At the Institute of Occupational Medicine, Edinburgh, in their PPE labs., we will investigate the effectiveness of different forms of respiratory protection through two trials:

a) Filtration efficiency. Samples collected from Yogyakarta during the Kelud eruption crisis (from clothing to surgical masks, bandanas to scooter masks) and high-efficiency facemasks (N95/FFP2or3) will be tested for filtration efficiency against volcanic ash (2 types) and a matching, non-toxic surrogate dust (e.g. TiO2), focusing on particles sub 2.5 microns diameter. A dummy head and breathing simulator will be used and dust concentrations will be measured inside and outside the masks (15 masks, 2 breathing rates, 2 dust concentrations, 3 replicates). Mass loading tests will also be conducted to assess the effectiveness of the masks over time.

b) ‘Real-life’ effectiveness. 8 adult subjects (4 male, 4 female), with various facial characteristics (measured to British Standard EN136:1998) including facial hair/small faces to represent children, will undertake realistic activities (e.g., sweeping ‘ash’) whilst exposed to a non-toxic surrogate dust. Dust concentrations will be sampled inside and outside of the masks (4 masks, based on results of (a), 2 activities, 2 replicates).

The most successful masks from the laboratory experiments will be delivered to Sakurajima, Japan (where ashfall is guaranteed) for wearability testing by 20-30 local subjects. Questionnaire on perceptions of effectiveness compared to their normal interventions will be completed.