Academy Times Lecture

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• Academy Times Lecture
• Overhead Powerlines a Health Hazard?
• By Dr Michael Crumpton CBE FRS
• Wednesday 12 May at 7.30 pm, Burke Theatre, TCD

JD Bernal
Is it possible that electromagnetic fields
associated with power distribution can have
adverse health effects?
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When one admits that nothing is certain, one
must also add that some things are more certain
than others. Bertrand Russell
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The EMF Biological Research Trust - is a
UK-based medical research charity which funds
basic research on the biological effects of
the environmental extremely-low-frequency
electro- magnetic fields (ELF EMF) commonly
associated with the distribution of electric
power. It is funded by donations from National
Grid Transco plc. The research programme is
administered by a Scientific Advisory Committee
which is totally independent of the electricity
transmission industry. The Trust encourages
publication of results of the work it funds and
the content of such publications is entirely the
responsibility of the grantholders.
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Environmental extremely-low-frequency (ELF)
magnetic fields Characteristics Oscillating at
50/60 hertz (Hz) Strength less than 100
microtesla (µT) Commonly referred to as ELF EMF
Do not include mobile-phone/base-station
emissions
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A pooled analysis of magnetic fields and
childhood leukaemia Ahlbom A, Day N, Feychting
M et al British Journal of Cancer (2000) 83
692-698 A pooled analysis of magnetic
fields, wire codes and childhood leukemia
Greenland S, Sheppard AR, Kaune WT et al,
Epidemiology (2000) 11 624-634
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Power-frequency fields in homes
UK
1 or 2
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USA
0
100
200
300
400
500
magnetic field / nT
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Epidemiology perspectives 1. 0.4-?T field is
very weak cf Earths static field of 50
?T 2. Some 300,000 persons in the UK are exposed
to 0.4-?T power-frequency fields 3.
Two-fold increase in risk corresponds to an extra
two cases per year out of 500 4. No
known direct physical mechanism by which
weak fields can induce a biological response 5.
No strong support from laboratory experiments
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Outcomes 1. No causal mechanism 2. Results
are indicative no absolute certainty 3.
IARC classifies ELF magnetic fields as possibly
carcinogenic 4. NRPB guidelines indicate
that exposures below 100 µT are safe for the
general public
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Trusts response To support the very best
scientists To provide funds to Explore a
possible direct biophysical mechanism. Perform
laboratory experiments on cellular
systems (a) Replication experiments
(b) Exploit new technologies in genomics and
proteomics to explore environmental
stress responses
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radical pair
singlet
dissociation
recombination
molecule
triplet
conversion to triplet promoted by applied
magnetic field
free radicals
separation

P. J. Hore C. R. Timmel Oxford
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Low Field Effect
NMe2
pyrene
dimethylaniline
P. J. Hore C. R. Timmel Oxford
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Radical-pair mechanism challenges 1. Do weak
fields affect the amount of free radicals? 2.
Need to progress from model systems to more
relevant biological systems 3. Need for an
amplification step?
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Trusts response To support the very best
scientists To provide funds to Explore a
possible direct biophysical mechanism. Perform
laboratory experiments on cellular
systems (a) Replication experiments
(b) Exploit new technologies in genomics and
proteomics to explore environmental
stress responses
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Specific region of the c-myc promoter is
responsive to electric and magnetic fields Lin
H, Goodman R and Shirley-Henderson A J. Cell.
Biochem. (1994) 54 281-288 No effect of 60-Hz
electromagnetic fields on myc or ?-actin
expression in human leukaemic cells Lacy-Hulbert
A, Wilkins RC, Hesketh TR and Metcalfe
JC Radiation Research (1995) 144 8-17
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Exposure of B-lineage lymphoid-cells to
low-energy electromagnetic fields stimulates Lyn
kinase Uckun FM, Kurosaki T, Jin J, Jun X,
Morgan A, Takata M, Bolen J and Luben R J.
Biol. Chem. (1995) 270, 27666-27670 Lyn and Syk
tyrosine kinases are not activated in B-lineage
lymphoid cells exposed to low-energy
electromagnetic fields Woods M, Bobanovic F,
Brown D and Alexander DR FASEB Journal (2000) 14,
2284-2290
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Replication experiments qualifications 1.
Qualified support from original investigators 2.
Absolute requirement not to replicate bad
science 3. Personal bias and codes of
conduct 4. Publication bias towards positive
results
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Trusts response To support the very best
scientists To provide funds to Explore a
possible direct biophysical mechanism. Perform
laboratory experiments on cellular
systems (a) Replication experiments
(b) Exploit new technologies in genomics and
proteomics to explore environmental
stress responses
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Progress in science depends on new techniques,
new discoveries and new ideas, probably in that
order. Sydney Brenner, Nature, 5 May 1980 and 7
June 1990
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Heavy metals
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S. pombe EMF experimental design
Sham
200uT to 1mT static fields and alternating
(e.g. 50 Hz) fields
RNA
S. pombe microarrays
Changes in gene expression pattern Compare to
known stress responses Regulatory pathways
involved
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Cd
H2O2
1-4
Cd
H2O2
1-1
1-2
1-3
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Gene expression results assessment
1. Assay sensitivity a smaller change would
not be detected, but could be
biologically important 2. Yeast is not a
suitable model for humans? 3. Normal
cells are not responsive need for
some prior change (predisposition)?
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It is a characteristic of science that the full
explanations are often seized in essence by the
percipient scientist long in advance of any
possible proof. John D Bernal, The Origin of
Life, 1967
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Scientific Advisory Committee Dr MJ Crumpton
FRS ICRF Dr KM Brindle Cambridge U Prof PA
Jeggo Sussex U Prof RH Michell FRS Birmingham
U Prof PJ Hore Oxford U Prof H
Morgan Southampton U Dr CW Suckling FRS ICI
Prof JC Metcalfe Cambridge U Prof DT
Edmonds Oxford U Dr TM Dexter FRS Wellcome
Trust Prof KA McLauchlan FRS Oxford U Prof NC
Jones Manchester U Prof RA Dwek FRS Oxford
U Sir John Horlock FRS Open U Dr MJ
Owen GlaxoSmithKline Prof MD Waterfield
FRS Ludwig Institute Sir John Rowlinson
FRS Oxford U