The radioactive traces found on two British Airways planes have alarmed the 33,000 passengers who took one of the 221 flights that could have been affected. Over 2,500 of them have been calling the airline's helpline to find out more about their potential exposure.
But experts say most planes contain harmless amounts of radiation. And even if passengers were exposed to polonium-210, the radioactive substance found in the body of ex-KGB agent Alexander Litvinenko, there is very little risk of harm.
"Even if I had been on the same plane as the spy or whoever was carrying [the polonium-210], I wouldn't have any concerns that I would have been exposed," says Kelly L. Classic, a spokesperson for the Health Physics Society (HPS), which is composed of specialists in radiation safety. "In any case, as soon as I wash my hands, it would wash off."
Polonium exists naturally in very low concentrations in our bodies and in the soil and air. Classic explains that it is a health hazard only if it's taken into the body through eating, drinking or breathing and only if the amount is more than one or two micrograms. Still, less than one gram of the silver powder is enough to kill you.
When ingested in larger amounts, traces of polonium will enter the bloostream and affect many tissues and organs, especially the spleen, kidneys, liver and bone marrow. Symptoms are similar to food poisoning -- nausea, diarrhea, vomiting and tiredness. Higher doses cause hair loss, depletion of white blood cells and death.
The substance can also be found in industrial static eliminators (not the more common household sprays like Static Guard or cloths) and brushes that remove dust from camera lenses and film. It is also found in trace amounts in cigarettes and is one of the causes of lung cancer in smokers.
But most hand-held radiation detectors would not pick up traces of polonium. The British authorities would have to use alpha probes, which detect alpha particles that are emitted by radioactive elements, to detect polonium, according to a fact sheet issued by the HPS.
British authorities wouldn't say whether the radioactive substance found on the two planes was polonium, explaining that it remained unidentified. They are focusing on four flights made by its planes between Heathrow Airport and Moscow between Oct. 25 and Nov. 3.
As for radiation in general, there are trace amounts on most airplanes in use. Everything from smoke detectors, treatments given to cancer patients, and appliance indicator lights contain small amounts of radiation.
In addition, frequent travelers are exposed to cosmic radiation, which is, essentially, harmless microwave background radiation. According to one test conducted in 2000, the highest rates were discovered on a Paris-to-Tokyo flight and the lowest rates on a Paris-to-Buenos Aires flight. That difference is largely due to the fact that radiation particles are deflected by the Earth's magnetic field, and that effect is most pronounced near the equator.
So far, most travelers don't seem too concerned. "We haven't received any calls from people who are concerned about flying to Russia," says Marina, a travel agent at Russian Travel, an agency in Brighton, England, that specializes in travel to Russia. "Everything is normal -- if anything, it's picking up as people book their Christmas vacations."