Measuring the efficacy of mold remediation on contaminated ductwork

Published guidelines on mold remediation do not specify sampling protocols to measure the efficacy of remediation efforts. The purpose of this study was to evaluate fungal remediation of contaminated ducts by comparing the amount of residual surface contamination to the amount in new ducts. Fungal contamination of galvanized metal and rigid fibrous glass ducts were evaluated using fluorometric and microscopic methods. Fungal contamination was measured in newly installed ducts in addition to pre- and post-remediation. Newly installed ducts had low levels of fungal debris. Findings demonstrated that both fluorometry and microscopy methods detected fungal surface contamination. After cleaning, metal ducts were statistically less contaminated than when new. Fungal contamination of rigid fibrous glass ducts was reduced by ~90%, but was statistically more contaminated than when new. The fluorometric method performed as well as the microscopic method in detecting fungal contamination and provided faster results for monitoring efficacy of fungal remediation.