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The radon effect in electromagnetic fields

The radon effect in electromagnetic fields  M J O'Carroll, April 1997

On 14 February 1996 Henshaw announced [1] experimental results showing enhanced deposition of harmful radon products upon surfaces in the presence of power frequency electromagnetic fields (EMFs).

The NRPB issued a press release [2] embargoed for the same day reacting to Henshaw's announcement, asserting "The consequence of increased plateout is that fewer radon daughters will remain in the air to be breathed in by the occupants and so exposure by inhalation is lowered" and "the weight of evidence would suggest the presence of electric fields will, if anything, slightly reduce human exposure to radon daughters". No evidence is cited relating to radon other than Henshaw's paper.

NRPB's assertion depends on the assumption that a change in human exposure to radon products would be governed principally by a change in their concentration in the air, and that this will be diminished by enhanced surface deposition (or plateout). This ignores the oscillation effect of EMFs which would increase deposition with the same concentration. Concentration in the air will depend on diffusion, convection, radiation, birth, decay and surface deposition and emission. NRPB's assumption is unsound. Indeed the one thing which is demonstrated by the experiments is enhanced deposition (up to a factor of 18), so that human exposure by deposition (on the skin) will be increased whether or not concentration is decreased.

Henshaw's paper identifies three potential mechanisms for the effect: polarisation drift, oscillation in an alternating field and enhanced diffusivity along field lines. The first and third mechanisms affect concentration, but the second only affects interaction with surfaces. The paper dismisses polarisation drift as too small and says there is insufficient information to assess enhanced diffusivity. Some experimental results show very sharp gradients of deposition, particularly near to electrodes or conductors. These results are from exposures over 6 days, but are not characterisitic of long term concentration gradients when diffusion is significant.

In the simulation of fields under powerlines, with 10 day exposures, increased deposition is smoother and spread over a length scale of a metre. Henshaw identifies deposition due to "airborne activity", i.e. from emissions from airborne particles, separately from direct collisions, and takes this as an indicator of the local concentration of such particles. It is however not conclusive that increased deposition is due to increased concentration rather than to oscillation.

[1] D L Henshaw et al, Enhanced deposition of radon daughter nuclei in the vicinity of power frequency electromagnetic fields, Int J Radiation Biol 69(1), 25-38, 1996.

[2] NRPB, Radon and electromagnetic fields seen as separate health issues,  12.2.96.

See also:
City of Lincoln Local Plan Public Inquiry  Proof of Evidence of M J O'Carroll  14 April 1997

Public health concern about electromagnetic fields from electricity supply.

Prudent avoidance 

Abstract of Enhanced Deposition of Radon Daughter Nuclei in the Vicinity of Power Frequency Electromagnetic Fields

Further comment on the above
"The above research findings went through the normal academic assessment procedure before they were accepted for publication by the International Journal of Radiation Biology. We were asked to respond to a number of specific points which, in view of the wider public interest, we are reproducing below"


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