Electric fields and ions – NRPB comments

On 1 April 2005, the NRPB joined the Health Protection Agency, becoming the Radiation Protection Division.  In 2013, HPA became part of Public Health England.

We include here all the public comments made by the NRPB, but the earliest comments are now some time ago and aspects of science may have moved on since then.

 

Comments on 1996 paper

In response to the 1996 paper by Henshaw et al, the NRPB made the following comments:

“The authors of the paper go on to speculate that there may be some mechanism by which electric fields cause radiation doses from the inhalation of radon daughters to be increased, but offer no credible explanation why this should occur. The theory is implausible: the weight of evidence would suggest the presence of electric fields will, if anything, slightly reduce human exposures to radon daughters.”

“No biological mechanism has been established to indicate that electromagnetic fields can influence any of the accepted stages in the development of cancer.

The paper from Bristol University, which is purely speculative on the issue of radon and EMFs, does not change the Board’s view.”

 

Comments on 1999 papers

Commenting on the 1999 papers by Fews et al, the NRPB said:

“The publication of these latest papers from the Bristol scientists has not changed the NRPB view that there is no convincing evidence that the observed physical phenomenon can have any effect on childhood cancer.”

 

2001 AGNIR Report

The NRPB’s Advisory Group Report of 2001 contained the following statement (p23):

“The physical principles for enhanced aerosol deposition in large electric fields are well understood. However, it has not been demonstrated that any such enhanced deposition will increase human exposure in a way that will result in adverse health effects to the general public.”

 

2003 AGIR Report 

Report by the NRPB's Advisory Group on Ionising Radiation, dealing with the risk of leukaemia following radiation exposure, considered the 1996 suggestion of Henshaw et al that the deposition of radon daughter nuclei is enhanced in the vicinity of power frequency electromagnetic fields. It concluded:

"To conclude, the hypotheses put forward by Henshaw et al (1996) do not indicate that doses to the bone marrow would be increased as a consequence of enhanced deposition of radon decay products in the vicinity of power frequency electromagnetic fields. Furthermore, epidemiological studies have not tended to find raised childhood leukaemia risks with increased levels of radon in homes or with greater proximity to power lines. Consequently, associations such as that reported in the pooled analysis of Ahlbom et al (2000) - between childhood leukaemia and high magnetic field levels - are unlikely to be due to increased radon exposure."

 

2004 AGNIR Report

The NRPB’s Advisory Group on Non-Ionising Radiation set up an ad-hoc group to consider these mechanisms. AGNIR itself then considered the possible health consequences and published a report.

On the suggestion that corona ions transfer charge to airborne pollutants and thereby increases the probability of deposition in the airways and lungs, the report concludes that corona ions are produced by some power lines; that they do transfer some charge to airborne pollutants; that charge can increase deposition in airways; and that airborne pollutants can be harmful to health. The report concludes “There are substantial difficulties in the way of modelling such effects, making all such estimates very uncertain”, but on the basis of available calculations concludes:

“…it seems unlikely that corona ions would have more than a small effect on the long-term health risks associated with particulate air pollutants, even in the individuals who are most affected. In public health terms, the proportionate impact will be even lower because only a small fraction of the general population live or work close to sources of corona ions.”

On the suggestion that electric fields under power lines can increase deposition of particles on the skin, the report concludes that this does happen, albeit only out of doors; that “the physical situation is very complicated and it seems unlikely that it can be modelled with sufficient accuracy to provide reliable information in the foreseeable future”; but that

“Any health risks from the deposition of environmental particulate air pollutants on the skin appear to be negligible.”

 

International Agency for Research on Cancer

Both the 1996 and the 1999 papers were considered by the IARC Working Group which decided the evidence that electric fields cause cancer was “inadequate” for both humans and animals, and that as a consequence electric fields were “not classifiable” with respect to carcinogenicity.