“Health Concerns with Electromagnetic and Electrostatic Field
Transcript of “Health Concerns with Electromagnetic and Electrostatic Field
Page1
“Health Concerns with Electromagnetic and Electrostatic Field
Exposure” EE205
Health & Safety Fall 2013
Denard Lynch REFERENCES: 1
Page2
Electromagnetic Fields and Public Health (def’ns)
ò Electromagnetic waves are characterized by their: wavelength, frequency, energy
ò Affect on biological systems is determined by ò Intensity of field ò Amount of energy per photon (prop. to freq.)
ò EM waves at low freq.: electromagnetic fields ò EM waves at high freq.: electromagnetic radiation
ò Ionizing radiation: has enough photon energy to break atomic bonds
ò Non-ionizing radiation: refers to all other EM radiation where photon energy can’t break atomic bonds.
ò NOTE: even high intensity NIR can’t cause ionization!
REFERENCES: 14, 17 2
Page3
Biological Effects…
ò “Biological Effect” is when exposure to EM fields causes a detectable change in the biological system
ò “Adverse Health Effect” is when biological effect can’t normally be compensated for by the biological system (e.g. human body)
ò Some biological effects are innocuous, even beneficial; some are immediately or potentially harmful
REFERENCES: 17 3
Page4
Biological Effects…(cont’d)
ò Fields at freq > 1MHz primarily cause heating
ò At lows levels, heat is handled by normal thermoregulatory processes
ò At high levels, thermal damage may accrue (eg. Microwave oven)
ò Other effects have been reported but not scientifically established
REFERENCES: 14, 15, 17 4
Page5
Biological Effects…(cont’d)
ò Fields at freq < 1MHz primarily induce electric charges and currents
ò Low levels have no established effect
ò High levels may interfere with electro-neural systems ò Other effects (e.g. cancer, memory loss) have also been
reported but not established.
REFERENCES: 14, 15, 17 5
Page6
ò Exist when V exists; Don’t penetrate body
ò Cause charge buildup; Induce currents
ò Static has little effect if no “discharge” (e.g. lightning) or unless very intense
ò ELF leads to mostly electrostatic heating REFERENCES:
Electric Fields
15
Page7
Magnetic Fields
ò Exist when I flows; Easily penetrate body
ò “magnetizes” body; induces currents
ò Static: minimal effect unless very intense
ò ELF: mostly heating effect due to joule heating from induced currents
REFERENCES: 15 7
Page8
Electromagnetic Fields and Public Health
ò International Electric and Magnetic Fields (EMF) Project
ò Launched by World Health Organization (WHO) ò Objective: arrive at scientifically sound recommend’s
for health risk assessment of exposure to static and time-varying electric and magnetic fields
ò Includes static (0Hz), extremely low freq. (ELF, <300Hz), Intermediate Freq. (IF, 300Hz – 10MHz), and radio freq. (RF, 10MHz – 300GHz).
REFERENCES: 16 8
Page9
What they do… ò Review scientific literature ò Identify gaps in knowledge ò Focus research ò Formally assess health risks of EMF exposure ò Encourages international standards ò Provides info on perception, communication,
management of risk ò Advises national programs and non-gov institutions
REFERENCES: 16 9
Page10
How they do it…
ò Project overseen by International Advisory Committee (IAC)
ò Many participating international org’s
ò Scientific work done by International Commission on Non-Ionizing Radiation Protection (ICNIRP) and independent WHO collaborating institutions.
REFERENCES: 16 10
Page11 REFERENCES: 14
104 104
104
11
Page12 REFERENCES: 14
104
104
12
Page13 REFERENCES: 26
Page14
Recent Results….
ò IARC evaluation completed 2001, published 2002
ò ELF magnetic fields ELF magnetic fields classified as 2B: Possible Carcinogen
ò based on limited evidence from epidemiological studies of childhood leukaemia
ò other data inadequate
ò 2B: other explanations possible
REFERENCES: 25, 26 14
Page15 REFERENCES: 25, 26 15
Page16
Recent Results continued…
ò RFReview (2009)(Ref.29)
ò “Thermally significant RF exposure can impair male fertility and cause increased embryo and fetal losses and increase the incidence of fetal malformations and anomalies.”(p260)
ò “Cataract in the eyes of anesthetized rabbits remains a well-established thermal effect of RF exposure. However, primates appear less susceptible to cataract induction than rabbits, and opacities have not been observed in primates following either acute or prolonged exposure.”(p260)
ò “…the plausibility of various non-thermal mechanisms that have been proposed is very low.”(p260)
REFERENCES: 16 29
Page17
ò “260 the reported RF radiation induced changes are very small and of limited functional consequence.”(p360)
ò “…some evidence of small changes in brain physiology, …of limited functional consequence; no changes were seen in cognitive function.)(p261)
ò “…evidence from double-blind provocation studies suggests that subjective symptoms, such as headaches, … identified by some individuals [from] RF exposure, whilst real enough to the individuals concerned, are not causally related to EMF exposure.”(p261)
ò “The experimental data do not suggest so far that children are more susceptible than adults to RF radiation, but few relevant studies have been conducted.”(p261)
ò Studies of the effects of RF modalities such as high peak power pulses have been somewhat diverse and sporadic; no effects have been seen other than those associated with heating and with acoustic perception.
REFERENCES: 17 29
Page18 REFERENCES:
Typical Values of EMF
Page19 REFERENCES:
Customer Looking at New Lot
Page20 REFERENCES:
Customer Looking at New Lot
Page21 REFERENCES:
Customer Looking at New Lot
25 mG
Recall: 1T = 10,000G; 25mG = 2.5T
Page22 REFERENCES:
Customer Looking at New Lot
12 mG
Page23 REFERENCES:
Customer Looking at New Lot
8 mG
Page24 REFERENCES:
Customer Looking at New Lot
3 mG
Page25 REFERENCES:
Customer Looking at New Lot
1.2 mG
Page26 REFERENCES:
Existing House
Page27 REFERENCES:
Existing House
2 - 5 mG
Page28 REFERENCES:
Typical House
0.2 - 2 mG
Page29 REFERENCES:
Appliance EMF
25 mG
Page30 REFERENCES:
Appliance EMF
1 - 3 mG
Page31 REFERENCES:
Appliance EMF
3000 mG
Page32 REFERENCES:
Appliance EMF
:30
100 mG
Page33 REFERENCES:
Appliance EMF
:30
10 mG
Page34 REFERENCES:
Equipment EMF
50-300mG
Page35 REFERENCES:
Equipment EMF
2-30mG
Page36 REFERENCES:
Typical Ranges of Magnetic Fields
0.3 - 13 mG 30 m
Page37 REFERENCES:
Typical Ranges of Magnetic Fields
0.3 - 13 mG
0.1 - 3 mG 15 m
30 m
Page38 REFERENCES:
Typical Ranges of Magnetic Fields
0.1 - 11 mG
Page39 REFERENCES:
Typical Ranges of Magnetic Fields
5 - 1000 mG (2' away)
0.1 - 11 mG
Page40 REFERENCES:
Typical Ranges of Magnetic Fields
5 - 1000 mG (2' away)
0.1 - 11 mG
0.2 - 30 mG
Page41
People love their Cell Phones…
REFERENCES: 26 41
Page42 REFERENCES: 26, 27
Page43 REFERENCES:
Page44
ò SAR Distributions for 3 sizes of Scaled Human Bodies at 900MHz
REFERENCES:
Page45 REFERENCES: 26
Page46 REFERENCES: 26
Page47
Summary ò No argument that unwanted exposure to extreme levels can
have negative health effects
ò For “normal” levels, heating is the basis for current guidelines
ò Other effects may accrue with long-term exposure to low levels, but have not yet been scientifically established
REFERENCES: 47
Page48 REFERENCES:
REFERENCES: 1. water.usgs.gov/admin/memo/QW/qw92.01.html
(American Society for Testing & Materials, 1990 Annual Book of ASTM Standards, Section 11, “Water and Environmental Technology”, Designation: D 1193 –77, p. 45 – 47)
2. www.ceramaseal.com/reference/dielectric.cfm 3. www.isi-seal.com/Technical_Info/Tech_Dielectric_Strength.htm 4. “Physics for Scientists & Engineers”, 3rd Ed., Raymond A. Serway, Saunders College Publishing 1990 5. accept.la.asu.edu/courses/phy110/ds/appendixC.html 6. www.occuphealth.fi/e/info/anl/395/kitumb.htm 7. www-training.llnl.gov/wbt/hc/Electrical/Accident.html 8. www.prl.ernet.in/~bobra/EARTH/html1/chapt3.htm 9 www.osha-slc.gov/SLTC/constructionelectrical/electrical_incidents/eleccurrent.html 10. www-training.llnl.gov/wbt/hc/Electrical/GFCIworks.html 11. www.osha-slc.gov/SLTC/constructionelectrical/electrical_incidents/powertools.html 12. www.jlab.orh/ehs/manual/EHSbook-392.html 13. www.physics.udel.edu/wwwusers/watson/scen103/colloq2000/safety.html 14. ICNIRP Guidelines – “GUIDELINES FOR LIMITING EXPOSURE TO TIME-VARYING ELECTRIC, MAGNETIC AND ELECTROMAGNETIC FIELDS (up to 300 GHz) 15. www.who.int/peh-emf/publications/What_is_EMF/section2.htm 16. www.who.int/peh-emf/publications/facts_press/efact/efs181.html
(Electromagnetic Fields and Public Health: The International EMF Project, Fact Sheet N181) 17. www.who.int/peh-emf/publications/facts_press/efact/efs182.html
(Electromagnetic Fields and Public Health: The International EMF Project, Fact Sheet N182) 18. University of Guelph – Safety Policy Manual, Policy 851.07.13 19. www.statpower.com/tech4-1.htm 20. www.argo.ca/p11_circuit_breakers_.html 21. www.stayhealthy.com/profiles/bc1_how.cfm 22. “Electrical Detection of Acupuncture Points”, N. Barlea, H. Sibianu, R. V. Ciupa
(http://bavaria.utcluj.ro/~mbirlea/m/04m.htm)
48
Page49 REFERENCES:
23. www.nasatech.com/Briefs/Apr00/MSC22491.html 24. members.tripod.com/~StormTrooper_2/index2.htm 25. “Electromagnetic Fields and Public Health, Extremely low frequency fields and cancer”, International EMF Project, Fact Sheet No 263 26. “WHO’s International EMF Project and results so far”, presentation by Dr MH Repacholi, Co-ordinator, Radiation and Environmental Health, World Health Organization, Geneva, Switzerland ~2005 27. “Electromagnetic Fields and Public Health, Mobile Telephones and their Base Stations”, International EMF Project, Fact Sheet No 193 28. “RF Sources – Why are Cell Phones Special?”, James C. Lin, U of Illinois, presentation to ICNORP Rio Brazil, Oct. 2008 29. “RFReview: Exposure to high frequency electromagnetic fields, biological effects and health consequences (100 kHz-300 GHz) ”, Paolo Vecchia, Rüdiger Matthes, Gunde Ziegelberger James Lin, Richard Saunders, Anthony Swerdlow, ICNIRP 16/2009, retreived from http://www.icnirp.org/PubEMF.htm Mar 21, 2010 30. “Electromagnetic fields and public health Exposure to extremely low frequency fields”, Fact Sheet #322, World Health Organization, 2006, retrieved from http://www.who.int/mediacentre/factsheets/fs322/en/print.html, Mar 21, 2010
49