Volcanic ash: does it or does it not pose health risks?

Does the volcanic ash from Eyjafjallajokull hovering over Europe present health risks to the population on the ground? I mean health risks aside from the increase in stress levels, not to mention blood pressure, of those who got stranded because of flight cancellations.

According to a World Health Organization (WHO) statement on April 16, as long as the volcanic ash stays in the upper atmosphere, the health risks for those who are on the ground are minimal. However, in case of ash fall, there are health risks to people on the ground.

What’s blowing in the wind?

The US Geological Survey gives a general description of volcanic ash:

Small jagged pieces of rocks, minerals, and volcanic glass the size of sand and silt (less than 2 millimeters (1/12 inch) in diameter) erupted by a volcano are called volcanic ash. Very small ash particles can be less than 0.001 millimeters (1/25,000th of an inch) across. Volcanic ash is not the product of combustion, like the soft fluffy material created by burning wood, leaves, or paper. Volcanic ash is hard, does not dissolve in water, is extremely abrasive and mildly corrosive, and conducts electricity when wet.

Let us take a look at what is in this particular flying ash. Ongoing analysis by WHO shows that the Eyjafjallajokull ash consists about 25% of fine particulate matter smaller than 10 microns. Particles of this size, when inhaled, can penetrate deeper into the lungs.

Who is susceptible?

People suffering from chronic respiratory conditions like asthma, emphysema or bronchitis are susceptible to fine particulate matter. The usual preventive measures to mitigate respiratory problems are recommended including staying indoors, wearing protective masks, and avoiding strenuous physical exercise.

According to statement by Dr Maria Neira, Director of Public Health and Environment Department at WHO

“Particulate matter is identified according to its diameter. The small particulates less than 10 microns in size are more dangerous because they can penetrate deeper into the lungs. Since the ash concentration may vary from country to country depending on the wind and air temperatures, our advice is to listen to local public health officials for the best guidance for individual situations,” says Neira. “If people are outside and notice irritation in their throat and lungs, a runny nose or itchy eyes, they should return indoors and limit their outdoor activities.”

What should we do during ash fall?

Not all volcanic ash falls are the same just as no two volcanoes are the same. However, there are general guidelines from US Geological Survey for households, communities and businesses that in case of ash fall. The recommended lines of action are:

• Keep ash out of buildings, machinery, vehicles, downspouts, water supplies, and wastewater systems (for example, storm drains) as much as possible. The most effective method to prevent ash-induced damage to machinery is to shut down, close off or seal equipment until ash is removed from the immediate environment, but this may not be practical in all cases, especially for critical facilities.
• Minimize exposure to airborne ash by using dust or filter masks (or a wet cloth, for example a handkerchief) and minimizing travel.
• Coordinate clean-up activities with neighbors and community-wide operations (learn the clean-up guidelines and instructions of your local community and leaders). After an ash fall, promptly notify building owners to remove ash from roofs in a timely manner to prvent streets from being repetitively cleaned.
• Stay informed of volcanic activity in your area, especially during a period of unrest, and know what to expect, including the type of eruptions that can occur and how much warning is possible for ash fall in your area once an explosive eruption occurs. Learn about evacuation procedures, if any, in your area.
• Prepare for an emergency by having critical provisions and supplies needed to support your family, business, or community for at least several days; for example, food, water, medicine, and shelter, dust masks and other personal protection equipment, spare filters and parts for machinery and vehicles.
• Develop and test a contingency plan that can be used in a variety of emergencies, but not necessarily focused on volcanoes.
• Provide information frequently and directly to the public about volcanic ash, including instructions for participating in clean-up operations.

More details are available for downloading as pamphlets from the Volcanic Health Hazard Network (IVHHN):

• Volcanic health hazards of ash explained
• How to prepare and cope with ashfall