HEALTH EFFECTS ASSOCIATED WITH HUMAN EXPOSURE TO RADIOFREQUENCY FIELDS

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HEALTH EFFECTS ASSOCIATED WITH HUMAN EXPOSURE TO
RADIOFREQUENCY FIELDS

• Jefferson County Commissioners
• John S. Reif
• Department of Environmental Health
• Colorado State University
• May 27, 1999

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HUMAN CANCERS MOST FREQUENTLY ASSOCIATED WITH
EXPOSURE TO 60 Hz MAGNETIC FIELDS

• Childhood leukemia - residential studies
• Brain cancer - occupational studies of persons
  working in industries with EMF exposures
• Leukemia - occupational studies of persons
  working in industries with EMF exposures

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CASE-CONTROL STUDIES OF CANCER IN ELECTRIC
UTILITY WORKERS

• Study of 19,904 male cancer patients, 1980-1984.
• Elevated leukemia risk for electrical workers,
  not present for other cancer sites.
• Overall leukemia risk was increased 62.
• Highest risks for radio and television repairers,
  (7.8), electricians (1.7), linemen (2.4), and
  power station operators (3.9).

Pearce, Reif, Fraser. Int J Epidemiol, 1989
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MAGNETIC FIELD EXPOSURE IN RELATION TO
LEUKEMIA AND BRAIN CANCER MORTALITY AMONG
ELECTRIC UTILITY WORKERS

• Study of 138,905 male workers employed at 5 large
  power companies, 1950-1986.
• Brain cancer risk was associated with total
  estimated exposure to magnetic fields.
• Brain cancer risk was 2.6 for the highest
  exposure category in the past 2-10 years.

Savitz et al. Am J Epidemiol, 1995
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OCCUPATIONAL ELECTRIC AND MAGNETIC FIELD EXPOSURE
AND BRAIN CANCER A META-ANALYSIS

• Combined analysis of 29 studies published through
  1995.
• Point estimate for 21 of 29 studies above 1.0
  (some evidence of increased risk).
• Pooled estimate for all 29 studies shows a 10 to
  20 percent increase in risk, statistically
  significant

Kheifets et al, J Occ Environ Med, 1995
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Radiation Exposure, Socioeconomic Status, and
Brain Tumor Risk in the U.S. Air Force

• Cohort study of male Air Force personnel
  1970-1989.
• Job exposure matrix to estimate exposure to ELF
  and RF.
• Personnel exposed to radiofrequency/microwave
  radiation had increased (1.39) risk of brain
  cancer
• Military rank associated with brain tumor risk.

Grayson, Am J Epidemiol, 1996
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BIOLOGICAL EFFECTS DEMONSTRATED WITH EXPOSURE TO
RF FIELDS

• Membrane effects cation transport, Ca efflux
• Signal transduction effects protein kinases,
  ornithine decarboxylase
• Cell proliferative responses and transformation
• cell cycle alterations
• Immune system studies lymphocyte cytotoxicity
• Nervous system studies Melatonin suppression
  (60 Hz), neurotransmitters, electrical activity
• 
  Repacholi, Bioelectromagnetics, 1998

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Studies of exposure to Broadcast and Military
Radio and TV towers
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Investigation of Increased Incidence in
Childhood Leukemia near Radio Towers in Hawaii

• Cluster evaluation of 12 children from the
  Waianae coast with acute leukemia 1979-1990.
• Cases occurred in vicinity of a military
  installation with low frequency radio towers
  (23.4 KHz).
• Leukemia incidence increased significantly
  (2.09)
• Leukemia mortality weakly associated with
  proximity to the towers within 2.6 miles.

Maskarinec et al, J Environ Path, Tox, Oncol 1994
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Cancer Incidence and Mortality and Proximity to
TV Towers (Australia)

• Ecological study of cancer incidence and
  mortality in municipalities surrounding North
  Sydney TV towers.
• Rates compared for 3 inner (TV tower) and 6 outer
  areas.
• Childhood leukemia incidence increased (1.58)
• Childhood leukemia mortality increased (2.32)

Hocking et al, Med J Australia, 1996
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Cancer Incidence Near Radio and Television
Transmitters in Great Britain Sutton Coldfield
Transmitter

• Cluster evaluation of cancer incidence for
  1974-1986. Risk of cancer measured in 4
  concentric rings up to 10 Km from transmitter,
• Acute leukemia risk was increased within 1.25
  miles of towers to 1.83 and declined with
  distance.
• Brain cancer risk also increased (1.3, ns)
• Findings not replicated in 20 transmitter study

Dolk et al, Amer J Epidemiol, 1997
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Colorado Department of Public Health and
Environment Study of Brain and Central Nervous
System Cancers in Residents Adjacent to the
Lookout Mountain Antenna Farm
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CDPHE Study of Brain and Central Nervous System
Cancers in Residents Adjacent to the Lookout
Mountain Antenna Farm

• June, 1998 Census Tract analysis was based only
  on cancer sites selected a priori
• Brain tumor O/E ratio for the entire tract was
  elevated (1.36)
• February, 1999 block group analysis shows
  statistically increased risks for men in BG 3
  with over 4 times as many malignant brain tumors
  as expected and for benign tumors in women in BG
  2 with over 5 times expected.

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CDPHE Study (Continued)

• February, 1999 block group analysis showed
  highest risk for brain cancer in men in area with
  highest exposures.
• Not all persons in BG 3 exposed - risk is
  underestimated
• A tight clustering of cases in time is not
  expected due to variations in exposure and
  latency
• Further study recommended (exposure assessment,
  other outcomes)

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CONCLUSIONS

• RF data base inadequate to assess causality
• CDPHE study of cancer incidence shows an
  association with male brain cancer in vicinity of
  Lookout Mountain, Jefferson county.
• Biological mechanisms have been demonstrated for
  60Hz and/or RF which could lead to increased
  cancer in humans.
• The evidence is adequate to dictate a cautionary
  approach and avoidance of any additional
  exposures to RF fields

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• We did not intend to imply in our review that
  radio frequency fields (RF) transmissions are not
  associated with cancer. We do not currently know
  whether such an association exists no one does.
  (April 26, 1999)
• 
  Michael A. McGeehin, PhD, MSPH
• Director (Acting)
• Division of Environmental Hazards and Health
  Effects
• National Center for Environmental Health
• Centers for Disease Control and Prevention
• Public Health Service, DHHS