Cell Phones and Human Health: An Update on Research and Regulations

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Cell Phones and Human Health An Update on
Research and Regulations

• Presented at AIHCE June 6, 2001
• Marty Eroh, CIH
• Pinnacle West Corporation
• martin.eroh_at_pinnaclewest.com

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Cell Phone - Background

• Use of cell phones has grown dramatically over
  the last fifteen years.
• Operate at frequencies slightly higher than TV
  and FM Radio signals (Nonionizing).
• Analog and digital phones operate in the
  frequency range of 900 - 1800 MHz.
• The maximum powers of these phones are 2W and 1W
  (900 and 1800 MHz respectively). Average power
  are 1/8 of maximum.

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EM Spectrum
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Basic Operation

• Mobile phones communicate with base stations
  (fixed installations).
• Base stations have limited range, therefore
  requires a nationwide network.
• Macrocells - up to about 22 miles, power output
  in tens of watts.
• Microcells - infill, airports, railway stations.
  Range of few hundred yards.
• Picocells - Sited inside buildings. Low power.

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Sources of Exposure

• Mobile phones and base stations - exposures
  reduce with distance from the source.
• Mobile phones - principal exposure is to the side
  of the head for hand held, or to other body parts
  during hands free use.
• Base station exposure is whole body, but much
  lower intensity than from handsets.

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Typical and Atypical Base Stations
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Typical and Atypical Base Stations
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Typical and Atypical Base Stations
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Typical and Atypical Base Stations
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Typical and Atypical Base Stations
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Typical and Atypical Base Stations
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Current Basis of Exposure Guidelines

• Primary sources of exposure guidelines, including
  IEEE, ICNIRP, NRPB are all based on avoiding
  thermal effects.
• Some variation in the limits, e.g. some limits
  build in a safety factor for the general public
  vs workers.

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Exposure Limits (cont.)

• Most exposure limits are now provided in two
  forms
• Basic Restrictions - based on SAR - difficult to
  measure.
• Reference or Investigation Levels - based on
  field strengths (v/m, A/m, or W/m2), more easily
  measured.
• Can exceed the reference levels as long as the
  basic restrictions are not exceeded.

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Example of ICNIRP Guidelines

• Basic restrictions
• Whole Body SAR 0.4 (0.08) W/kg averaged over 6
  minutes.
• Head / trunk SAR 10 (2) W/kg based on 10 grams
  of mass and 6 minute average.
• ( ) denotes public.

• Reference level for general public at cell phone
  frequency
• 1800 - 1900 MHz 9 - 9.5 W/m2 (based on f in
  MHz/200)

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Are there Non-thermal Effects?

• Is there justification for standards below
  thermal limits?
• Do biological effects adverse health effects?
• What areas of research deserve attention?
• What approach should be taken while research is
  being completed?

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IEGMP

• Independent Expert Group on Mobile Phones report
  from Great Britain, April 2000.
• Good overall summary of the science to date.
• Review this report and a few more recent
  publications.

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IEGMP Overall Conclusions

• Despite widespread use, there is little research
  specifically relevant to cell phones.
• The balance of evidence to date suggests that
  there are no adverse health effects below current
  ICNIRP guidelines (only thermal effects).
• Some evidence for biological activity below the
  guidelines, but not clear that they lead to
  disease.

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IEGMP Overall Conclusions (Cont.)

• Not possible to say that exposures below
  guidelines are totally without potential adverse
  health effects knowledge gaps justify
  precautionary approach.
• Due to well-documented detrimental effects
  drivers should be dissuaded from using either
  hand-held or hands-free phones while on the move.

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Biological Interaction

• Force produced by an electric field on charged
  objects (ions in the body) causes them to move,
  results in electric currents. Currents flowing
  through resistance of the material results in
  heating. Heat input causes increased blood flow
  for heat dissipation (equilibrium).
• Increase in brain temp by cell phones is
  estimated to be 0.1 C (to equilibrium).

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Biological Interaction

• The energy quanta at cell phone frequencies is 4
  - 7 micro eV (millionth of eV). Energy needed to
  break chemical bonds in DNA is 1 eV.
  Insufficient power to break bonds.
• Electric field created in biological tissue. But
  to produce detectable changes, these fields would
  need to be greater than thermal or random noise.

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Potential Biological Interaction

• Could fields induce cell polarization?
• Could fields affect movement of ions through cell
  membrane channels?
• Does it increase ODC Activity?
• Do fields effect gene expression?
• Others?
• If any of these effects are real, do they result
  in an adverse health outcome?

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Epidemiologic Evidence

• Few studies directly examining cell phones and
  health effects.
• Latency of certain diseases, changes in
  technology, and changes in usage patterns, is an
  overall weakness in cell phone epidemiology.

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Two Recent Hospital Based Case-Control Studies

• Muscat et al., JAMA 2000 2843001-7
• Inskip et al., NEJM, 2001344 79-86
• 469 and 782 cases of brain CA respectively.
• Controls were either benign disorders or cancers
  other than lymphoma and leukemia.
• Exposure assessment through questionnaire.
• Duration and frequency of use.
• Type of phone, handedness

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Results of Muscat and Inskip

• No association between measures of cell phone use
  and risk of brain cancer (total, site specific,
  or by histological type).
• Limitations
• Exposure assessment (questionnaire)
• No measurements
• Low usage / short latency
• Hospital controls

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Cohort Study in Denmark

• Johansen et al., Journal of the NCI, 2001
• Nationwide cohort study of cell phone users.
• Linked to Danish cancer registry.
• Standardized Incidence Ratios (SIR) - observed to
  expected.

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Denmark Study - Results

• No excess risk of any cancers. Example SIRs.
• All cancers 0.86 (men), 1.03 (women)
• Brain / nervous system 0.95 (m), 1.03 (w)
• Salivary gland 0.78 (m), 0 cases in women
• Leukemia 0.97 (m), 1.07 (w)

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Recommended Research (IEGMP)

• Epidemiologic studies. Case control and cohort.
  Particularly due to latency and changes in
  technology.
• Studies of brain function.
• Consequences of exposures to pulsed fields.
• Subcellular and cellular research.
• Improved exposure assessment
• 5050 funding, independent panel

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IEGMP Precautionary Approach

• Prefer the two-tiered approach to exposure limits
  - general public versus workers, or controlled
  versus uncontrolled environments.
• Establishment of exclusion zones around base
  stations where exposure guidelines may be
  exceeded.
• Signs on micro and picocell transmitters stating
  do not open when in use.

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IEGMP Precautionary (cont.)

• More open process in the siting of base stations.
• Pursue a policy of mast sharing and roaming where
  practical to minimize base stations.
• Provide information on SAR to mobile phone
  consumers.

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IEGMP Precautionary (cont.)

• Non-essential use of cell phones by children
  should be discouraged.
• Drivers should be dissuaded from using any type
  of cell phone while moving.

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Cautious Inaction

• Trichopoulos from Harvard and Adami from
  Karolinska Institute, Editorial in NEJM
• Discussing radio-frequency energy stated
• the lack of a theoretical foundation and the
  absence of empirical evidence of a substantial
  increase in risk legitimize cautious inaction,
  unless and until a small excess risk is firmly
  documented.

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SUMMARY

• Known Risks
• Heating - existing standards are protective.
• Use of cell phone while driving.
• Need For Further Research - Potential non-thermal
  effects and long term epidemiology.
• In the interim Precautionary Approach or
  Cautious Inaction.

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Regulatory / Exposure Guidance

• FCC
• 47 C.F.R., Part 1 Subpart I (1.1301 - 1.1319)
  NEPA
• 47 C.F.R.,Part2 Subpart J (2-1091 - 2-1093) RF
  Exposure, Mobile and Portable Devices
• OET Bulletin 65, Evaluating Compliance with FCC
  Guidelines for Human Exposure to RF EMF, 8/97
  (http//www.fcc.gov/oet/rfsafety)
• OET Bulletin 56, QA About the Biological Effects
  Potential Hazards of RF EMF.

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Regulatory / Exposure Guidance (cont.)

• IEEE C95.1-1991 (1999 Edition), IEEE Standard for
  Safety Levels with Respect to Human Exposure to
  Radio Frequency Electromagnetic Fields, 3 kHz to
  300 GHz
• IEEE C95.2-1999, IEEE Standard for Radiofrequency
  Energy and Current Flow Symbols
• IEEE C95.3-1991, IEEE Recommended Practice for
  the Measurement of Potentially Hazardous
  Electromagnetic Fields - RF and Microwave

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Selected Bibliography

• Adey, WR et al. Spontaneous and
  nitrosoursea-induced primary tumors of the
  central nervous system in Fischer 344 Rats
  exposed to frequency modulated microwave fields.
  Cancer Research, 60 1857-1863, 2000.
• Elwood JM. A Critical Review of Epidemiologic
  Studies of Radiofrequency Exposure and Human
  Cancers. Environ Health Perspectives, 1999107
  (suppl 1) 155-168

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Selected Bibliography (Cont.)

• Inskip, PD et al. Cellular telephone use and
  brain tumors. New England Journal of Medicine,
  January 11, 2001.
• Inskip, PD. Frequent radiation exposures and
  frequency-dependent effects the eyes have it.
  Epidemiology, 12(1)1-4, 2001.
• Johansen, C et al. Cellular telephones and cancer
  a nationwide study in Denmark. Journal of the
  National Cancer Institute, 93(3) 203-07, 2001.

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Selected Bibliography (Cont.)

• Lai, H Singh, NP. Acute low-intensity microwave
  exposure increases DNA single-stranded breaks in
  rat brain cells. Bioelectromagnetics
  16(3)207-210, 1995.
• Lai, H Singh, NP. DNA single- and double-strand
  DNA breaks in rat brain cells after acute
  exposure to low-level radiofrequency
  electromagnetic radiation. International Journal
  of Radiation Biology, 69513-521, 1996.

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Selected Bibliography (Cont.)

• Krewski, D et al. Potential health risks of
  radiofrequency fields from wireless
  telecommunications. Journal of Toxicology
  Enviornmental Health Part B Critical reviews,
  4(1) 1-143, 2001.
• Krewski, D et al. Recent advances in research on
  radiofrequency fields and health. Journal of
  Toxicology Enviornmental Health Part B
  Critical reviews, 4(1) 145-159, 2001.

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Selected Bibliography (Cont.)

• Morgan, RW et al. Radiofrequency exposure and
  mortality from cancer of the brain and
  lymphatic/hematopoietic systems. Epidemiology,
  vol. 11(2) 118-27, 2000.
• Moulder, JE et al. Cell phones and cancer what
  is the evidence for a connection? Radiation
  Research 151(5) 513, 1999.
• Muscat, JE et al. Handheld cellular telephone
  use and risk of brain cancer. JAMA, 284(23)
  3001-7, 2000.

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Selected Bibliography (Cont.)

• Park, RL. Cellular telephones and cancer how
  should science respond? Journal of the National
  Cancer Institute, 93(3) 166-67, 2001.
• Repacholi, M et al. Lymphoma incidence in
  Eu-PIM-1 transgenic mice exposed to 50 Hz
  magnetic fields for up to 18 months experimental
  methodology and exposure system. 17th Annual
  Meeting of the Bioelectromagnetics Society, June
  18-22, Boston, MA, 1995.

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Selected Bibliography (Cont.)

• Stang, A et al. The possible role of
  radiofrequency radiation in the development of
  uveal melanoma. Epidemiology, 127-12, 2001.
• Sienkiewicz, ZJ et al. Low level exposure to
  pulsed 900 MHz microwave radiation does not cause
  deficits in the performance of a spatial learning
  task in mice. Bioelectromagnetics, vol. 21
  151-158, 2000.

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Selected Bibliography (Cont.)

• Stewart, W. Mobile phones and health.
  Independent Expert Group on Mobile Phones (IEGMP)
  // Website http//www.iegpm.org.uk/IEGMPtxt.htm/
  /
• Vijayalaxmi et al. Cytogenetic studies in human
  blood lymphocytes exposed in vitro to
  radiofrequency radiation at a cellular telephone
  frequency ( 835.62 Mhz, FDMA) Radiation research,
  155 113-121 2001

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Selected Bibliography (Cont.)

• Inquiry into Electromagnetic Radiation,
  Parliament of the Commonwealth of Australia,
  Report of the Senate Environment, Communications,
  Information Technology and the Arts References
  Committee, May 2001, http//www.aph.gov.au/senate/
  committee/ecita ctte/EMR/contents.htm