Evaluation of swabs and transport media for the recovery of Yersinia pestis.

The Government Accountability Office report investigating the surface sampling methods used during the 2001 mail contamination with Bacillus anthracis brought to light certain knowledge gaps that existed regarding environmental sampling with biothreat agents. Should a contamination event occur that involves non-spore forming biological select agents, such as Yersinia pestis, surface sample collection and processing protocols specific for these organisms will be needed. Two Y.

Comparative evaluation of vacuum-based surface sampling methods for collection of Bacillus spores.

In this study, four commonly-used sampling devices (vacuum socks, 37 mm 0.8 μm mixed cellulose ester (MCE) filter cassettes, 37 mm 0.3 μm polytetrafluoroethylene (PTFE) filter cassettes, and 3M™ forensic filters) were comparatively evaluated for their ability to recover surface-associated spores.

Environmental persistence of vaccinia virus on materials.

Smallpox is caused by the variola virus, and ranks as one of the most serious diseases that could originate from a biological weapon. However, limited data exist on the persistence of variola and related viruses on materials (that may act as fomites), under controlled environmental conditions. To fill these data gaps, we determined the persistence of the vaccinia virus (an established surrogate for the variola virus) as a function of temperature, relative humidity and material.

Evaluation of peracetic acid fog for the inactivation of Bacillus anthracis spore surrogates in a large decontamination chamber.

The purpose of this study was to evaluate the sporicidal (inactivation of bacterial spores) effectiveness and operation of a fogging device utilizing peracetic acid/hydrogen peroxide (PAA). Experiments were conducted in a pilot-scale 24 m(3) stainless steel chamber using either biological indicators (BIs) or bacterial spores deposited onto surfaces via aerosolization. Wipe sampling was used to recover aerosol-deposited spores from chamber surfaces and coupon materials before and after fogging to assess decontamination efficacy.

Evaluation of surface sampling for Bacillus spores using commercially available cleaning robots.

Five commercially available domestic cleaning robots were evaluated on their effectiveness for sampling aerosol-deposited Bacillus atrophaeus spores on different indoor material surfaces. The five robots tested include three vacuum types (R1, R2, and R3), one wet wipe (R4), and one wet vacuum (R5). Tests were conducted on two different surface types (carpet and laminate) with 10(6) colony forming units of B.

A rapid and repeatable method to deposit bioaerosols on material surfaces.

A simple method for repeatably inoculating surfaces with a precise quantity of aerosolized spores was developed. Laboratory studies were conducted to evaluate the variability of the method within and between experiments, the spatial distribution of spore deposition, the applicability of the method to complex surface types, and the relationship between material surface roughness and spore recoveries. Surface concentrations, as estimated by recoveries from wetted-wipe sampling, were between 5×10(3) and 1.

Wipe selection for the analysis of surface materials containing chemical warfare agent nitrogen mustard degradation products by ultra-high pressure liquid chromatography-tandem mass spectrometry.

Degradation products arising from nitrogen mustard chemical warfare agent were deposited on common urban surfaces and determined via surface wiping, wipe extraction, and liquid chromatography–tandem mass spectrometry detection. Wipes investigated included cotton gauze, glass fiber filter, non-woven polyester fiber and filter paper, and surfaces included several porous (vinyl tile, painted drywall, wood) and mostly non-porous (laminate, galvanized steel, glass) surfaces. Wipe extracts were analyzed by ultra-high pressure liquid chromatography–tandem mass spectrometry (UPLC–MS/MS) and compared with high performance liquid chromatography–tandem mass spectrometry (HPLC–MS/MS) results.

Inactivation of vegetative bacterial threat agents on environmental surfaces.

Following a wide-area biological terror attack, numerous decontamination technologies, techniques, and strategies will be required for rapid remediation. Establishing an understanding of how disinfectants will perform under field conditions is of critical importance. The purpose of this study was to determine the efficacy of several liquid decontaminants, when used to inactivate vegetative biological agents on environmental surfaces.

Benchmark dose analysis for Bacillus anthracis inhalation exposures in the nonhuman primate.

There is considerable variability in the published lethality values for inhalation exposures of Bacillus anthracis. The lack of consensus on an acceptable dose-response relationship poses a significant challenge in the development of risk-based management approaches for use following a terrorist release of B. anthracis spores.

The effects of environmental conditions on persistence and inactivation of Brucella suis on building material surfaces.

Aims: The purpose of this study was to evaluate the effects of environmental conditions and material type on persistence and inactivation of Brucella suis.

Methods And Results: Brucella suis (approx. 1 × 10(8) CFU) was spiked onto surfaces (glass, aluminium and wood) by liquid inoculation.

Laboratory evaluation of large-scale decontamination approaches.

Aims: To evaluate the effectiveness of two spray-based decontamination methods for surface contamination reduction and to determine the potential for contamination spread by these methods.

Methods And Results: Material coupons (treated plywood and concrete) were contaminated with c. 1 × 10(7) spores of Bacillus atrophaeus by aerosol deposition.

Germinant-enhanced decontamination of Bacillus spores adhered to iron and cement-mortar drinking water infrastructures.

Germination was evaluated as an enhancement to decontamination methods for removing Bacillus spores from drinking water infrastructure. Germinating spores before chlorinating cement mortar or flushing corroded iron was more effective than chlorinating or flushing alone.

Guidelines for the identification of unknown samples for laboratories performing forensic analyses for chemical terrorism.

Since the early 1990s, the FBI Laboratory has sponsored Scientific Working Groups to improve discipline practices and build consensus among the forensic community. The Scientific Working Group on the Forensic Analysis of Chemical, Biological, Radiological and Nuclear Terrorism developed guidance, contained in this document, on issues forensic laboratories encounter when accepting and analyzing unknown samples associated with chemical terrorism, including laboratory capabilities and analytical testing plans. In the context of forensic analysis of chemical terrorism, this guidance defines an unknown sample and addresses what constitutes definitive and tentative identification.

Optimizing acidified bleach solutions to improve sporicidal efficacy on building materials.

Aims: We evaluated whether lowering pH (with acetic acid) and raising free available chlorine (FAC) levels in bleach solutions would improve efficacy in inactivating Bacillus spores on different materials. We also determined how varying pH and FAC levels affected bleach stability.

Methods And Results: Acidified bleach solutions with pH levels of 4.

Efficacy of liquid spray decontaminants for inactivation of Bacillus anthracis spores on building and outdoor materials.

Aims: To obtain data on the efficacy of various liquid and foam decontamination technologies to inactivate Bacillus anthracis Ames and Bacillus subtilis spores on building and outdoor materials.

Methods And Results: Spores were inoculated onto test coupons and positive control coupons of nine different materials. Six different sporicidal liquids were spray-applied to the test coupons and remained in contact for exposure times ranging from 10 to 70 min.

Adsorption of chlorine dioxide gas on activated carbons.

Research and field experience with chlorine dioxide (ClO2) gas to decontaminate structures contaminated with Bacillus anthracis spores and other microorganisms have demonstrated the effectiveness of this sterilant technology. However, because of its hazardous properties, the unreacted ClO2, gas must be contained and captured during fumigation events. Although activated carbon has been used during some decontamination events to capture the ClO2 gas, no data are available to quantify the performance of the activated carbon in terms of adsorption capacity and other sorbent property operational features.

Evaluation of surface sampling techniques for collection of Bacillus spores on common drinking water pipe materials.

Drinking water utilities may face biological contamination of the distribution system from a natural incident or deliberate contamination. Determining the extent of contamination or the efficacy of decontamination is a challenge, because it may require sampling of the wetted surfaces of distribution infrastructure. This study evaluated two sampling techniques that utilities might use to sample exhumed pipe sections.

Dry thermal resistance of Bacillus anthracis (Sterne) spores and spores of other Bacillus species: implications for biological agent destruction via waste incineration.

Aims: To obtain needed data on the dry thermal resistance of Bacillus anthracis spores and other Bacillus species for waste incinerator applications.

Methods And Results: Tests were conducted in a pilot-scale incinerator utilizing biological indicators comprised of spores of Geobacillus stearothermophilus, Bacillus atrophaeus and B. anthracis (Sterne) and embedded in building material bundles.

Health-based Provisional Advisory Levels (PALs) for homeland security.

The Homeland Security Presidential Directive #8 (HSPD-8) for National Emergency Preparedness was issued to " establish policies to strengthen the preparedness of the United States to prevent and respond to threatened or actual domestic terrorist attacks, major disasters, and other emergencies by requiring a national domestic all- hazards preparedness goal. "In response to HSPD-8 and HSPD-22 (classified) on Domestic Chemical Defense, the US Environmental Protection Agency (US EPA) National Homeland Security Research Center (NHSRC) is developing health-based Provisional Advisory Levels (PALs) for priority chemicals (including chemical warfare agents, pesticides, and toxic industrial chemicals) in air and drinking water. PALs are temporary values that will neither be promulgated, nor be formally issued as regulatory guidance.

Persistence and decontamination of surrogate radioisotopes in a model drinking water distribution system.

Contamination of a model drinking water system with surrogate radioisotopes was examined with respect to persistence on and decontamination of infrastructure surfaces. Cesium and cobalt chloride salts were used as surrogates for cesium-137 and cobalt-60. Studies were conducted in biofilm annular reactors containing heavily corroded iron surfaces formed under shear and constantly submerged in drinking water.

Laser-induced breakdown spectroscopy for the classification of unknown powders.

Laser-induced breakdown spectroscopy (LIBS) was used to discern between two biological agent surrogates (Bacillus atrophaeus and ovalbumin) and potential interferent compounds (mold spores, humic acid, house dust, and Arizona road dust). Multiple linear regression and neural network analysis models were constructed by using B. atrophaeus and ovalbumin spectra, and limits of detection were calculated.

Resampling permutation probability values for weighted kappa.

A permutation algorithm and associated FORTRAN program are provided for resampling weighted kappa. Program RWK provides the weighted kappa test statistic and the resampling one-sided upper-tail probability value.

Development and field testing of a mobile chlorine dioxide generation system for the decontamination of buildings contaminated with Bacillus anthracis.

The numerous buildings that became contaminated with Bacillus anthracis (the bacterium causing the disease anthrax) in 2001, and more recent B. anthracis - related events, point to the need to have effective decontamination technologies for buildings contaminated with biological threat agents. The U.

Human health risk assessment database, "the NHSRC toxicity value database": supporting the risk assessment process at US EPA's National Homeland Security Research Center.

The toxicity value database of the United States Environmental Protection Agency's (EPA) National Homeland Security Research Center has been in development since 2004. The toxicity value database includes a compilation of agent property, toxicity, dose-response, and health effects data for 96 agents: 84 chemical and radiological agents and 12 biotoxins. The database is populated with multiple toxicity benchmark values and agent property information from secondary sources, with web links to the secondary sources, where available.

Using ultrafiltration to concentrate and detect Bacillus anthracis, Bacillus atrophaeus subspecies globigii, and Cryptosporidium parvum in 100-liter water samples.

A strategy that uses ultrafiltration (UF) to concentrate microorganisms from water samples has been developed and tested. This strategy was tested using 100-liter water samples with volume reduction achieved through ultrafiltration and recycling the microorganisms of interest through a retentate vessel, rather than returning them to the sample container, where they might pose an incremental hazard to sample takers or the environment. Three protocols based on this strategy were tested.