Decontamination of Vegetation to Inactivate Bacillus anthracis Spores
Citation:
Wood, J., S. McDonald, A. Touati, T. Chamberlain, L. Oudejans, S. Serre, W. Calfee, AND E. Silvestri. Decontamination of Vegetation to Inactivate Bacillus anthracis Spores. Presented at US EPA 2023 Decontamination Conference, Charleston, SC, December 05 - 07, 2023.
Impact/Purpose:
The study described in this poster presentation was conducted under the AnCOR program, with the goal of assessing efficacy of decontamination options for vegetative materials contaminated with B. anthracis spores. For the decontaminants that were determined to be efficacious, subsequent tests were conducted to determine if any damage to plants occurred over a month after spraying them. Tests were conducted at bench and pilot scale, using a variety of small plants including evergreens, deciduous plants, ground cover, sod/grass, and pine tree bark. Efficacy tests were conducted using B. atrophaeus, a commonly used surrogate for B. anthracis decontamination studies. Other test variables included the use of several decontaminants and active ingredient concentrations. Initial tests showed that inoculation and recovery of spores from plant materials did not present any difficulties. Efficacy results showed that peracetic acid (PAA) was generally the most effective decontaminant for vegetative materials, followed by dichlor. (PAA was evaluated since some commercial off-the-shelf pesticides used for plants and crops have PAA as their active ingredient.) Pine bark was the most difficult material to effectively decontaminate. Simple phytotoxicity tests were conducted to assess any detrimental impacts of the decontaminants, such as leaf discoloration, leaf loss, and lack of growth. While none of the plants died during the month-long observations following exposure to the decontaminant, there were some mixed results with respect to other phytotoxic effects that varied by plant and decontaminant. No obvious trends in effects were noted. Based on the lab study results, the AnCOR Wide Area Demonstration selected PAA for decontaminating the vegetation on the test site.
Description:
The Analysis for Coastal Operational Resiliency (AnCOR) program is an interagency collaboration between the U.S. Environmental Protection Agency (EPA), the Department of Homeland Security (DHS), and the United States Coast Guard (USCG). The overall purpose of this multiagency program is to develop and demonstrate capabilities and strategic guidelines to prepare the U.S. for a wide-area release of a biological agent, including mitigating effects on USCG facilities and assets. Following a wide-area release of B. anthracis spores, vegetation may become contaminated with the biological agent. Decontamination of vegetative materials such as trees, grass, and crops, especially on a large scale, will be a challenge, due to the organic nature of vegetative materials, and the potentially large and complicated surface areas of foliage. Other challenges include effectively decontaminating the plants without killing or damaging them. The study described in this poster presentation was conducted under the AnCOR program, with the goal of assessing efficacy of decontamination options for vegetative materials contaminated with B. anthracis spores.