Q-171. Aerosolization of Fungi, (1→3)-β-D Glucan, and Endotoxin from Materials Collected in New Orleans Homes after Hurricanes Katrina and Rita

A. Adhikari¹, J. Jung², T. Reponen¹, J. S. Lewis³, E. C. DeGrasse³, L. F. Grimsley³, G. L. Chew⁴, S. A. Grinshpun¹;
¹Univ. of Cincinnati, Cincinnati, OH, ²Korea Advanced Inst. of Sci. and Technology, Daejeon, REPUBLIC OF KOREA, ³Tulane Univ., New Orleans, LA, ⁴Columbia Univ., New York, NY.

Background: Exposures to airborne microorganisms, (1→3)-β-D glucan, and endotoxin are associated with adverse respiratory health effects. Microbial contamination has been very high in the standing water and sediments in homes flooded by hurricanes Katrina and Rita. At the same time, aerosolization from contaminated flood-affected materials remaining in these homes has not yet been investigated. Methods: Aerosolization of fungi, (1→3)-β-D glucan, and endotoxin from eight flood-affected floor and bedding materials collected in New Orleans homes were examined using the Fungal Spore Source Strength Tester (FSSST) in combination with a BioSampler. For comparison dust samples were collected from these materials by vacuuming. A NIOSH-developed 2-stage cyclone sampler was utilized to study the size-selective aerosolization of (1→3)-β-D glucan and endotoxin from five selected materials. Results: The average concentrations of aerosolized viable fungi (detected in five materials only) and total fungi were (6.22 ± 11.02) × 10⁶ CFU/m² and (6.66 ± 4.82) × 10⁵ spores/m², respectively. Average levels of aerosolized (1→3)-β-D glucan and endotoxin in all materials were (12.63 ± 9.82) × 10³ ng/m² and (2.76 ± 3.33) × 10⁴ EU/m², respectively. Conclusions: Significantly higher levels of aerosolized (1→3)-β-D glucan and endotoxin were observed in the tested materials. (1→3)-β-D glucan and endotoxin levels correlated significantly and <1.8µm particle size fraction showed concentration levels comparable to >1.8 µm particles for both biocontaminants. Since finer particles can be inhaled deeper into airways, this finding raises additional inhalation exposure concerns. Short sampling periods of 5 min for endotoxin and 15 min for fungi and (1→3)-β-D glucan appeared to be sufficient for assessing aerosolization potential with the FSSST. Vacuuming may overestimate inhalation exposure risks for (1→3)-β-D glucan and endotoxin as detected by the FSSST. The obtained results will complement previous studies on the exposures to bioaerosols in flooded homes.