Title
Optimization of airborne endotoxin exposure assessment: Effects of filter type, transport conditions, extraction solutions, and storage of samples and extracts
Author
TNO Kwaliteit van Leven
Spaan, S.
Heederik, D.J.J.
Thorne, P.S.
Wouters, I.M.
Publication year
2007
Abstract
Endotoxin exposure occurs in homes and occupational environments and is known to cause adverse health effects. In order to compare results from different studies and establish standards, airborne endotoxin exposures should be assessed using standardized methods. Although the European Committee for Standardization (CEN) developed guidelines for endotoxin exposure assessment, these leave room for individual interpretation. The influence of methods of sampling, extraction, and analysis has never been investigated in a full experimental design. Thus, we sought to fully elucidate the importance of all facets of endotoxin assessment. Inhalable dust samples collected simultaneously were used to investigate the effects on and interactions with airborne endotoxin concentration in two working environments of filter type (glass fiber or Teflon), transport conditions (with/without desiccant), sample storage (-20 or 4°C), extraction solution (pyrogen-free water [PFW] or PFW plus 0.05% Tween 20), extract storage (-20 or 4°C), and assay solution (PFW or PFW plus 0.05% Tween 20). Four hundred samples were collected and randomly distributed over the 20 combinations of treatments. There were no differences found for transport conditions and storage temperature of extracts. Also, no interactions between study variables existed. Sampling on glass-fiber filters, storage of samples in the freezer, and extraction in PFW plus 0.05% Tween 20 resulted in 1.3-, 1.1-, and 2.1-fold-higher estimated endotoxin concentrations, respectively. Use of PFW plus 0.05% Tween 20 in the assay solution had an additive effect. Thus, this study investigated gaps in the CEN protocol and provides data with which to fully specify a protocol for standardization of endotoxin exposure assessment. Copyright © 2007, American Society for Microbiology. All Rights Reserved.
Subject
Food and Chemical Risk Analysis
Extraction
Glass fibers
Microbiology
Optimization
Polytetrafluoroethylenes
Sampling
Airborne endotoxin exposure
Assay solution
Extraction solutions
Filter type
Toxicity
endotoxin
glass
politef
air quality
dust
environmental impact assessment
experimental design
guideline
health impact
pollution exposure
standard (regulation)
toxin
air monitoring
air sampling
airborne particle
article
environmental exposure
extraction
filter
indoor air pollution
nonhuman
process optimization
standardization
transport kinetics
Air Pollutants
Air Pollutants, Occupational
Endotoxins
Filtration
Specimen Handling
To reference this document use:
http://resolver.tudelft.nl/uuid:8e4b9b79-9412-472e-a816-c5251b753a15
DOI
https://doi.org/10.1128/aem.00851-07
TNO identifier
240234
ISSN
0099-2240
Source
Applied and Environmental Microbiology, 73 (73), 6134-6143
Document type
article