Finished basements in twenty-seven Ottawa houses were investigated to determine if the basement assemblies could contribute to poor indoor air quality due to molds. The wall cavities were inspected with optical fibrescopes to determine the composition and note the conditions. Visible mold colonies were sampled to identify mold species. The presence of molds correlated with the presence of chronic wetting events rather than any particular basement finishing techniques. Molds were analyzed from 16 (59%) of the houses and toxigenic molds were found in all houses except one.

Data on moisture sources, winter condensation potential, C02 levels, levels of biological contamination and blood lymphocytes from fifty nine houses subjected to detailed testing and inspection in a previous phase of the Wallaceburg study were subject to more detailed statistical evaluation to determine the relationships between moisture sources, fungal growth and objective measures of health.