The Icelandic volcanic eruption that has paralysed air traffic in the UK and much of Europe could also harm people with breathing problems, according to the World Health Organization (WHO).
The United Nations health agency has not yet ascertained the heath risks from this specific eruption, but once the clouds settle they could be dangerous, said WHO spokesman Daniel Epstein.
“Any particulate matter that is deposited, breathed into the lungs is dangerous to people so we are concerned about that but we don't have details yet,” he told a briefing.
WHO drew up health guidelines in 2005 on particles emitted from eruptions, said Mr Epstein, who added: “This is very dangerous to health because these particles when inhaled can reach the peripheral regions of the bronchioles and lungs and can cause problems especially for people with asthma or respiratory problems.”
A Scottish expert on respiratory disease, however, said ash falling on the UK was unlikely to do much harm, as a very high exposure to the low-toxicity dust was needed to have much effect on people.
“There is a massive diluting effect in the atmosphere as it gets dispersed by wind which means the amount reaching land is very small,” said Ken Donaldson, professor of respiratory toxicology at the University of Edinburgh.
Mr Epstein said he understood the cloud from the volcano was still suspended high in the atmosphere and particles had not begun to settle on earth.
Once that happened the health risk would increase and people with asthma or other respiratory problems should stay indoors or wear protective masks if they had to go out, as in any other case of airborne pollution, he said.
Professor Donaldson agreed that people with existing lung disease should stay indoors if there was a measurable change in particle levels.
The eruption that began on Wednesday of last week from a volcano under an Icelandic glacier has created chaos in European air travel.
The Health Protection Agency said that because small quantities of volcanic ash could float back up into the air in windy conditions it would be sensible for people with existing respiratory conditions such as chronic bronchitis, emphysema and asthma to ensure they kept their inhalers or other medications with them.
In addition, the HPA advised if people were outside and noticed symptoms such as itchy or irritated eyes, runny nose, sore throat or dry cough, or if they noticed a dusty haze in the air or could smell sulphur, rotten eggs, or a strong acidic smell, they might wish to limit their activities outdoors or return indoors.
Any such health effects were likely to be short term, said the agency, which is continuing to monitor the situation with the Health Protection Scotland, Public Health Wales and the Met Office.
Source: Reuters Health