Resistance of Commercial Bed Covers against Faecal Pellets of House Dust Mites: Behaviour of Seams and Zippers

Abstract

This study evaluated the allergen impermeability against airborne allergens of dust mite droppings through all parts of commercial bed covers, including surface seams and zippers. Specimens were taken from places with and without seams and zipper. A novel penetration cell was developed to expose the specimens to an inoculum of purified mite droppings that was assessed for its allergen content Der p1 prior to the penetration tests. Using covers of different construction and material, the penetration level increased significantly in the presence of seams and zippers and could reach up to 6% depending on the seam's/zipper's characteristics and quality. Therefore, zippers and seams have to be considered as access points for the penetration of mite droppings. As for the penetration of airborne mite particles through the zipper, the penetration level was greatly attenuated by the presence of a cover strip. Depending on the respective quality and the construction type, the mite allergen Der p1 penetrated most likely through the zipper and seams of the specimens, already after a single laundry cycle. Hence, laundry may compromise the barrier performance and proves to be an important quality feature. In all samples, the textile surface showed sufficient allergen impermeability. Our conclusions provide recommendations to both manufacturers and users.

Cellulose‐based micro‐fibrous materials imaged with a home‐built smartphone microscope

“…Although, the method presented here is limited to thin samples, still there are range of materials and processes that could be imaged and characterized with the system; such as (a) surface porosity of adsorbent materials, (b) microscopic defects and porosity in membrane filters, (c) cracks and their formation in ceramic materials, (d) morphological characterization of suspended particulate matters, (e) filler distribution in composite materials and many more. Another interesting application could be the study of dust mite droppings that are known to cause allergic problems when lodged in bed coverings (Höfer, Berner‐Dannenmann, Marquardt, & Hammer, 2019).…”

“…system; such as (a) surface porosity of adsorbent materials, (b) microscopic defects and porosity in membrane filters, (c) cracks and their formation in ceramic materials, (d) morphological characterization of suspended particulate matters, (e) filler distribution in composite materials and many more. Another interesting application could be the study of dust mite droppings that are known to cause allergic problems when lodged in bed coverings(Höfer, Berner-Dannenmann, Marquardt, & Hammer, 2019).F I G U R E 5Surface images of mechanically pulped paper and a three ply surgical facemask. (a) Representative surface image of a mechanically pulped paper imaged with a smartphone and (b) bright field microscope.…”