Microbial Growth on Dust-Loaded Filtering Materials Used for the Protection of Respiratory Tract as a Factor Affecting Filtration Efficiency.

Katarzyna Majchrzycka,Anita Jachowicz,Justyna Szulc,Beata Gutarowska,Małgorzata Okrasa

doi:10.3390/ijerph15091902

Abstract

This work aims at understanding the effects of various dust-loading conditions and the type of nonwovens used in the construction of FFRs on the safe use of those protective devices in situations of exposure to biological agents. The survival of microorganisms (Escherichia coli, Candida albicans, and Aspergillus niger) in dust-loaded polypropylene nonwovens (melt-blown, spun-bonded, and needle-punched) was experimentally determined using microbiological quantitative method (AATCC TM 100-2004). Scanning electron microscope was used to assess biofilm formation on dust-loaded filtering nonwovens. The impact of the growth of microorganisms on filtration efficiency of nonwovens was analysed based on the measurements of penetration of sodium chloride particles (size range 7–270 nm). Results showed that tested microorganisms were able to survive on dust-loaded polypropylene filtering nonwovens. The survival rate of microorganisms and penetration of nanoparticles and submicron particles depended on the type of microorganism, as well as the type and the amount of dust, which indicates that both of those factors should be considered for FFR use recommendations.

Highlights

Harmful biological agents in the work environment can have infectious, toxic, and/or allergenic effects on the human body
The aim of the study was to evaluate the survival of selected microorganisms (Escherichia coli, Candida albicans, and Aspergillus niger) on the nonwovens used in the construction of filtering facepiece respirators (FFRs) in the presence of dust originating from work environments and determine how joined presence of dust and microorganisms may affect the filtration efficiency of such materials
E. coli, C. albicans, and A. niger, were able to survive on dust-loaded polypropylene filtering nonwovens

Summary

Introduction

Harmful biological agents in the work environment can have infectious, toxic, and/or allergenic effects on the human body They pose a high risk in a number of workplaces, including those in health care, laboratory, and veterinary facilities; agriculture, forestry, food, textile, mining, and wood industry; waste collection, sorting, and processing companies; art conservation and many others [1]. Most commonly, they are present in the environment as components of bioaerosol deposited on organic dust, which can be absorbed by the respiratory tract. The composition and cytotoxicity of dust in each of these places are different

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