HERE is what the Health Protection Agency has to say on electro-sensitivity.

THE Health Protection Agency's Radiation Protection Division has published a review of electrical sensitivity.

This is a condition which some people attribute to exposure to electromagnetic fields associated with the electricity supply and electrical equipment.

However, the use of the term electrical sensitivity in the review does not imply acceptance of a causal relationship between symptoms and attributed exposure.

The review of the phenomenon is from a public health viewpoint looking at how the condition can be defined, its prevalence, possible options for managing it and any similarities with other conditions.

People complaining of the condition can have real, unpleasant and sometimes disabling symptoms.

The review has included papers from the peer reviewed scientific literature but it has also considered other sources of information, such as internet websites maintained by sufferers and self-help groups.

In the peer reviewed scientific literature electrical sensitivity and its synonyms largely refer to symptoms attributed to exposure to power frequency electromagnetic fields.

Hence the conclusions of the review are applicable primarily to these fields rather than those from radiofrequency transmissions.

Two main groups of symptoms are attributed to electrical sensitivity (also known as electrical hypersensitivity).

Firstly, skin symptoms, especially facial symptoms, often associated with using older types of visual display unit.

Secondly, a wider range of more generalised symptoms, especially fatigue and headaches, which vary from person to person.

These symptoms have been reported in a number of different countries where studies have been undertaken. The symptoms can be mild but in some people they are severe enough to be disabling and hinder normal life.

Such severe symptoms only occur in about 10 per cent of sufferers. Although the symptoms are attributed to exposure to various types of electromagnetic fields, the review notes there is no proven scientific link between such exposures and symptoms.

A number of studies have looked at diagnostic markers for electrical sensitivity but no consistent marker has been found.

The published literature does not suggest that sufferers have a particular set of personal characteristics.

The prevalence of electrical sensitivity has not been measured in the UK.

Using estimates from elsewhere, together with information from self-help groups, the prevalence in countries where it has been measured is estimated to be between a few per thousand and a few per million of the population.

Most of the peer-reviewed scientific reports of electrical sensitivity, especially those published before the widespread adoption of mobile telephony, describe studies of reactions to electrical equipment and appliances.

It is not always easy to define what the attributed triggers were in every study.

More recently, similar symptoms have been reported from exposure to radio frequency transmissions and there is some research being carried out in the UK on this topic.

The review found that people who attribute illness to chemical and other environmental exposures report similar symptoms to electrical sensitivity.

There are also reports that symptoms can initially be precipitated by one sort of exposure and then bring on symptoms from other types of exposure. However, scientific studies of this phenomenon are few.