Assessment of the Performance of Iodine-Treated Biocidal Filters and Characterization of Virus Aerosols
Abstract
Enhanced awareness of the threat of biological warfare and the spread of airborne pathogens has stimulated interest in bioaerosols and the need to develop better methods for respiratory protection. Among pathogens, viruses and bacterial spores are of special concern because they exhibit resistance to inactivation, small (highly penetrating) particle size and low median infectious dose. This study compared the mechanical and total viable removal by a relatively inefficient (~N50) iodine-treated biocidal filter challenged with aerosols of Bacillus subtilis spores and MS2 bacteriophage as surrogates for human pathogenic biological agents. The fate of viral aerosols influenced by environmental conditions and the spray medium were investigated by assessing infectious and total MS2 penetrating as a function of particle size, by comparing data from bioassay and polymerase chain reaction. The iodine-treated electret filter has an viable removal efficiency for bacterial spores with a negligible pressure drop in various environmental conditions. Because of strong retention of bioparticles on the electret medium, inactivation of the collected spores is only slightly enhanced by the presence of the iodinated resin. In the viral aerosol experiment, the iodine-treated filter also showed high biocidal performance. Both and induced capture of iodine by viral aerosols traversing the filter and dissociation of free I(sub 2) are mechanisms consistent with the inactivation by I(sub2) observed under our experimental conditions, which included a 3-ppm background concentration of I(sub2) in the liquid impingers used for particle collection. Impinger studies using bovine serum albumin as a competitor for I(sub2) and of thiosulfate as an I(sub2) quench showed that the inactivation process is not immediate and that at least half of the iodine acting as a disinfectant was captured by bioaerosols as they penetrated the filter medium.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 01, 2009
- Accession Number
- ADA506283
Entities
People
- Jin-hwa Lee
Organizations
- University of Florida