Lasers help ash analysis

A Durham University researcher is using laser technology to analyse the particle size of volcanic ash and estimate its potential risk to human health


A Durham University researcher is using laser technology to analyse the particle size of volcanic ash and estimate its potential risk posed to human health.



Dr Claire Horwell, of the university’s Institute of Hazard and Risk Research, has developed a sieving technique which analyses the grain size of volcanic ash to determine its possible threat to many thousands of humans affected by the estimated 70 volcanic eruptions which happen worldwide each year.



Her research, funded by UK Natural Environment Research Council (NERC) and published in the Journal of Environmental Monitoring, could help shape emergency response plans following a volcanic eruption and cut the possible risk to human health posed by breathing in fine particles of ash.



In many countries only basic sieves are available for assessing the grain size of volcanic ash, but until now sieving could not determine if particles were fine enough to enter the lung.



To solve this problem, Horwell used laser technology to analyse the grain size of samples from around the world.



She found there was a strong link between the ratios of different-sized particles present. She then used this link to develop a formula so the amount of breathable particles could be estimated by sieving.



This sieving technique could allow emergency response teams to quickly and cheaply measure the potential risk to health without the need for high-tech equipment. Depending on the risk, measures could be put in place to protect people living close-by.



Horwell, who is also co-ordinator of the International Volcanic Health Hazard Network, said: ‘We need a rapid way to assess the hazard to human health from volcanic ash.



‘This technique means that scientists can sieve the ash then very quickly work out what percentage of the material could enter the lung.



‘If only a very small percentage of the ash is capable of entering the lung then it is unlikely to present a health hazard, but if there is a high percentage then you would want to issue dust masks or think about evacuating people from the surrounding area.’



Dr Horwell is also recommending that a network of ash collection sites be set up prior to an eruption so that a rapid assessment of health hazards can be made across a region.