title: Endotoxin deposits on the inner surfaces of closed-face cassettes during bioaerosol sampling: a field investigation at composting facilities.
abstract: A set of 270 bioaerosol samples was taken from 15 composting facilities using polystyrene closed-face filter cassettes (CFCs). The objective was to measure the quantity of endotoxin deposits on the inner surfaces of the cassettes (sometimes referred to as 'wall deposits'). The results show that endotoxins are deposited on the inner surfaces of the CFCs through sampling and/or handling of samples. The quantity of endotoxins measured on inner surfaces range between 0.05 (the limit of detection of the method) and 3100 endotoxin units per cassette. The deposits can represent a large and variable percentage of the endotoxins sampled. More than a third of the samples presented a percentage of inner surface deposits >40% of the total quantity of endotoxins collected (filter + inner surfaces). Omitting these inner surface deposits in the analytical process lead to measurement errors relative to sampling all particles entering the CFC sampler, corresponding to a developing consensus on matching the inhalable particulate sampling convention. The result would be underestimated exposures and could affect the decision as to whether or not a result is acceptable in comparison to airborne concentration limits defined in terms of the inhalability convention. The results of this study suggest including the endotoxins deposited on the inner surfaces of CFCs during analysis. Further researches are necessary to investigate endotoxin deposits on the inner cassette surfaces in other working sectors.
authors.affiliation: 1.INRS - Institut National de Recherche et de Sécurité, Aerosols Metrology Laboratory, Pollutants Metrology Division, 1 rue du Morvan CS 60027, Vandœuvre-lès-Nancy Cedex 54519, France philippe.duquenne@inrs.fr.
authors.forename: Philippe
authors.initials: P
authors.lastname: Duquenne
authors.affiliation: 1.INRS - Institut National de Recherche et de Sécurité, Aerosols Metrology Laboratory, Pollutants Metrology Division, 1 rue du Morvan CS 60027, Vandœuvre-lès-Nancy Cedex 54519, France.
authors.forename: Xavier
authors.initials: X
authors.lastname: Simon
authors.affiliation: 1.INRS - Institut National de Recherche et de Sécurité, Aerosols Metrology Laboratory, Pollutants Metrology Division, 1 rue du Morvan CS 60027, Vandœuvre-lès-Nancy Cedex 54519, France.
authors.forename: Valérie
authors.initials: V
authors.lastname: Demange
authors.affiliation: 2.NIOSH - National Institute for Occupational Safety and Health, Health Effects Laboratory Division, 1095 Willowdale Road, Morgantown, WV 26505, USA.
authors.forename: Martin
authors.initials: M
authors.lastname: Harper
authors.affiliation: 1.INRS - Institut National de Recherche et de Sécurité, Aerosols Metrology Laboratory, Pollutants Metrology Division, 1 rue du Morvan CS 60027, Vandœuvre-lès-Nancy Cedex 54519, France.
authors.forename: Pascal
authors.initials: P
authors.lastname: Wild
mesh_terms: D000336:Aerosols / Q000032:analysis*; D000395:Air Pollutants, Occupational / Q000032:analysis; D004731:Endotoxins / Q000032:analysis*; D004784:Environmental Monitoring / Q000295:instrumentation* / Q000379:methods; D005374:Filtration; D016273:Occupational Exposure / Q000032:analysis; D013048:Specimen Handling; D064091:Waste Disposal Facilities
chemical_list: D000336:Aerosols; D000395:Air Pollutants, Occupational; D004731:Endotoxins
keywords: air sampling; bioaerosol; closed-face cassette; composting facilities; endotoxins; inner surfaces deposits; wall deposits