Airborne mold and endotoxin concentrations in New Orleans, Louisiana, after flooding, October through November 2005.
BACKGROUND
The hurricanes and flooding in New Orleans, Louisiana, in October and November 2005 resulted in damp conditions favorable to the dispersion of bioaerosols such as mold spores and endotoxin.


OBJECTIVE
Our objective in this study was to assess potential human exposure to bioaerosols in New Orleans after the flooding of the city.


METHODS
A team of investigators performed continuous airborne sampling for mold spores and endotoxin outdoors in flooded and nonflooded areas, and inside homes that had undergone various levels of remediation, for periods of 5-24 hr during the 2 months after the flooding.


RESULTS
The estimated 24-hr mold concentrations ranged from 21,000 to 102,000 spores/m3 in outdoor air and from 11,000 to 645,000 spores/m3 in indoor air. The mean outdoor spore concentration in flooded areas was roughly double the concentration in nonflooded areas (66,167 vs. 33,179 spores/m3 ; p < 0.05) . The highest concentrations were inside homes. The most common mold species were from the genera of Cladosporium and Aspergillus/Penicillium ; Stachybotrys was detected in some indoor samples. The airborne endotoxin concentrations ranged from 0.6 to 8.3 EU (endotoxin units) /m3 but did not vary with flooded status or between indoor and outdoor environments.


CONCLUSIONS
The high concentration of mold measured indoors and outdoors in the New Orleans area is likely to be a significant respiratory hazard that should be monitored over time. Workers and returning residents should use appropriate personal protective equipment and exposure mitigation techniques to prevent respiratory morbidity and long-term health effects.
Solomon
Gina M
GM
Natural Resources Defense Council, San Francisco, California, USA. gsolomon@nrdc.org
Hjelmroos-Koski
Mervi
M
Rotkin-Ellman
Miriam
M
Hammond
S Katharine
SK
D016902:Air Pollution, Indoor / Q000009:adverse effects / Q000032:analysis*; D000818:Animals; D001230:Aspergillus / Q000254:growth & development / Q000302:isolation & purification; D002963:Cladosporium / Q000254:growth & development / Q000302:isolation & purification; D004190:Disasters; D004731:Endotoxins / Q000032:analysis*; D004781:Environmental Exposure / Q000009:adverse effects / Q000032:analysis*; D004784:Environmental Monitoring; D006798:Housing; D006801:Humans; D008145:Louisiana; D008685:Meteorological Concepts; D010407:Penicillium / Q000254:growth & development / Q000302:isolation & purification; D011634:Public Health; D013170:Spores / Q000254:growth & development / Q000302:isolation & purification / Q000502:physiology*; D013191:Stachybotrys / Q000254:growth & development / Q000302:isolation & purification; D013997:Time Factors
D004731:Endotoxins