Field Tests Culminate 4 Years of Bioagent Studies

An EPA contractor sprays a building exterior to show how to clean it if it was contaminated with a biological agent such as the anthrax-causing bacteria Bacillus anthracis. Efficiently decontaminating surfaces contaminated with pathogenic organisms is critical for quick recovery and return to normal operations.

The Science and Technology Directorate (S&T) collaborated for four years with top scientists at the U.S. Environmental Protection Agency (EPA) and the U.S. Coast Guard (USCG) to ensure first responders and USCG personnel are properly equipped and trained to respond to a variety of biohazard emergencies—from naturally occurring disease outbreaks to an accidental or intentional release of a bioagent. The joint effort, called Analysis for Coastal Operational Resiliency, or AnCOR, included several targeted field assessments over the course of the project studying everything from vessel decontamination to how pathogens are transported by rain.

“The focus of AnCOR is on preparedness and planning to respond to biological-related emergencies,” said S&T Program Manager Dr. Don Bansleben. “We test strategies, methods and technologies for cleaning up as quickly as possible the affected areas so USCG can resume its crucial work safeguarding our coastlines and waterways.” 

S&T and its partners convened in Virginia throughout May 2022 for the culminating AnCOR event Wide Area Demonstration (WAD). This outdoor event simulated a response to an anthrax incident and examined lab-tested response procedures to help USCG respond to future biohazard incidents.

The goal of WAD was to test field technologies and methodologies for use by responders. “Confirming what works in the laboratory also works in the field before an actual incident is critical to saving time and reducing clean-up costs,” said Bansleben. The team followed steps that embodied an actual biological response: inoculation (‘contamination’) of different surfaces with a benign surrogate for the anthrax-causing bacteria; sampling before and after decontamination; data management of the hundreds of samples; decontamination of inoculated areas; and waste management of used and contaminated materials. USCG National Strike Force members participated in pre- and post-decontamination sampling and provided valuable feedback. 

“This project and demonstration helped us learn the procedures we’ll need to follow and will prepare us to respond to biological incidents involving anthrax and other pathogens,” said USCG industrial hygienist Emile Benard.

The photos below offer a peek at the intricacies of each stage of the AnCOR WAD testing. Findings will be released jointly by S&T and EPA later in 2022.


Inoculation, particularly for the purpose of a simulated biological incident like this, means spreading a precise amount of a microorganism on a surface that will be later decontaminated. For WAD, EPA researchers mixed water with the benign spores of Bacillus atrophaeus var. globigii, a close relative of the anthrax-causing bacteria, and sprayed the mixture on various outdoor surfaces that could be found on a typical USCG base, like concrete, asphalt, wood decks, building facades, gravel and grass.

EPA’s Dr. Shannon Serre (right) and Dr. Worth Calfee spray a field with benign spores of anthrax-like bacteria. “AnCOR helps agencies work together to solve a common problem and will help develop guidance useful for other federal agencies as well,” said Serre, EPA chemical engineer.

Sampling before and after decontamination

“In order to accurately assess the decontamination performance, we need to know what the difference is before and after decontamination,” said Dr. Worth Calfee, EPA research microbiologist. 

The team collected baseline samples from the various surfaces; after contamination, USCG responders took additional samples and tested the surrounding air for any airborne spores.

USCG participants practice different sampling techniques. Left: Taking samples from a concrete sidewalk using sponge-sticks. Center: Taking samples by trimming grass. Right: Placing tree/shrub leaves and gravel in plastic sample containers.

In addition to traditional sampling with sponge-sticks, S&T funded the development of the Activity-Based Aggressive-Air Contained Sampling System (AACeSS), a novel mechanical device that can be used to collect air samples over multiple types of surfaces. 

“AACeSS is an important advancement for sampling wide areas and reducing the number of samples taken using traditional methods, typically taken from 10-inch by 10-inch square areas,” said Bansleben. “It can potentially speed the process of characterization of a biological agent event—both before and after decontamination—and thus save time and money to analyze and characterize large geographic areas.” 

“AACeSS was a solution to the problem for sampling a wide area for bioagents, and we wanted to see if spores could get resuspended off the surface yet contained in the sampler, captured on the filters and analyzed,” said EPA industrial hygienist John Archer, who researches sampling and characterization of bioaerosols and designed AACeSS. “AACeSS gives you a better idea of what could get into the air that you could breathe in.”

Once captured, the samples were sent for analysis to EPA’s Research Triangle Park Microbiology laboratory. Pre- and post-decontamination sample collection and analysis helps ensure the affected site is successfully decontaminated.

Dr. Adam Hook, contractor for EPA, and Dr. Lukas Oudejans of EPA operate a prototype AACeSS sampling machine, which collects air samples of resuspended particles from multiple types of surfaces over hundreds of square feet. AACeSS commercial off-the-shelf components include a leaf blower to make spores airborne, a negative air machine to suck up the spores, a filter plate to collect the spores, and a final HEPA filter to clean the air coming out. This picture was taken during the WAD demonstration of the equipment and did not include the use of any bioagents.

Data management

Because sampling is a critical step of the process that helps inform the proper course of action, keeping track of the hundreds of specimens is key. They are cataloged with additional details such as location, date, time, and sample type. 

“To facilitate the sample tracking, data management has helped communicate and document the samples by automating this otherwise very arduous process,” said EPA geographer Timothy Boe. “Interestingly, when you arrive at your sampling location and scan in the sampling bag, the software marries the bag to that specific location.”

As team members prepare to take samples, a data manager holds a GPS pole and readies a tablet to scan and record each sample.

Once all the data are collected and analyzed, the data management team can estimate the extent of contamination using statistical methods that calculate the location and potential movement of contamination. “Statistics can also determine how reliable are the results we’ve generated,” said Boe.

A screenshot shows a map of the WAD study area and completed pre-decontamination samples. Samples appear on the map once each team’s data manager submits a completed sample.


“Without decontamination, the Coast Guard cannot reoccupy and reuse its facilities,” said EPA research physical scientist Dr. Lukas Oudejans. “We have done laboratory studies to determine the chemicals and technologies suitable to decontaminate surfaces and materials found at a Coast Guard station.”  

Different surfaces require different types of spraying equipment and decontaminants. For wide areas, various municipal or agricultural equipment could be suitable, like boom sprayers for roads and lawns and pressure sprayers for tall buildings, foliage and trees. For hard surfaces, EPA researchers chose the strong bleaching agent calcium hypochlorite; for vegetation, they selected peroxyacetic acid solution to reduce potential harmful effects to plants as it later degrades into vinegar and water. 

A truck sprays decontamination liquid using agricultural equipment like a boom sprayer. The large container can hold up to 500 gallons of decontaminant. Equipment size can be scaled up or down to meet the needs of the incident.
EPA contractors decontaminate vertical walls wearing personal protective equipment to prevent inhalation from both the spores and the chemicals being sprayed.

Waste management

As soon as a biohazard incident happens, waste starts piling up, even before first responders come to the scene. “We tested how contaminated materials can be best disinfected and disposed of,” said EPA chemical engineer Dr. Paul Lemieux.

For efficient on-site decontamination of both heavy and buoyant waste, EPA collaborated with North Carolina State University to design waste bags made of innovative semi-permeable, non-woven material that keeps the spores inside the bag while allowing gas and moisture to penetrate contents in the bag.

“You can fumigate bags full of contaminated waste on-site with chlorine dioxide or methyl bromide without opening the bags, because if you open them, you run the risk of contaminating everything including workers not wearing proper protection,” said Lemieux. “Successfully and safely decontaminating waste could be a game-changer for properly disposing of cleaned materials.”

Left: Rope, clothing, personal protective equipment and foam are examples of used USCG materials in need of decontamination. Right: EPA waste management experts Dr. Christy Tomlinson (right) and Dr. Paul Lemieux (far left) show WAD participants a semi-permeable bag to contain contaminated waste. When full, the bag will be fumigated to decontaminate its contents. Pores in the novel bag material are too small for spores to escape.

The path forward for AnCOR

“In the long-term, the lessons we learn from AnCOR and WAD would be applicable to most biohazard incidents,” said William Pharis, assistant director of S&T’s Office of Mission and Capability Support, who also attended the May testing. “By working together, we leverage the joint S&T-EPA team’s strengths—resources, program management expertise, scientific and technological expertise, but most importantly passionate and dedicated people.”

“We’re very fortunate to have a long-term partnership with S&T,” said Dr. Gregory Sayles, director of EPA’s Center for Environmental Solutions and Emergency Response. “EPA and S&T bring different strengths: S&T prepares the nation for emergencies, and EPA prepares the nation for environmental disasters. Together we’re building strong relationships to respond to emergencies.”

After WAD, S&T and EPA will prepare a procedure manual and maintenance cards that USCG can leverage to return quickly to operational capacity should a real outdoor, urban-area biohazard incident occur. 

“We are taking advantage of the capabilities and the experts in different parts of the government to find solutions to very complex problems that the government must solve while wisely using taxpayers’ dollars,” said Bansleben.

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