Aerosolization of fungi, (1-->3)-beta-D glucan, and endotoxin from flood-affected materials collected in New Orleans homes.

ABSTRACT

Standing water and sediments remaining on flood-affected materials were the breeding ground for many microorganisms in flooded homes following Hurricane Katrina. The purpose of this laboratory study was to examine the aerosolization of culturable and total fungi, (1-->3)-beta-D glucan, and endotoxin from eight flood-affected floor and bedding materials collected in New Orleans homes, following Hurricane Katrina. Aerosolization was examined using the Fungal Spore Source Strength Tester (FSSST) connected to a BioSampler. Dust samples were collected by vacuuming. A two-stage cyclone sampler was used for size-selective analysis of aerosolized glucan and endotoxin. On average, levels of culturable fungi ranged from undetectable (lower limit=8.3 x 10(4)) to 2.6 x 10(5) CFU/m(2); total fungi ranged from 2.07 x 10(5) to 1.6 x 10(6) spores/m(2); (1-->3)-beta-D glucan and endotoxin were 2.0 x 10(3) - 2.9 x 10(4) ng/m(2) and 7.0 x 10(2) - 9.3 x 10(4) EU/m(2), respectively. The results showed that 5-15 min sampling is sufficient for detecting aerosolizable biocontaminants with the FSSST. Smaller particle size fractions (<1.0 and <1.8 microm) have levels of glucan and endotoxin comparable to larger (>1.8 microm) fractions, which raises additional exposure concerns. Vacuuming was found to overestimate inhalation exposure risks by a factor of approximately 10(2) for (1-->3)-beta-D glucan and by 10(3)-10(4) for endotoxin as detected by the FSSST. The information generated from this study is important with respect to restoration and rejuvenation of the flood-affected areas in New Orleans. We believe the findings will be significant during similar disasters in other regions of the world including major coastal floods from tsunamis.