Two official Department of Health reports on the smog are to be presented to ministers next month, and the Health Protection Agency (HPA) has recently held the first meeting of an expert group charged with developing advice to the public on the threat.

The UN's World Health Organisation (WHO) calls the electronic smog "one of the most common and fastest growing environmental influences" and stresses that it "takes seriously" concerns about the health effects. It adds that "everyone in the world" is exposed to it and that "levels will continue to increase as technology advances".

Wiring creates electrical fields, one component of the smog, even when nothing is turned on. And all electrical equipment - from TVs to toasters - give off another one, magnetic fields. The fields rapidly decrease with distance but appliances such as hair dryers and electric shavers, used close to the head, can give high exposures. Electric blankets and clock radios near to beds produce even higher doses because people are exposed to them for many hours while sleeping.

Radio frequency fields - yet another component - are emitted by microwave ovens, TV and radio transmitters, mobile phone masts and phones themselves, also used close to the head.

The WHO says that the smog could interfere with the tiny natural electrical currents that help to drive the human body. Nerves relay signals by transmitting electric impulses, for example, while the use of electrocardiograms testify to the electrical activity of the heart.

Campaigners have long been worried about exposure to fields from lines carried by electric pylons but, until recently, their concerns were dismissed, even ridiculed, by the authorities.

But last year a study by the official National Radiological Protection Board concluded that children living close to the lines are more likely to get leukaemia, and ministers are considering whether to stop any more homes being built near them. The discovery is causing a large-scale reappraisal of the hazards of the smog.

The International Agency for Research on Cancer - part of the WHO and the leading international organisation on the disease - classes the smog as a "possible human carcinogen". And Professor David Carpenter, dean of the School of Public Health at the State University of New York, told The Independent on Sunday last week that it was likely to cause up to 30 per cent of all childhood cancers. A report by the California Health Department concludes that it is also likely to cause adult leukaemia, brain cancers and possibly breast cancer and could be responsible for a 10th of all miscarriages.

Professor Denis Henshaw, professor of human radiation effects at Bristol University, says that "a huge and substantive body of evidence indicates a range of adverse health effects". He estimates that the smog causes some 9,000 cases of depression.

Perhaps strangest of all, there is increasing evidence that the smog causes some people to become allergic to electricity, leading to nausea, pain, dizziness, depression and difficulties in sleeping and concentrating when they use electrical appliances or go near mobile phone masts. Some are so badly affected that they have to change their lifestyles.

While not yet certain how it is caused, both the WHO and the HPA accept that the condition exists, and the UN body estimates that up to three in every 100 people are affected by it.

Case History: 'I felt I was going into meltdown'

Until a year ago, Sarah Dacre reckoned she had a "blessed life". Running her own company, and living in an expensive north London home, the high-earning divorcee described herself as "fab, fit and 40s". Then suddenly the sight in her right eye failed: she first noticed it when she was unable to read an A-Z map. Soon she was getting pains and numbness in her joints. She could not sleep and spent nights "pacing about like a caged lion". Her short-term memory failed and if she took notes to remind her, she would forget she had made them.

The symptoms got worse whenever she was exposed to electricity. She could not use a computer for more than five minutes without becoming nauseous. Even using a telephone landline gave her a buzzing in the ear and made her feel she was "going into meltdown".

The Carnegie Institution of Washington study is reported in Science magazine.

It challenges the notion that the only way we can investigate our molecular origins is to try to collect samples of unaltered cosmic material from space - the driving force behind missions such as Stardust.

Instead, the Carnegie team argues that primitive organic materials - essentially unaltered components of the original building blocks of the Solar System - can be found in the pieces of interplanetary rock and metal that land on our planet.

Organic 'fingerprints'

The US scientists analysed six carbonaceous chondrite meteorites - the oldest type known.

Elephant Moraine meteorite (Science Photo Library)
It was thought meteorites would contain only altered material
Using new techniques, the researchers looked at the relative proportions of different types (isotopes) of nitrogen and hydrogen atoms associated with the meteorites' organic matter.

Their analysis found regions where there was an excess of the heavier forms of these elements - something also found in interstellar dust grains.

It suggested, therefore, that the meteorites contained material that had been largely unaltered since the time when the Solar System was formed from the collapse of a giant cloud of gas and dust called the solar nebula.

"It's amazing that pristine organic molecules associated with these isotopes were able to survive the harsh and tumultuous conditions present in the inner Solar System when the meteorites that contain them came together," said Carnegie researcher Conel Alexander.

"It means that the parent bodies - the comets and asteroids - of these seemingly different types of extraterrestrial material are more similar in origin than previously believed."

Elusive time period

The discovery opens up a new window to study a long-gone era.


"Before, we could only explore minute samples from interplanetary dust particles (IDPs)," said the lead author of the Science paper, Henner Busemann.

"Our discovery now allows us to extract large amounts of this material from meteorites, which are large and contain several percent of carbon, instead of from IDPs, which are on the order of a million, million times less massive."

The scientists believe that further investigation of meteorites may yield enough material to perform experiments that would not be possible with the tiny primitive organic grains from interplanetary dust particles or cometary grains returned by the US space agency's (Nasa) Stardust mission.

Pre-solar origin

UK planetary expert Ian Wright, of the Open University in Milton Keynes, believes we now have the potential to be able to study pre-solar organic molecules in the laboratory.

"That organic molecules in carbonaceous chondrites are, at least in part, pre-solar in origin, is not a new idea," he told the BBC News website.

"What is presented here are data that show that the distribution of isotopic compositions within the organic complex is [highly varied].

"I guess it is possible that we could be looking at the remnants of precursor organic molecules, formed in the interstellar medium before the Solar System even existed, embedded in a complex that formed at a later time (perhaps within the solar nebula itself)."

And thanks to satellite positioning systems, they can now be programmed to hit targets some distance away with just a few metres (yards) short of pinpoint accuracy.

Security services the world over have been considering the problem for several years, but no one has yet come up with a solution.

"We are observing an increasing threat from such things as remote-controlled aircraft used as small flying bombs against soft targets," the head of the Canadian secret services, Michel Gauthier, said at a conference in Calgary recently.

According to Gauthier, "ultra-light aircraft, powered hang gliders or powered paragliders have also been purchased by terrorist groups to circumvent ground-based countermeasures."

On May 1 the US website Defensetech published an article by military technology specialist David Hambling, entitled "Terrorists' unmanned air force".

"While billions have been spent on ballistic missile defense, little attention has been given to the more imminent threat posed by unmanned air vehicles in the hands of terrorists or rogue states," writes Hambling.

Armed militant groups have already tried to use unmanned aircraft, according to a number of studies by institutions including the Center for Nonproliferation studies in Monterey, California, and the Center for Arms Control, Energy and Environmental Studies in Moscow.

In August 2002, for example, the Colombian military reported finding nine small remote-controlled planes at a base it had taken from the Revolutionary Armed Forces of Colombia (FARC).

On April 11, 2005 the Lebanese Shiite militia group, Hezbollah, flew a pilotless drone over Israeli territory, on what it called a "surveillance" mission. The Israeli military confirmed this and responded by flying warplanes over southern Lebanon.

Remote-control planes are not hard to get hold of, according to Jean-Christian Delessert, who runs a specialist model airplane shop near Geneva.

"Putting together a large-scale model is not difficult -- all you need is a few materials and a decent electronics technician," says Delessert.

In his view, "if terrorists get hold of that, it will be impossible to do anything about it. We did some tests with a friend who works at a military radar base: they never detected us... if the radar picks anything up, it thinks it is a flock of birds and automatically wipes it."

Japanese company Yamaha, meanwhile, has produced 95-kilogram (209-pound) robot helicopter that is 3.6 metres (11.8 feet) long and has a 256 cc engine.

It flies close to the ground at about 20 kilometres per hour (12 miles per hour), nothing but an incredible stroke of luck could stop it if it suddenly appeared in the sky above the White House -- and it is already on the market.

Bruce Simpson, an engineer from New Zealand, managed to produce an even more dangerous contraption in his own garage: a mini-cruise missile. He made it out of readily available materials at a cost of less than 5,000 dollars (4,000 euros).

According to Simpson's website, the New Zealand authorities forced him to shut down the project -- though only once he had already finished making the missile -- under pressure from the United States.

Eugene Miasnikov of the Center for Arms Control, Energy and Environmental Studies in Moscow said these kinds of threats must be taken more seriously.

"To many people UAVs (unmanned aerial vehicles) may seem too exotic, demanding substantial efforts and cost compared with the methods terrorists frequently use," he said. "But science and technology is developing so fast that we often fail to recognise how much the world has changed."