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, 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, 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 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 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 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  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 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 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 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