Devastating effects of hurricane Katrina and of the subsequent flooding on New Orleans LA and surrounding areas are well-known.  When the flood waters receded, the submerged houses and their contents were found to be covered with molds.  Over 100 samples of water damaged organic material from homes in New Orleans, LA, collected in October 2005 or July 2006 were plated on Czapecks solution agar supplemented with antibacterial agents and incubated for a minimum of one week.  Resultant mold colonies displaying different morphologies were subcultured until a pure culture was obtained and then identified to genus level by standard microscopic and cultural approaches.   The following genera of molds were found:  Aspergillus (23 strains), Cladosporium (1 strain), Penicillium (13 strains) and Trichoderma (40 strains).  To conduct a preliminary survey of volatile organic compounds (VOCs) produced by a Penicillium sp. and Trichoderma longbrachiatum, the cultures were grown on potato dextrose agar medium in a closed system and the collected VOCs were flushed out with air.  The VOCs were adsorbed on a Tenax TA resin and analyzed by GS-MS. From this analysis more than 30 different compounds were putatively identified.  Subsequently, the same strains were grown on water-saturated dry wall in a model laboratory habitat; the samples were collected and assayed as described above.  The major VOCs detected were 2-ethyl-hexanal, bicyclo[4,2]octa-1,3,5-triene, octanol, 1,2-dimethyl-benzene, 1,2,4-trimethyl-benzene, limonene. For the determination of the biological activity, these VOCs were dissolved in a biocompatible solvent, e.g. ethanol, in a cryo-trap, concentrated and analyzed in a bio-assay with Caenorhabditis elegans.