A Durham University study has found out that industry-certified particle masks are most effective at protecting people from volcanic ash.
The study which was led by Dr Claire Horwell of the Department of Earth Sciences and Institute of Hazard, Risk and Resilience (IHRR), has also pointed out that commonly used surgical masks offer less protection.
The study was undertaken in partnership with the Institute of Occupational Medicine (IOM) and the team hopes that their findings will inform responses to future volcanic eruptions.
As part of their research, the team tested a range of respiratory protection frequently used by communities affected by volcanic ash, including bandanas, surgical masks and the more sophisticated industry-certified ‘N95’ masks.
Volcanic ash is known to induce symptoms such as coughing, breathlessness and wheezing, and could as well as exacerbate pre-existing conditions such as asthma and bronchitis.
Recommendations from this project have already been applied in Bali and Hawaii, where local Non-Governmental Organisations and governmental agencies distributed N95 masks based on the project findings.
In the first phase of the study, the researchers tested the filtration efficiency (FE) of mask materials.
During testing of 17 commonly used forms of respiratory protection the team found that industry-certified masks – effective at blocking fine particles known as PM2.5 – and a very basic mask from Indonesia achieved high levels of FE.
In contrast, cloth protection such as bandanas, offered a poor FE. Wetting materials did not help improve their performance, although folding the material did help – a little.
The second phase of the study assessed the facial fit of four types of mask with the best filtration efficiency results, to understand how Total Inward Leakage (TIL) affected effectiveness.
Volunteers wore each type of respiratory protection during a simulation of volcanic ash clean-up activities, whilst the research team measured TIL.
Whilst the industry-certified N95 masks achieved a good TIL result, surgical masks – which are commonly distributed during volcanic ashfall – were found to have more inward leakage due to their poor facial fit.
Image credits and content: Pexels/Durham University