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Article courtesy of The Sydney Morning Herald | April 18, 2010 | Shared as educational material
HEALTH authorities have warned that the fallout of volcanic ash over parts of Iceland could jeopardise the safety of its drinking water.
And a geophysicist said the eruption showed no signs of abating.
Halldor Runolfsson from the Icelandic Food and Veterinary Authority said there were concerns for human health but the greatest risk was to livestock.
”It is important to prevent the ash from reaching water supplies, both for public and animal health reasons and for safe milk production.”
His colleague Guthjon Gunnarsson said the agency was evaluating the quality of drinking water, which was mostly protected because it was sourced from under the ground.
Dr Runolfsson said the ash posed the greatest risk to livestock because it contained high levels of fluoride, which can cause problems in bones and teeth.
Since the eruption began on Wednesday, it has been spewing a six-kilometre plume of ash into the sky, sending a giant cloud of it towards Europe and prompting the continent’s biggest air travel shutdown since World War II.
The question for scientists is how long the eruption might continue, particularly at its current strength. Geophysicist Pall Einarsson, from the Institute of Earth Sciences at the University of Iceland, said that question could not yet be answered.
Iceland had many volcanoes, and their eruptions often followed a pattern, Professor Einarsson said. ”Usually they are most vigorous in the beginning. But this volcano is very different from that.”
Researchers were monitoring the volcano for indications that the eruption was tapering off.
One complication was the eruption’s location, under the Eyjafjallajokull glacier. The underside of the ice has melted, causing flooding, forcing evacuations and destroying bridges and roads. The rest of Europe is concerned about how the meltwater might affect the volcano and the ash it generates.
Jennie Gilbert, from the University of Lancaster in Britain, said the presence of water could affect the characteristics of the sandlike ash produced by the volcano. As the molten rock hits the cold water, it is fused into a glassy material. When the pressure builds up and the volcano explodes, this material breaks up into fine particles. In Britain, the Health Protection Agency said some particles might settle to the ground but may not be visible.
It advised people – particularly those with respiratory problems – to have medicines on hand and to limit outdoor activities.