Powerlines & Cancer FAQs
John Moulder
Archive-name: medicine/powerlines-cancer-faq
Posting-Frequency: monthly
Last-modified: 17-June-2003
Version: 7.9.4
URL: http://www.mcw.edu/gcrc/cop/powerlines-cancer-faq/toc.html
Copyright: (c) 1993-2003 John E. Moulder & The Medical College of
Wisconsin
Maintainer: John E. Moulder <jmou...@mcw.edu>
** Frequently Asked Questions (FAQs) on Power-Frequency Fields (EMF)
and Cancer
**Summary**
Questions and Answers on the connection between power lines, electrical
occupations and cancer: discussion of the biophysics of interactions
with EM sources, summaries of the laboratory and human studies,
information on standards, and a bibliography.
Most of the concern about power lines ("EMF") and cancer stems from
studies of people living near power lines (Question 12) and people
working in "electrical" occupations (Question 15). Some of these
studies appear to show a weak association between exposure to
power-frequency magnetic fields and the incidence of cancer.
However, epidemiological studies done in recent years show little
evidence that power lines are associated with an increase in cancer
(Question 19), laboratory studies have shown essentially no evidence of
a link between power-frequency fields and cancer (Question 16), and a
connection between power line fields and cancer remains biophysically
implausible (Question 18).
A 1996 review by the U.S. National Academy of Science concluded that:
"No conclusive and consistent evidence shows that exposures to
residential electric and magnetic fields produce cancer, adverse
neurobehavioral effects, or reproductive and developmental
effects."(Question 27E)
A 1999 review by the U.S. National Institutes of Health concluded that:
"The scientific evidence suggesting that [power-frequency
electromagnetic field] exposures pose any health risk is
weak."(Question 27G).
A 2001 review by the U.K. National Radiation Protection Board (NRPB)
concluded that:
"Laboratory experiments have provided no good evidence that extremely
low frequency electromagnetic fields are capable of producing
cancer, nor do human epidemiological studies suggest that they cause
cancer in general." (Question 27H)
A 2001 review of the epidemiological literature by the International
Commission on Non-Ionizing Radiation Protection concludes that:
"In the absence of evidence from cellular or animal studies, and
given the methodological uncertainties and in may cases
inconsistencies of the existing epidemiologic literature, there is
no chronic disease for which an etiological [causal] relation to
[power-frequency fields] can be regarded as established."
The largest studies of childhood leukemia and power lines ever done
reported in 1997-2000 that they could find no significant evidence for
an association of power lines with childhood leukemia (Q19H through
19K). In contrast, two studies published in 2000 reported that if all
the studies for which magnetic fields were measured (or could be
calculated) were pooled, a statistically significant association could
be found for childhood leukemia in the children with the highest
average fields.
On the other hand, a series of studies have shown what life-time
exposure of animals to intense power-frequency magnetic fields does not
cause cancer or any other health problems. (Q16B)
Overall, most scientists consider the evidence that power line fields
cause or contribute to cancer to be weak to nonexistent.
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The full version of this FAQ is available on the web at:
http://www.mcw.edu/gcrc/cop/powerlines-cancer-faq/toc.html
NOTE THAT "faq" is lower-case. UPPER-CASE MAY OR MAY NOT WORK
The USENET version contains only the Table of Contents and a list of
recent revisions.
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Preguntas y respuestas sobre líneas electricas y cancer esta disponible
en espanol:
http://www.mcw.edu/gcrc/cop/lineas-electricas-cancer/toc.html
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There are two related FAQs:
FAQs about Cell Phone Base Antennas and Human Health
http://www.mcw.edu/gcrc/cop/cell-phone-health-faq/toc.html
Static Electromagnetic Fields and Cancer FAQs
http://www.mcw.edu/gcrc/cop/static-fields-cancer-faq/toc.html
NOTE THAT "faq" IS lower case. UPPER CASE MAY OR MAY NOT WORK
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** Revisions Notes
(v7.9, May/June 2003):
- Blood cells were exposed to a 800 microT 60-Hz field for 24 hours
and/or to a chemical mutagen; no evidence of genotoxic injury was
found for the field alone, but exposure to the field enhanced the
genotoxicity caused by the chemical [G118].
- Blood cells were exposed to a 230-700 microT 50-Hz fields for 12
hours and/or to gamma irradiation; no evidence of genotoxic injury
was found for the field alone, and exposure to the field did not
enhance the chromosome injury caused by the ionizing radiation
[G119].
- A study of men with both occupational and residential exposure to
power-frequency fields found no effects of the exposure on melatonin
levels [E43].
- Calculated residential magnetic field exposure was associated with
melanoma in women, but not in men; estimated occupational magnetic
field exposure was not associated with melanoma [C65].
- Occupational exposure to power-frequency magnetic fields was
associated with prostate cancer [D52].
- Human cancer cells were exposed to 2000- 13000 microT fields at 50Hz
for 2 or 4 days; above 6000 microT cell division was inhibited and
cell death was increased [H70].
- Exposure of human white blood cells to 80 or 800 microT 50-Hz fields
did not cause genotoxic injury, and did not significantly enhance
genotoxic injury produced by a genotoxic drug; but the 800 microT
exposure showed some evidence for enhancement of cell division
[G117].
- Exposure of pregnant rats to 5-500 microT 60-Hz fields for 6-20 days
had no effect on the mothers or on the offspring [J31].
(v7.8, Jan/Feb-2003):
- Occupational exposure to power-frequency fields was associated with
brain cancer, but only if there was also exposure to lead, solvents
or pesticide/herbicides [D51].
- Exposure to power line electric fields in the UK was not
associated with the incidence of childhood cancer [C64].
- Residence near powerlines in Norway was not associated with an
increased risk of birth defects [J30].
- Exposure to a 2000 microT field for 52 weeks did not promote skin
cancer in rats [G116].
- Exposure of human volunteers to power-frequency fields had no
effect on nighttime secretion of melatonin or other hormones [E35].
- Exposure of human immune system cells to 2-500 microT fields had
no effects on their function [H69].
- Exposure of cultured cells to a 1000 microT field caused DNA
stand breaks if the exposure was intermittent, but not if the
exposure was continuous [G115].
- Two studies of electrical utility workers found no evidence that
exposure to power-frequency fields was associated with heart
disease [E37, E38].
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** Table of Contents
1. Is there a concern about power lines and cancer?
2. What is the difference between the electromagnetic (EM) energy
associated with power lines and other forms of EM energy such as
microwaves or x-rays?
3. Why do different types of EM sources produce different biological
effects?
4. What is difference between EM radiation and EM fields?
5. Do power lines produce EM radiation?
6. How do ionizing EM sources cause biological effects?
7. How do RF and MW sources cause biological effects?
8. How do the power-frequency EM fields cause biological effects?
9. Do non-ionizing EM sources cause non-thermal as well as thermal
effects?
10. What sort of power-frequency fields are common in residences and
workplaces?
11. Can power-frequency fields in homes and workplaces be reduced?
12. What is known about the relationship between power line corridors
and cancer rates?
13. How big is the "cancer risk" associated with living next to a power
line?
a. What is the risk of cancer in general?
b. What is the risk of childhood leukemia?
14. How close do you have to be to a power line to be considered exposed
to power-frequency magnetic fields?
15. What is known about the relationship between electrical occupations
and cancer rates?
16. Do laboratory studies indicate that power-frequency fields can cause
cancer?
a. Do power-frequency fields show genotoxic activity in humans?
b. Do power-frequency fields cause cancer in animals?
c. Do power-frequency fields show genotoxic activity in cell
culture?
d. Do power-frequency magnetic fields cause or enhance neoplastic
cell transformation?
e. Are power-frequency magnetic fields cancer promoters?
f. Do power-frequency magnetic fields enhance the effects of other
genotoxic agents?
17. Do laboratory studies indicate that power-frequency fields have any
biological effects that might be relevant to cancer?
a. How do lab studies of the effects of power-frequency fields on
cell and tumor growth relate to the question of cancer risk?
b. How do lab studies of the effects of power-frequency fields on
immune function relate to the question of cancer risk?
c. How do lab studies of the effects of power-frequency fields on
melatonin relate to the question of cancer risk?
18. Do power-frequency fields show any reproducible biological effects
in laboratory studies?
a. Do power-frequency fields of the intensity encountered in
occupational and residential settings show reproducible
biological effects?
b. Are there known mechanisms by which power-frequency fields of the
intensity encountered in occupational and residential settings
could cause biological effects?
c. Haven't some new mechanisms been proposed that could explain how
power-frequency magnetic fields could cause biological effects?
d. Could the presence of transients or harmonics in power-frequency
fields provide a biophysical mechanism for biological effects?
19. What about the "new studies" showing a link between power-frequency
fields and cancer?
a. What about the European (Scandinavian) epidemiological studies
showing a link between power lines and cancer?
b. What about the studies showing a link between occupational
exposure to power-frequency fields and cancer?
c. What about the studies showing a link between electrical
occupation and breast cancer?
d. What about the studies showing a link between pulsed electric
fields and lung cancer?
e. What about the studies linking the use of electrical appliances
with cancer?
f. What about Sweden's/Denmark's decision to regulate fields power
line fields?
g. What about the study showing that it is the interaction between
power- frequency fields and the Earth static field that causes
cancer?
h. What about the 1997 NCI study showing no link between power lines
and childhood leukemia?
j. What about the 1999 Canadian studies of power lines and childhood
leukemia?
k. What about the 1999-2000 UK studies of power lines and childhood
leukemia?
l. Could exposure to power-frequency electric rather than magnetic
fields be linked with cancer?
20. What criteria do scientists use to evaluate all the laboratory and
epidemiologic studies of power-frequency magnetic fields and
cancer?
a. Criterion One: How strong is the association between exposure to
power-frequency fields and the risk of cancer?
b. Criterion Two: How consistent are the studies of associations
between exposure to power-frequency fields and the risk of
cancer?
c. Criterion Three: Is there a dose-response relationship between
exposure to power-frequency fields and the risk of cancer?
d. Criterion Four: Is there laboratory evidence for an association
between exposure to power-frequency fields and the risk of
cancer?
e. Criterion Five: Are there plausible biological mechanisms that
suggest an association between exposure to power-frequency fields
and the risk of cancer?
21. If exposure to power-frequency magnetic fields does not explain the
residential and occupations studies which show increased cancer
incidence, what other factors could?
a. Could problems with dose assessment affect the validity of the
epidemiologic studies of power-frequency fields and cancer?
b. Are there other cancer risk factors that could be causing a false
association between power-frequency fields and cancer?
c. Could the epidemiologic studies of power-frequency fields and
cancer be biased by the methods used to select control groups?
d. Could analysis of the epidemiologic studies of power-frequency
fields and cancer be skewed by publication bias?
e. Could analysis of the epidemiologic studies of power-frequency
fields and cancer be biased by multiple-comparison artifacts?
f. Does the evidence that childhood leukemia has an infectious basis
mean that the weak association sometimes seen between power-
frequency fields and childhood leukemia is an artifact?
22. What is the strongest evidence for a connection between power-
frequency fields and cancer?
23. What is the strongest evidence against a connection between power-
frequency fields and cancer?
24. What studies are needed to resolve the cancer-EMF issue?
25. Is there any evidence that power-frequency fields cause any effects
on human health, such as miscarriages, birth defects, Alzheimer's
disease, multiple sclerosis, suicide or sleep disorders?
26. What are some good overview articles?
27. Are there exposure guidelines for power-frequency fields?
a. What are there guidelines for power-frequency field exposure of
the general public?
b. What are there guidelines for occupational power-frequency
field exposure?
c. Are there special exposure guidelines for people with cardiac
pacemakers
d. Is a US government agency about to recommend strict limits on
occupational and residential exposure to power-frequency fields?
e. What does the 1996 report from the U.S. National Research Council
say?
f. Does a 1998 report from the U.S. National Institute of
Environmental Health Sciences (NIEHS) say that power-frequency
fields are a "possible" carcinogen?
g. What does the 1999 report from the U.S. National Institute of
Environmental Health Sciences (NIEHS) to the US Congress say
about power-frequency fields and cancer?
h. What does the 2001 report from the U.K. National Radiation
Protection Board (NRPB) say about power-frequency fields and
cancer?
j. Does a 2002 report from the International Agency for Research on
Cancer (IARC) say that power-frequency fields are a "possible"
carcinogen?
k. What does the 2002 report from the State of California say about
possible human health hazards from exposure to power-frequency
fields?
28. What effect do power lines have on property values?
29. What equipment do you need to measure power-frequency magnetic
fields?
30. How are power-frequency magnetic fields measured?
31. Do the issues discussed in this FAQ sheet apply to EM fields other
than power-frequency fields?
a. Low-frequency fields other than sinusoidal power-frequency
fields
b. Static electric and magnetic fields
c. Radiofrequency and microwave frequencies
32. What about the new study claiming that radon exposure is increased
by the presence of electromagnetic fields.
33. What about the reports that some people are sensitive to (allergic
to) the presence of electromagnetic fields?
34. Should I buy a house next to a power line?
35. Who wrote this FAQ?
** Bibliography
1. Recent Reviews of the Biological and Health Effects of Power-
Frequency Fields
2. Reviews of the Epidemiology of Exposure to Power-Frequency Fields
3. Epidemiology of Residential Exposure to Power-Frequency Fields
4. Epidemiology of Occupational Exposure to Power-Frequency Fields
5. Human Studies Related to Power-Frequency Exposure and Cancer
6. Biophysics and Dosimetry of Power-Frequency Fields
7. Laboratory Studies of Power-Frequency Fields and Cancer
8. Laboratory Studies Indirectly Related to Power-Frequency Fields and
Cancer
9. Studies of Power-Frequency Fields and Reproductive Toxicity
10. Reviews of Laboratory Studies of Power-Frequency Fields
11. Miscellaneous Items
12. Regulations and Standards for Ionizing and Non-ionizing EM Sources.