Transcript REPRODUCTIVE AND DEVELOPMENTAL EFFECTS OF …

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
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
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
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
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
Radiation Exposure, Socioeconomic Status,
and Brain Tumor Risk in the U.S. Air Force
Cohort study of male Air Force personnel 19701989.
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
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
Studies of exposure to
Broadcast and Military
Radio and TV towers
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
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
Cancer Incidence Near Radio and
Television Transmitters in Great
Britain: Sutton Coldfield Transmitter
Cluster evaluation of cancer incidence for 19741986. 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
Colorado Department of Public
Health and Environment Study
of Brain and Central Nervous
System Cancers in Residents
Adjacent to the Lookout
Mountain Antenna Farm
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.
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)
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
“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