Overhead power lines a complex public health hazard more than just EMF by Dr Chris Barnes, Bangor Scientific and Educational Consultants August 2013 e-mail firstname.lastname@example.org
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A review of the literature shows EMF to be associated with childhood leukaemia. There is dispute regarding mechanisms and whether magnetic or electric components of EMF are to blame. Government health advice focuses mainly on residential magnetic fields. The contribution of magnetic fields is not disputed here but an extra, possibly more relevant facet the potency of the electric field component of power lines to concentrate atmospheric carcinogens is explored and would appear to be vindicated. A case for undergrounding follows. Suggests for further work are raised.
In recent years questions have been raised concerning the safety of electromagnetic fields. These have come to the fore due to health concerns over mobile phone use. Although mobile phones operate at radio frequencies some 8 orders of magnitude higher than those emitted by power lines they are often lumped by both public bodies of concern, epidemiologists and even government advisory committees under the same general banner of EMF (electromagnetic fields) or EMR (electromagnetic radiation).
It is notoriously difficult to perform epidemiological studies on the health effects of electromagnetic fields because they are ubiquitous in our society and people are exposed to multiple sources and multiple frequencies in their daily lives.
EMFS have been associated with various disease states and the easiest studies to do have been those associated with occupational exposure. Even though far more people are cured these days the most emotive disease state remains cancer. Careful literature searches and the work of Ahlbom et al (2001) reveal that the only cancer positively associated with EMF beyond any doubt is leukaemia and especially childhood leukaemia.
Leukaemia clusters appear to have been associated with EMF at all kinds of frequencies from 50 Hz to those modulated emissions of radio and TV masts.
Leukaemia seems especially to have been associated with the electric/or magnetic fields of power lines and of residential exposure. Regarding weak to moderate magnetic fields of environmental magnitudes a truly fascinating piece of work and new hypothesis has recently come to light, see Li and Heroux (2012). They show that over a relatively wide range of fields and for a flat dose response many types of cancer cell lines actually show karyotype contractions and it is only erythro- leukaemia cells which show a progressive rise in the specific range .025 to .4 microT. This is exactly the magnetic field range given off by typical household wiring. The present author has recently shown that when occupational adjustment is made, all cancer rates including Leukaemia are significantly lower in the Ohio Amish, a religious community of some 9,000 inhabitants who are employed almost exclusively in farming and furniture making and who do not use mains electricity, see Some brief comments on the Amish and Cancer ( Barnes 2013).
Potent power lines
The purpose of this short paper, however, is to briefly review the relevant literature in order to enquire if all EMFS are the same or if there is something different about power lines, particularly overhead power lines that makes them even more potent than household wiring with regard to leukaemia. The work of Lennart Tomenius M.D (2005) for all kinds of tumours is interesting. It seems to suggest that the presence of overhead 200 kV conductors is more relevant than high residential magnetic fields especially for leukaemia but less so for nervous system tumours. In other words the present author feels perhaps somehow electric field due to overhead lines is more potent in producing leukaemia whereas magnetic fields are more potent at producing nervous system tumours.
Another study of 31,453 Ontario electric utility workers by Villeneuve et al (2000) showed that the percentage of time spent above electric field thresholds of 20 and 39 V/m was predictive of leukemia risk after adjusting for duration of employment and the arithmetic mean exposure to both electric and magnetic fields (P < 0.05). Duration of employment was strongly associated with an increased risk of leukemia. Those who had worked for at least 20 years, and were in the highest tertiles of percentage of time spent above 10 and 20 V/m had odds ratios of 10.17 (95% CI = 1.58–65.30) and 8.23 (95% CI = 1.24–54.43), respectively, when compared to those in the lowest tertile. Nonsignificant elevations in risk were observed between indices of magnetic fields and leukemia. It concluded that the results supported the hypothesis that electric fields act as a promoting agent in the etiology of adult leukemia.
So here we have two studies which specifically suggest that the electric field of power lines is more potent at producing leukaemia.
Fews et al (1999) showed that power lines concentrate atmospheric pollutant aerosols even radioactive isotopes. Vera (2006) found that power lines concentrate Chloride ions which accelerate conductor corrosion.
Henshaw (1996) showed that power lines concentrate radon, a known carcinogen. Evrard ET AL (2006) have showed moderate ecological association between childhood AML incidence and indoor radon does not appear to be confounded by terrestrial gamma dose. There are however other studies which show no such association whatsoever. Raaschou-Nielsen et al show that domestic radon exposure increases the risk for ALL during childhood but not for other childhood cancers.
Scientists at Kalmar University nbcnews.com/id/34370106/ns/health-health_care/t/power-line-pollutants-pose-health-risks/ have recently shown that power lines concentrate carcinogens such as PCBS. On the other hand their efforts to sicken laboratory animals using electric and magnetic fields have shown little or no effect. It is believed that a similar concentration would take place for Dioxins or PAHS. PCBS are known to cause leukaemia in marine invertebrates see Harper et al (1994). Ward et al (2009) showed for the first time ever that PCBS are a significant risk for childhood leukaemia with an odds ratio of approximately 2. Coincidentally, this is the same odds ratio often found and blamed in association with the EMF of power lines. Bernbaun and Fenton (2003) have suggested prenatal exposure to endocrine disruptors like dioxins could cause childhood tumours and leukaemia. Reynolds et al (2003) have findings which suggest an association between increased childhood leukemia rates and high hazardous air pollution exposure, but more studies involving more comprehensive exposure assessment and individual-level exposure data will be needed for elucidating this relationship. Belson (2007) finds in general, benzene and ionizing radiation are two environmental exposures strongly associated with the development of childhood AML or ALL. Hsu-Huei Weng et al (2008) have showed a strong association between exposure to traffic exhaust pollutants and childhood leukemia. The present author feels there is no reason why these pollutants could not be concentrated by the strong electric field of high voltage power lines.
The association of childhood leukaemia with electrification of rural areas has been further commented on by Milham and Ossiander (2001) who have shown that the condition began to peak in the UK in the 1920's but its emergence lagged behind in time in the USA where 75% of rural areas were not electrified until 1956. Early electrification always used high voltage overhead pylons.
The above is not meant to suggest that magnetic fields are not dangerous per se but merely that the associative factor of high voltage electricity and its attendant fields with pollutant particles and aerosols might be even more relevant when it comes to risk.
One very interesting piece of work which highlights the above findings elegantly is that of Hintenlang Bioelectromagnetics Volume 14, Issue 6, 545–551, 1993 who designed experiments to evaluate the synergistic production of clastogenic effects by ionizing radiation and 60 Hz magnetic fields were performed using human lymphocytes from peripheral blood. Following exposure to ionizing radiation, cells were cultured in 60 Hz magnetic fields having field strengths up to 1.4 mT. Cells exposed to both ionizing radiation and 60 Hz magnetic fields demonstrated an enhanced frequency of near tetraploid chromosome complements, a feature not observed following exposure to only ionizing radiation. The results are discussed in the context of a multiple-stage model of cellular transformation, employing both initiating and promoting agents. At first site it may be tempting to suggest on the basis of this study that magnetic field is all important. With a little imagination and lateral thinking, however, it remains easy to comprehend that where there is high voltage electricity there will be both magnetic fields and ionising radiation from concentration for example of atmospheric aerosols and natural radon gas by nothing other than strong electric fields.
The Science discussed above suggests that overhead power lines are a complex health hazard wherein risk of electric and magnetic fields could by compounded by their ability to concentrate all kinds of atmospheric pollutants and radioactive isotopes. This is more strongly a function of electric field at ground level or voltage on the line rather than magnetic field. An archived government Public Health document suggests there is no problem with electric fields and that we should focus on magnetic fields. http://webarchive.nationalarchives.gov.uk/+/www.dh.gov.uk/en/Publichealth/Healthprotection/DH_4089500. When reading that document it is clear that one of the scientific advisors to that body effectively comments that the whole process has been little more than a sham and that those involved have not understood the science behind the processes involved.
Case for undergrounding
The work presented above is the general foundation for a case for the undergrounding of high voltage electricity distribution cables even as low as 11kV based on the threshold fields in one study above.
Further work needs to be done on the influence of weather and location on the concentration of radon and atmospheric pollutants by electricity distribution systems.
In Britain the prevailing winds are South Westerly. Studies should be made to see if there is more leukaemia clusters to the North East of power lines as well as in their immediate vicinity. Increased risk is to be expected in residential areas which are both adjacent to roads or motorways and power lines or adjacent to power-lines and under major air traffic routes. These factors too could be tested for.