An investigation into the vector ellipticity of extremely low frequency magnetic fields from appliances in UK homes
The biological effects of EM field ellipticity have been getting a closer look recently. Ellipticity is a measure of how much a field's direction of polarization curves in space. This is mostly likely another reason why those with ES have different reactions to different field sources even at similar average fields strengths. I'm submitting this email to continue building our archive of scientific reviews and assist those who use this group's collective experience and findings for research.
-Beau
ps. Note, it was found that ovens, both standard and microwave, generated fields with very high ellipticities compared to other appliances. This could explain those who are affected by a standard oven even at low field strengths.
Elizabeth A Ainsbury et al, 2005 Phys. Med. Biol. 50 3197-3209
An investigation into the vector ellipticity of extremely low frequency magnetic fields from appliances in UK homes*
Elizabeth A Ainsbury, Emma Conein and Denis L Henshaw H H Wills Physics Laboratory, University of Bristol, Tyndall Avenue, Bristol BS8 1TL, UK
E-mail: Liz.Ainsbury@bristol.ac.uk
Received 21 February 2005, in final form 19 April 2005 Published 22 June 2005 Print publication: Issue 13 (7 July 2005)
Abstract: Elliptically polarized magnetic fields induce higher currents in the body compared with their plane polarized counterparts.
This investigation examines the degree of vector ellipticity of extremely low frequency magnetic fields (ELF-MFs) in the home, with regard to the adverse health effects reportedly associated with ELF-MFs, for instance childhood leukaemia.
Tri-axial measurements of the magnitude and phase of the 0–3000 Hz magnetic fields, produced by 226 domestic mains-fed appliances of 32 different types, were carried out in 16 homes in Worcestershire in the summer of 2004. Magnetic field strengths were low, with average (RMS) values of 0.03 ± 0.02 µT across all residences. In contrast, background field ellipticities were high, on average 47 ± 11%.
Microwave and electric ovens produced the highest ellipticities: mean respective values of 21 ± 21% and 21 ± 17% were observed 20 cm away from these appliances.
There was a negative correlation between field strength and field polarization, which we attribute to the higher relative field contribution close to each individual (single-phase) appliance. The measurements demonstrate that domestic magnetic fields are extremely complex and cannot simply be characterized by traditional measurements such as time-weighted average or peak exposure levels. We conclude that ellipticity should become a relevant metric for future epidemiological studies of health and ELF-MF exposure.
* This work is supported by the charity CHILDREN with LEUKAEMIA, registered charity number 298405.
doi:10.1088/0031-9155/50/13/016 URL: http://stacks.iop.org/0031-9155/50/3197 PII: S0031-9155(05)95015-X
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Abstract Submitted for the MAR05 Meeting of The American Physical Society Sorting Category: 10.13 (T)
Today's "safe" radiofrequency (RF) exposure limits DON'T protect human health near transmitters!
MARJORIE LUNDQUIST (1), The Bioelectromagnetic Hygiene Institute
Maxwell's theory implies that electromagnetic (EM) radiation carries both energy and momentum. The momentum may have both linear and angular contributions; angular momentum [AM] has a spin part associated with polarization and an orbital part associated with spatial distribution. Any interaction between radiation and matter is inevitably accompanied by an exchange of momentum. This often has mechanical consequences ..."(2)
Voluntary consensus standards [ANSI C95; NCRP; INCIRP] protect human health from most thermal [energy transfer] effects, but no standards yet exist to protect health against athermal [momentum transfer] effects, though laboratory transfer of spin AM was reported by 1935 (3) and of orbital AM by 1992 (2) for an optical vortex [tip of Poynting vector (PV) traces a helix about the beam axis].
In the far field of a dipole RF transmitter, radiation is linearly polarized (minimal spin AM) and locally approximated by a plane wave (zero orbital AM), but in the near field the orbital AM is non-zero [tip of PV traces an ellipse(4) in air] implying an athermal hazard [e.g., rain tumors in cellular phone users] against which no standard now in use anywhere in the world protects!
References: [1] P.O. Box 11831, Milwaukee WI 53211-0831 USA [2] L. Allen et al. Phys. Rev. A 45:8185-9 (1992). [3] R.A. Beth, Phys. Rev. 48:471(1935); 50:115-25 (1936). [4] F. Landstorfer, Archiv für Elektronik und Übertragungstechnik 26:189-96(1972) [in German].
Marjorie Lundquist
marlundquist@usa.net
The Bioelectromagnetic Hygiene Institute
----------------------------------------------
Abstract Submitted for the MAR05 Meeting of The American Physical Society Sorting Category: 18.3 (T)
A half-century ago physicists missed a major public service opportunity, costing the human race widespread chronic illness and many deaths!
MARJORIE LUNDQUIST, Bioelectromagnetic Hygiene Institute
Radar -- pulsed microwave (MW) radiation -- helped the Allies win World War II but health concerns soon arose. Alerted to a syndrome resembling mild radiation poisoning, (1) a worried M.D. surveyed radar-exposed workers, finding a high incidence of internal bleeding, (2) leukemia cases in 600 radar operators, 2 brain tumor cases in a 5-man MW research team and many complaints of headache. He sent his report (2) to the Pentagon in 1953.
Alarmed Navy officers convened a meeting (3) [mostly of electrical engineers (EEs)] to identify a safe level of MW exposure for servicemen. Biophysicist Herman Schwan attended, playing a major role in establishing 10 mW/cm2 as a thermally safe MW exposure limit. The IEEE became sole sponsor of ANSI C95 [an early health standard for radiofrequency (RF) exposure] with negative long-term consequences for human health!
I review RF health standards development since 1953, comparing what physicists might have done, had they -- not EEs -- had this responsibility! [See also my technical abstract.]
[1] N.H. Steneck, The Microwave Debate, Cambridge, MA: MIT Press, 1984; p. 33. [2] J.T. McLaughlin, A Study of Possible Health Hazards from Exposure to Microwave Radiation (Hughes Aircraft, Culver City CA, Feb. 9, 1953). [3] Biological Effects of Microwaves, meeting minutes (Navy Dept. Conference, Naval Medical Research Institute, Bethesda MD, Apr. 29, 1953).
Marjorie Lundquist
marlundquist@usa.net
Bioelectromagnetic Hygiene Institute
-Beau
ps. Note, it was found that ovens, both standard and microwave, generated fields with very high ellipticities compared to other appliances. This could explain those who are affected by a standard oven even at low field strengths.
Elizabeth A Ainsbury et al, 2005 Phys. Med. Biol. 50 3197-3209
An investigation into the vector ellipticity of extremely low frequency magnetic fields from appliances in UK homes*
Elizabeth A Ainsbury, Emma Conein and Denis L Henshaw H H Wills Physics Laboratory, University of Bristol, Tyndall Avenue, Bristol BS8 1TL, UK
E-mail: Liz.Ainsbury@bristol.ac.uk
Received 21 February 2005, in final form 19 April 2005 Published 22 June 2005 Print publication: Issue 13 (7 July 2005)
Abstract: Elliptically polarized magnetic fields induce higher currents in the body compared with their plane polarized counterparts.
This investigation examines the degree of vector ellipticity of extremely low frequency magnetic fields (ELF-MFs) in the home, with regard to the adverse health effects reportedly associated with ELF-MFs, for instance childhood leukaemia.
Tri-axial measurements of the magnitude and phase of the 0–3000 Hz magnetic fields, produced by 226 domestic mains-fed appliances of 32 different types, were carried out in 16 homes in Worcestershire in the summer of 2004. Magnetic field strengths were low, with average (RMS) values of 0.03 ± 0.02 µT across all residences. In contrast, background field ellipticities were high, on average 47 ± 11%.
Microwave and electric ovens produced the highest ellipticities: mean respective values of 21 ± 21% and 21 ± 17% were observed 20 cm away from these appliances.
There was a negative correlation between field strength and field polarization, which we attribute to the higher relative field contribution close to each individual (single-phase) appliance. The measurements demonstrate that domestic magnetic fields are extremely complex and cannot simply be characterized by traditional measurements such as time-weighted average or peak exposure levels. We conclude that ellipticity should become a relevant metric for future epidemiological studies of health and ELF-MF exposure.
* This work is supported by the charity CHILDREN with LEUKAEMIA, registered charity number 298405.
doi:10.1088/0031-9155/50/13/016 URL: http://stacks.iop.org/0031-9155/50/3197 PII: S0031-9155(05)95015-X
----------------------------------------------
Abstract Submitted for the MAR05 Meeting of The American Physical Society Sorting Category: 10.13 (T)
Today's "safe" radiofrequency (RF) exposure limits DON'T protect human health near transmitters!
MARJORIE LUNDQUIST (1), The Bioelectromagnetic Hygiene Institute
Maxwell's theory implies that electromagnetic (EM) radiation carries both energy and momentum. The momentum may have both linear and angular contributions; angular momentum [AM] has a spin part associated with polarization and an orbital part associated with spatial distribution. Any interaction between radiation and matter is inevitably accompanied by an exchange of momentum. This often has mechanical consequences ..."(2)
Voluntary consensus standards [ANSI C95; NCRP; INCIRP] protect human health from most thermal [energy transfer] effects, but no standards yet exist to protect health against athermal [momentum transfer] effects, though laboratory transfer of spin AM was reported by 1935 (3) and of orbital AM by 1992 (2) for an optical vortex [tip of Poynting vector (PV) traces a helix about the beam axis].
In the far field of a dipole RF transmitter, radiation is linearly polarized (minimal spin AM) and locally approximated by a plane wave (zero orbital AM), but in the near field the orbital AM is non-zero [tip of PV traces an ellipse(4) in air] implying an athermal hazard [e.g., rain tumors in cellular phone users] against which no standard now in use anywhere in the world protects!
References: [1] P.O. Box 11831, Milwaukee WI 53211-0831 USA [2] L. Allen et al. Phys. Rev. A 45:8185-9 (1992). [3] R.A. Beth, Phys. Rev. 48:471(1935); 50:115-25 (1936). [4] F. Landstorfer, Archiv für Elektronik und Übertragungstechnik 26:189-96(1972) [in German].
Marjorie Lundquist
marlundquist@usa.net
The Bioelectromagnetic Hygiene Institute
----------------------------------------------
Abstract Submitted for the MAR05 Meeting of The American Physical Society Sorting Category: 18.3 (T)
A half-century ago physicists missed a major public service opportunity, costing the human race widespread chronic illness and many deaths!
MARJORIE LUNDQUIST, Bioelectromagnetic Hygiene Institute
Radar -- pulsed microwave (MW) radiation -- helped the Allies win World War II but health concerns soon arose. Alerted to a syndrome resembling mild radiation poisoning, (1) a worried M.D. surveyed radar-exposed workers, finding a high incidence of internal bleeding, (2) leukemia cases in 600 radar operators, 2 brain tumor cases in a 5-man MW research team and many complaints of headache. He sent his report (2) to the Pentagon in 1953.
Alarmed Navy officers convened a meeting (3) [mostly of electrical engineers (EEs)] to identify a safe level of MW exposure for servicemen. Biophysicist Herman Schwan attended, playing a major role in establishing 10 mW/cm2 as a thermally safe MW exposure limit. The IEEE became sole sponsor of ANSI C95 [an early health standard for radiofrequency (RF) exposure] with negative long-term consequences for human health!
I review RF health standards development since 1953, comparing what physicists might have done, had they -- not EEs -- had this responsibility! [See also my technical abstract.]
[1] N.H. Steneck, The Microwave Debate, Cambridge, MA: MIT Press, 1984; p. 33. [2] J.T. McLaughlin, A Study of Possible Health Hazards from Exposure to Microwave Radiation (Hughes Aircraft, Culver City CA, Feb. 9, 1953). [3] Biological Effects of Microwaves, meeting minutes (Navy Dept. Conference, Naval Medical Research Institute, Bethesda MD, Apr. 29, 1953).
Marjorie Lundquist
marlundquist@usa.net
Bioelectromagnetic Hygiene Institute
Starmail - 23. Aug, 22:34
