You are here:
Comparison of DNATrax and Bacillus anthracis Surrogate Resuspension from Subway Surfaces
Archer, J., D. Hook, R. Yaga, W. Calfee, K. Ratliff, L. Mickelsen, J. Gilberry, AND K. McConkey. Comparison of DNATrax and Bacillus anthracis Surrogate Resuspension from Subway Surfaces. U.S. Environmental Protection Agency, Washington, DC, EPA/600/R-20/113, 2020.
The results of these re-suspension fraction comparison experiments provided information under what conditions an inert sugar-based surrogate is a suitable stimulant for a biological agent when comparing re-suspension from two common subway surfaces. It was observed that DNATrax under environmental conditions below 80% humidity can be viewed as statistically similar to BTK, and subsequently Ba, when considering re-suspension from representative conditions and these two surfaces present in subway systems. This has important implications for past and future field studies in which DNATrax was used as a spore simulant. This research assists with understanding the spread of biological contaminants due to a bio-terrorism incident after the contaminants settle onto surfaces in an urban environment, which is of utmost importance to respondents and decisions makers following such an incident.
The main objective of this study was to compare the re suspension of an inert sugar-based surrogate, known as DNA Tagged Reagents for Aerosol Experiments (DNATrax) developed by Lawrence Livermore National Laboratory (LLNL) under variable humidity conditions for an underground subway system to the re-suspension of an established biological surrogate of Bacillus anthracis (Bacillus thuringiensis var. kurstaki [Btk]). The two surrogates were deposited on representative porous and nonporous subway surfaces, and we determined under what conditions, if any, DNATrax is an appropriate surrogate for Bacillus anthracis (Ba) when re-suspension is considered. A dry powder micro-educator deposition system was developed to accurately and repeatedly deposit the materials at the desired coupon load, spatial distribution, and with the majority of particles in their singlet and doublet forms with reduced agglomeration.