Subject: Lancet - Commentary, Repacholi and Ahlbom (fwd)
Date: Fri, 3 Dec 1999 092852 -0600 (CST)
From: "Roy L. Beavers"
To: emfguru
--------------------------------------------------
.......I strongly recommend that everybody (particularly all of "the
press") MEMORIZE the following.....
[Note. Dr. Repacholi is well known to this group as the leader of the
WHO research program on EMF. Dr. Ahlbom is perhaps less well known,
but he is an equally authoritative expert from Sweden. He has a totally
unblemished reputation for total objectivity.....!!)
Roy Beavers (EMFguru)
roy@emfguru.com
.....It is better to light a single candle than to curse the darkness.....
NEW!!! Website
...................People are more important than profits.................
DO YOU KNOW OF OTHERS WHO SHOULD BE ON THIS LIST??
---------- Forwarded message ----------
Date: Fri, 03 Dec 1999 14:34:09
From: Alasdair Philips
To: "Roy L. Beavers"
Cc: Louis Slesin / Microwave News ,
Nicholas Clough
Subject: Lancet - Commentary, Repacholi and Ahlbom
Lancet CommentaryVolume 354, Number 9194 4 December 1999
Link between electromagnetic fields and childhood cancer unresolved
The long-awaited UK Childhood Cancer Study (UKCCS) on exposure to
power-frequency magnetic fields and risk of childhood cancer published
in today's Lancet does not support the hypothesis that exposure to
magnetic fields, associated with the use or transmission of electricity
in the UK, increases the risk of childhood leukaemia, central nervous
system tumours, or any other childhood cancer.
Reviews of epidemiological studies conducted by the US National Research
Council,1 WHO,2 and the National Institute of Environmental Health
Sciences (NIEHS)3 have suggested that there is a weak link between
exposure to power-frequency magnetic fields and childhood leukaemia,
with an odds ratio of about 1·5. Using the International Agency for
Research on Cancer criteria for classifying potential carcinogens, an
international working group convened by the NIEHS3 rated exposure to
power-frequency fields as a category 2B, a possible human carcinogen.
WHO, through its International EMF Project, has been promoting research
that attempts to address this 2B classification. From WHO's viewpoint,
although the UKCCS is very large and well conducted, it is not the
"definitive" study many scientists have been hoping for.
The first reason is that this study was designed many years ago, so the
exposure assessment relies on time-weighted average (TWA) fields. TWA
has been used in many studies but does not relate to any known mechanism
of action of low-frequency fields in tissues. A recent WHO report4
recommends that, although TWA should continue to be used in future
epidemiological studies for comparison purposes, other measures that
relate to known mechanisms should also be included in the
exposure-assessment protocol. Key among these measures is an assessment
of any rapid changes in the magnetic field (transients) that occur when
appliances are used, and in transients from distribution lines. Currents
induced by power transients can produce signals in cells above the
cell's normal electrical-noise levels.5
The second reason why the study is not definitive is the low numbers of
children in the higher exposure categories. As the UKCCS investigators
state, only 2·3% of their controls had been exposed to magnetic fields
over 0·2 µT. Although this percentage is similar to that in Germany
(2%),6 in the US study7 it was 11·4% and in the Canadian study8 15·4%.
This difference reflects, in part, the line voltage in North America of
about 110 V, and in Europe of 220 V. Thus for the same power consumption
North Americans use twice as much current as Europeans do, and so are
exposed to about double the magnetic-field strength. Another factor
influencing the level of magnetic-field exposure between the two
continents relates to how the power is distributed--for example, how
electrical wiring is configured in homes and how the currents are
earthed. Whatever the explanation, the small numbers in the higher
exposure categories mean that the UKCCS provide evidence only for
exposures of up to 0·2 µT.
The third reason is that the small numbers of cases and controls in the
higher exposure categories are unlikely to significantly affect the
results of previous meta-analyses and reviews suggesting a weak link
between power-frequency magnetic-field exposure and childhood leukaemia.
1-3 An analysis, funded by the European Union, which includes the UKCCS,
is near completion.
Today's Lancet also carries a research letter reporting some new data
from a previously published New Zealand study .9 However, the study has
the same inadequacies as the UKCCS.
A major childhood leukaemia study is being done by Japan's National
Institute of Environmental Studies. This study will take account of
transients in the assessment of exposure to magnetic fields. 1500 cases
(1000 leukaemia and 500 brain tumours) and a similar number of matching
controls will be recruited. Because Japan is highly industrialised, the
study is expected to have large numbers in the high-exposure groups.
This study, in conjunction with those being done in Germany and Italy,
may be one of the last hopes of finally resolving the vexing issue of
whether there is truly an increased risk of childhood cancer from
exposure to magnetic fields or whether the weak association is occurring
by chance.
*Michael H Repacholi, Anders Ahlbom
------------------------------------------------------------------------
*Division of Occupational and Environmental Health, World Health
Organization, CH-1211, Geneva 27, Switzerland; and National Institute of
Environmental Medicine, Karolinska Institutet, Sweden
1 National Research Council. Possible health effects of exposure to
residential electric and magnetic fields. National Research Council,
Washington: National Academy Press, 1996.
2 Repacholi MH, Greenebaum B. Interaction of static and extremely low
frequency electric and magnetic fields with living systems: health
effects and research needs. Bioelectromagnetics 1999; 20: 133-60.
3 Portier CJ, Wolfe MS (eds). National Institute of Environmental Health
Sciences Working Group Report. Assessment of health effects from
exposure to power-line frequency electric and magnetic fields (NIH
publication no. 98-3981). Research Triangle Park: NIEHS, 1998.
4 McKinlay AF, Repacholi MH, eds. Exposure metrics and dosimetry for EMF
epidemiology: Proceedings of an International Workshop held at the
National Radiological Protection Board, Chilton, UK, Sept 7-9, 1998.
Radiation Protection Dosimetry 1999; 83 (1-2): 1-194.
5 Electric Power Research Institute. Residential transient magnetic
field research: interim report, project RP2966-07 (report TR-103470).
Palo Alto, California: EPRI, 1994.
6 Michaelis J, Shuz J, Meinert R, et al. Combined risk estimates for two
German population-based case-control studies on residential magnetic
fields and childhood acute leukemia Epidemiology 1998; 9: 92-94.
7 Linet MS, Hatch EE, Kleinerman RA, et al. Residential exposure to
magnetic fields and acute lymphoblastic leukemia in children. N Engl J
Med 1997; 337: 1-7.
8 McBride ML, Gallagher RP, Thériault G, et al. Power-frequency electric
and magnetic fields and risk of childhood leukemia in Canada. Am J
Epidemiol 1999; 149: 831-42.
9 Dockerty JD, Elwood JM, Skegg DCG, Herbison GP. Electromagn
Electromagnetic field exposures and childhood cancers in NeCancer Causes
Control 1998; 9: 299-300 (erratum in 1999; 10: 641)
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Alasdair Philips, BSc(Eng), DAgE, MIAgE
Director, UK Powerwatch, (aphilips@gn.apc.org)
EMC Engineer and EMF-bioeffects researcher
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Archive provided courtesy of WaveGuide, http://www.wave-guide.org
Reprinted with permission of Roy Beavers, http://www.emfguru.com