluate possible carcinogenic hazards to human beings from
exposures to static and
extremely low frequency (ELF) electric and magnetic fields. This
volume is the first in a planned series of two IARC Monographs volumes
on various kinds of
non-ionizing radiation in the frequency range below that of visible
light.

ELF magnetic field exposures result from proximity to electric power
transmission lines, household wiring, and electric appliances and are
in addition to the exposure
that results from the earth's magnetic field. Magnetic fields are
measured in units of microTesla; the earth's static magnetic field
varies from 25 microTesla at the
equator to 65 microTesla at the poles.

Since the first report suggesting an association between residential
electric and magnetic fields and childhood cancer, notably leukaemia,
was published in 1979,
dozens of studies have examined this association. Overall, for the
vast majority of children who are exposed to residential ELF magnetic
fields less than 0.4
microTesla, there is little evidence of any increased risk for
leukaemia. There is inadequate evidence that electric fields are
associated with childhood leukaemia, and
there is no consistent relationship between childhood brain tumours or
other childhood solid tumours and residential ELF electric and
magnetic fields. However,
pooled analyses of data from a number of well-conducted studies show a
fairly consistent statistical association between childhood leukaemia
and power-frequency
residential magnetic field strengths above 0.4 microTesla, with an
approximately two-fold increase in risk. This is unlikely to be due to
chance, but may be affected
by selection bias. Therefore this association between childhood
leukemia and high residential magnetic field strengths was judged
limited evidence for excess cancer
risk in exposed humans.

There is no consistent evidence that residential or occupational
exposures of adults are related to excess risks of cancer at any site,
although in one Swedish study
combined residential and occupational exposures were associated with a
significantly increased risk for all leukaemia subtypes except chronic
lymphocytic
leukaemia. Evidence for excess cancer risks of all other kinds, in
children and in adults, as a result of exposure to ELF electric and
magnetic fields was considered
inadequate.

Numerous studies to investigate carcinogenicity of magnetic fields
have been conducted in experimental animals. These have included
long-term bioassays of
exposures to magnetic fields alone, and exposures of rats and mice to
magnetic fields in combination with known carcinogens. Bioassays of
magnetic fields alone
generally were negative, although one study that was conducted in both
mice and rats of both sexes showed non-exposure related increases in
thyroid C-cell
tumours in male rats only. Multistage carcinogenesis studies showed no
consistent enhancement of chemically initiated mammary tumours in rats
or of skin tumours in
mice. Magnetic fields had no effects on the incidence of chemically
initiated liver tumours in rats or of leukaemia/lymphoma in mice or
rats. Overall, evidence for
carcinogenicity of ELF magnetic fields in experimental animals was
judged inadequate. No data on carcinogenicity to animals of static
magnetic fields, or of static or
ELF electric fields, were available to the working group.

Although many hypotheses have been put forward to explain possible
carcinogenic effects of ELF electric or magnetic fields, no scientific
explanation for
carcinogenicity of these fields has been established.

Overall, extremely low frequency magnetic fields were evaluated as
possibly carcinogenic to humans (Group 2B), based on the statistical
association of higher
level residential ELF magnetic fields and increased risk for childhood
leukaemia. Static magnetic fields and static and extremely low
frequency electric fields could
not be classified as to carcinogenicity to humans (Group 3).

Last updated: 3 July 2001


An expert scientific working group of the Monographs Programme of the
International Agency for Research on Cancer (IARC) has concluded
its review of health effects of static and extremely low frequency
(ELF) electric and magnetic fields. Such fields include the earth's
magnetic
field, and also originate from electrical power transmission lines,
electrical wiring in buildings, and electric appliances. Magnetic
fields are
measured in units of microTesla; the earth's static magnetic field,
to which everyone is exposed, varies from 25 microTesla at the equator
to
65 microTesla at the poles. Most research on health effects has been
done on ELF magnetic fields with frequencies of 50 or 60 Hz.

Reports were first published in 1979 that childhood cancer might be
associated with exposures to residential ELF fields. Numerous studies
in many countries have been undertaken since then of possible
increased cancer risks in children and adults from ELF magnetic field
exposures. Special attention has focussed on leukaemia and on brain
tumours, which early reports had suggested might be increased. IARC
has now concluded that ELF magnetic fields are possibly carcinogenic
to humans, based on consistent statistical associations of high level
residential magnetic fields with a doubling of risk of childhood
leukaemia. Children who are exposed to residential ELF magnetic fields
less
than 0.4 microTesla have no increased risk for leukaemia. Because of
insufficient data, static magnetic fields and static and extremely low
frequency electric fields could not be classified as to carcinogenic
risk to humans.

However, pooled analyses of data from a number of well-conducted
studies show a fairly consistent statistical association between a
doubling of risk of childhood leukaemia and power-frequency (50 or 60
Hz) residential ELF magnetic field strengths above 0.4 microTesla. In
contrast, no consistent evidence was found that childhood exposures
to ELF electric or magnetic fields are associated with brain tumours
or
any other kinds of solid tumours. No consistent evidence was found
that residential or occupational exposures of adults to ELF magnetic
fields increase risk for any kind of cancer.

Studies in experimental animals have not shown a consistent
carcinogenic or co-carcinogenic effects of exposures to ELF magnetic
fields,
and no scientific explanation has been established for the observed
association of increased childhood leukaemia risk with increasing
residential ELF magnetic field exposure.

Health effects of radiofrequency electromagnetic fields, which are
produced by such sources as radio and television transmission towers,
portable telephones, and radar, were not evaluated by the IARC
working group. These exposures will be reviewed by the IARC Monographs
Programme when research that is currently in progress has been
published, most likely in 2005.

For further details of the Monographs evaluation, consult
http://monographs.iarc.fr, under "Agents most recently evaluated," or
inquire by e-mail to cie@....

For further details of current research at IARC on electric and
magnetic fields, inquire by e-mail to cardis@....

For more general information, contact Dr Nicolas Gaudin, Chief,
Communications (gaudin@...).
agnetiska fält klassificerade som möjligen cancerframkallande

21 världsledande experter inom forskning om elektriska och magnetiska
fält enades i dagarna om att
klassificera lågfrekventa magnetiska fält som möjligen
cancerframkallande. -För första gången har
forskare från hela världen nått konsensus i frågan, säger professor
Kjell Hansson Mild,
Arbetslivsinstitutet.

Hansson Mild var ende svenska deltagare i IARC:s expertgrupp
(International Agency for Research on
Cancer) som nyligen samlades åtta dagar i Frankrike för att gå igenom
litteratur om elektriska och magnetiska
fält. IARC klassificerar cancerrisker i fyra nivåer. I grupp 1 finns
ämnen som vetenskapen med säkerhet vet är
cancerframkallande, till exempel asbest, radon och tobak. I grupp 2A
finns ämnen som troligtvis är
cancerframkallande, till exempel formaldehyd, solarier och akrylamid
(som används vid bygget av
Hallandsåsen). I grupp 2B finns möjligen cancerframkallande ämnen som
giftet ddt, bly och nu också
elektromagnetiska fält.

-Tidigare gjorde en expertgrupp i USA bedömningen att
elektromagnetiska fält ska klassas i grupp 2B. I
Frankrike enades vi om att bedömningen gäller över hela världen.
Total enighet rådde, säger Kjell Hansson
Mild.

Grupp 3 bland nivåerna som klassificerar cancerrisker är inte
tillräckligt underlag för bedömning, och det rör
sig om exempelvis lysrörsbelysning, koffein och kvicksilver. Grupp 4
tar upp olika ämnen som troligtvis inte är
cancerframkallande.

För några år sedan beslutade Arbetsmiljöverket, Socialstyrelsen,
Statens strålskyddsinstitut, Elsäkerhetsverket
och Boverket att en försiktighetsprincip ska gälla vid nybyggnation,
nykonstruktion och ombyggnad. Principen
går ut på att man måste ta hänsyn till magnetfältsexponering. Den
aktuella klassificeringen understryker att
det var ett korrekt fattat beslut:

-Med det beslutet är vi unika i Sverige. Inget annat land har visat
samma förutseende som vi. Andra länder
bör nu ta efter vårt exempel, säger Kjell Hansson Mild.

Han understryker att det i fortsättningen är viktigt att forskningen
kring detta fortsätter. Fortfarande vet
vetenskapen inte vad det är som är farligt: långvarig exponering för
svaga lågfrekventa magnetfält eller stark
exponering under kortare perioder.


Frågor: Kjell Hansson Mild 090-17 60 17, kjell.hansson.mild@...