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Endotoxins: An indoor air and settled dust survey. J. Dobranic, Ph.D.* & S. Cappuccio, B.Sc. EMSL Analytical, Inc. www.emsl.com Tel: 800-220-3675 Email: jdobranic@emsl.com. Introduction. Evaluate and compare fungal contamination in air and surface samples with endotoxin in accumulated dust.
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Endotoxins: An indoor air and settled dust survey. J. Dobranic, Ph.D.* & S. Cappuccio, B.Sc. EMSL Analytical, Inc. www.emsl.com Tel: 800-220-3675 Email: jdobranic@emsl.com
Introduction • Evaluate and compare fungal contamination in air and surface samples with endotoxin in accumulated dust. • Dust may represent cumulative exposure to endotoxin.
Endotoxin • Pyrogenic, cell wall component (lipopolysaccharide) of Gram-negative bacteria. • Heat-stable
Endotoxin • Elevated airborne concentrations are prevalent in sewage treatment plants • swine operations • cotton textile mills • poultry houses • water damaged buildings
Health Effects • Produces airway inflammation (wheezing) • Associated with increased severity of child and adult asthma • Exposure during childhood may reduce allergic responses later in life • Cause of Humidifier Fever
Materials and Methods • Various fungal samples based on IAQ investigation. • Spore traps and surface samples
Materials & Methods • 12 homes sampled in NJ & PA. • 3 endotoxin samples collected in each dwelling • Kitchen floor, Sofa, Living Room floor, Bedroom floor, Bedroom bed, basement.
Materials & Methods • Specifications: • 0.45µm Polycarbonate Filter • 37mm Styrene Housing • Sterilized by Irradiation • Endotoxin Free • Sift dust through 350 micron sieve • Kinetic Chromogenic Limulus amoebocyte lysate (LAL) assay (EU – endotoxin units)
Results • Surface sample: • 9 out of 12 homes had visible mould growth inside (Aspergillus, Chaetomium, Penicillium, and Stachybotrys) • Spore traps: • 8 out of 12 had > indoor spore counts vs outdoors
Results • Endotoxin: • Mouldy: 0.1-263.6 EU/mg dust • Non-Mouldy: 0.5-38.5 EU/mg dust • Published range is 11-100 EU/mg dust
Conclusions • Mouldiness in homes was not a good predictor of endotoxin levels. • Similar conclusion in published studies comparing endotoxin in air with mouldiness. • Suspicion of GNB contamination requires directed endotoxin testing.
Endotoxin Predictors in Literature • Positively correlated with presence of a dog or past presence of a dog. • Positively correlated with use of a cool-mist humidifier • Negatively correlated with use of a dehumidifier.
Acknowledgements • Marc Leftwich and Bob Woodward at AMT Mold Testing in PA. • EMSL’s clients for participation.
Contact Information • Jason Dobranic, Ph.D. • EMSL Analytical, Inc. • 107 Haddon Ave. Westmont, NJ 08108 • Tel: 800-220-3675 • Email: jdobranic@emsl.com