Tuesday, November 11, 2008

Pylons 'double risk of dying from dementia'

Pylons 'double risk of dying from dementia'

By Nick Fagge


LIVING close to pylons and high-voltage cables doubles the risk of dying from Alzheimer's disease and senile dementia, a study claims.

Researchers say they have found a direct link between the electromagnetic fields created by power lines and all types of dementia.

The study by doctors at Bern University's Institute of Social and Preventative Medicine in Switzerland is the latest evidence pointing to the dangers posed by power lines.

An estimated 150,000 Britons live within the 165ft danger zone of electricity pylons, according to Professor Denis Henshaw, an expert on human radiation.

And last night the University of Bristol scientist said: "It is now time that electricity pylons are pulled down and power cables are buried in highly populated areas of the country." However, National Grid, which manages the network, said putting highvoltage cables underground posed different risks and was prohibitively expensive.

It said: "Underground cabling for high-voltage lines can cost between six and 17 times as much as using overhead lines.

"Underground cables can also pose more of a risk because of the danger of them being hit by excavation, and they are more difficult to maintain."

The UK has at least 14,000 miles of high-voltage cable carrying electricity from power stations to homes and businesses.

The Swiss team, led by Professor Matthias Egger, found the risk of developing Alzheimer's increases the longer people live next to electricity pylons.

He said yesterday: "Anyone who lives within the immediate vicinity of high-voltage power lines for more than 10 years has a significantly higher risk of developing dementia or Alzheimer's."

The paper has been published in the American Journal of Epidemiology.

Professor Henshaw claims that radiation caused by power lines and other high-power electrical sources stops the body creating the natural hormone melatonin in the pineal gland, which is lacking in Alzheimer's sufferers.

He said: "This paper is like the final piece of a jigsaw. The link between childhood leukaemia and power lines is already accepted by everybody. And there is strong evidence of a link to other diseases as well."

Professor Egger warns that sleeping next to a radio-operated alarm clock or living beside an electrified railway line present a similar dementia risk, due to proximity of the radiation source and the strength of the electric charge. He said: "Anything that is plugged in and that is on all the time and that is near to your body is a source of this type of radiation."

National Grid said last night: "We recognise that there is some scientific evidence suggesting certain specific health effects may be linked to electric and magnetic fields. This can cause public concern.

"However, the balance of evidence remains against electric and magnetic fields causing ill health."

Last night the Department of Health said it was reviewing its position in the light of the study.


American Journal of Epidemiology Advance Access published online on November 5, 2008

American Journal of Epidemiology, doi:10.1093/aje/kwn297

Residence Near Power Lines and Mortality From Neurodegenerative Diseases: Longitudinal Study of the Swiss Population

Anke Huss, Adrian Spoerri, Matthias Egger, Martin Röösli and for the Swiss National Cohort Study

Correspondence to Dr. Anke Huss, Institute of Social and Preventive Medicine, University of Bern, Finkenhubelweg 11, CH-3012 Bern, Switzerland (e-mail: ahuss@ispm.unibe.ch ).

Received for publication May 5, 2008. Accepted for publication August 25, 2008.

The relation between residential magnetic field exposure from power lines and mortality from neurodegenerative conditions was analyzed among 4.7 million persons of the Swiss National Cohort (linking mortality and census data), covering the period 2000–2005. Cox proportional hazard models were used to analyze the relation of living in the proximity of 220–380 kV power lines and the risk of death from neurodegenerative diseases, with adjustment for a range of potential confounders. Overall, the adjusted hazard ratio for Alzheimer's disease in persons living within 50 m of a 220–380 kV power line was 1.24 (95% confidence interval (CI): 0.80, 1.92) compared with persons who lived at a distance of 600 m or more. There was a dose-response relation with respect to years of residence in the immediate vicinity of power lines and Alzheimer's disease: Persons living at least 5 years within 50 m had an adjusted hazard ratio of 1.51 (95% CI: 0.91, 2.51), increasing to 1.78 (95% CI: 1.07, 2.96) with at least 10 years and to 2.00 (95% CI: 1.21, 3.33) with at least 15 years. The pattern was similar for senile dementia. There was little evidence for an increased risk of amyotrophic lateral sclerosis, Parkinson's disease, or multiple sclerosis.

dementia; neurodegenerative diseases; radiation, nonionizing

Abbreviations: ALS, amyotrophic lateral sclerosis; CI, confidence interval; ELF-MF, extremely low frequency magnetic field(s); ICD-10, International Classification of Diseases, Injuries, and Causes of Death, Tenth Revision