Effect of Chlorine Dioxide Gas on Fungi and Mycotoxins Associated with Sick Building Syndrome

Abstract

APPLIED AND ENVIRONMENTAL MICROBIOLOGY, Sept. 2005, p. 5399–5403 Vol. 71, No. 9 0099-2240/05/$08.00
0 doi:10.1128/AEM.71.9.5399–5403.2005 Copyright © 2005, American Society for Microbiology. All Rights Reserved. Effect of Chlorine Dioxide Gas on Fungi and Mycotoxins Associated with Sick Building Syndrome S. C. Wilson,* C. Wu, L. A. Andriychuk, J. M. Martin, T. L. Brasel, C. A. Jumper, and D. C. Straus Center for Indoor Air Research, Department of Microbiology and Immunology, Health Sciences Center, Texas Tech University, Lubbock, Texas 79430 Received 28 October 2004/Accepted 28 March 2005 The growth of indoor molds and their resulting products (e.g., spores and mycotoxins) can present health hazards for human beings. The efficacy of chlorine dioxide gas as a fumigation treatment for inactivating sick building syndrome-related fungi and their mycotoxins was evaluated. Filter papers (15 per organism) featuring growth of Stachybotrys chartarum, Chaetomium globosum, Penicillium chrysogenum, and Cladosporium cladospo- rioides were placed in gas chambers containing chlorine dioxide gas at either 500 or 1,000 ppm for 24 h. C. globosum was exposed to the gas both as colonies and as ascospores without asci and perithecia. After treatment, all organisms were tested for colony growth using an agar plating technique. Colonies of S. chartarum were also tested for toxicity using a yeast toxicity assay with a high specificity for trichothecene mycotoxins. Results showed that chlorine dioxide gas at both concentrations completely inactivated all organ- isms except for C. globosum colonies which were inactivated an average of 89%. More than 99% of ascospores of C. globosum were nonculturable. For all ascospore counts, mean test readings were lower than the controls (P < 0.001), indicating that some ascospores may also have been destroyed. Colonies of S. chartarum were still toxic after treatment. These data show that chlorine dioxide gas can be effective to a degree as a fumigant for