Volcanic ash is the mineral particles spread by volcanic eruptions. Particle size varies, but when inhaled, only the smallest particles (<10 microns) may cause adverse health effects. The harmful effect of particles may vary, depending on the origin of the volcanic ash.
The volcanic ash can consist of irritants like fluoride and sulphur, in addition to small amounts of quartz, which in a long perspective may cause lung damage. At this point we do not know in detail the constituents of the volcanic ash from this eruption, but we are working to find out more.
Health effects of volcanic ash such as irritation of eyes, nasal mucous membranes and respiratory tract, have previously been reported primarily in areas close to the volcanic eruption. Vulnerable groups are people with lung diseases such as asthma and COPD, heart disease and children.
The ash plume from Iceland has mainly moved in the upper air layers. Potential human health risk occurs only when the volcanic ash reaches the ground, depending on the amount of volcanic ash in the air.
Precipitation can bring the ashes down from the upper air layers, but can reduce the amount of particles that will be inhaled.
“It may be necessary to advise that particularly vulnerable groups should stay indoors when harmful quantities are found near the ground,” Department Director Per Scwarze at the Norwegian Institute of Health says.
This is the same advice regularly given to the population in major cities when air pollution is high (www.luftkvalitet.info). As for now special advice or action is not applicable.
“Health authorities will monitor the pollution situation closely and provide advice to the public in the event of harmful amounts of volcanic ash in the air at ground level,” Schwarze says.
The Norwegian Directorate of Health will coordinate the health authorities' handling of the situation.