Indoor Fungi
...ically ventilated air systems. Standards on what are acceptable levels of bioaerosol fungi vary, however, for toxigenic species such as Stachybotrys and Fusarium, the nationally accepted levels are less than 50 colonies of fungal units per meter cubed (<50 c.f.u. /m^3) of a single species. For total fugal populations the cap is <1000 c.f.u.’s /m^3. Amounts greater than that are acceptable indicators of the presence of an indoor fungus. However, even concentrations greater than 200 c.f.u.’s /m^3 require further evaluation. The results found 81% of the classrooms had >150 c.f.u.’s /m^3, and 35% had >500 c.f.u.’s /m^3. Mechanically ventilated air had less c.f.u. /m ^3 of than naturally ventilated air. However, other factors in accounting for the measured c.f.u.’s were the time of year and outdoor temperature. In a naturally ventilated classroom the I/O was smaller compared to a mechanically ventilated room for the same location at the same time perio...