## 1 Introduction  
Discharge of a radiological dispersal device (RDD) or an accidental radiological release may cause contamination over a wide area. During response and recovery, emergency responders, recovery workers, and the general public may be exposed to radioactivity due to direct contact and inhalation. Direct contact results from \"hands-on\" activities with contaminated material or exposure to unshielded radiation sources. Inhalation exposure could originate from dust generated by the release incident or during demolition or decontamination work [1], as well as from the resuspension of such dust during work activities. The risk of tracking contamination via vehicle or foot traffic is of significant concern. Tracking can lead to contaminant spread which enlarges the contaminated area, potentially increasing the time and expense of decontamination efforts. Control of the contamination source area to prevent resuspension and tracking could both reduce radioactivity exposure and reduce the spread of contamination. Hence, there is a need for technologies and methodologies to limit exposure, reduce resuspension, and limit the tracking of radioactive materials. Such technologies have been widely investigated for nonradioactive materials due to the importance of controlling urban particulate matter and its associated human health effects. These technologies broadly fall into two categories: physical removal and stabilization [1; 2; 3; 4]. Physical removal approaches include sweeping, washing, wiping, and vacuuming. Stabilization technologies prevent particles from spreading by resuspension or tracking, and such technologies are routinely used for dust control in industries such as road construction, and at mining sites. Technologies for preventing secondary transport of soluble and particulate radiological contamination from roadways, roadside vegetation, and adjacent soils have recently been reviewed by Saito [5]. Although the focus of the review was preventing resuspension associated with decontamination activities, not necessarily resuspension arising directly from vehicle and foot traffic, it suggests that widely available and easily applicable stabilization technologies have the potential to minimize worker exposure by reducing the spread of contamination. These technologies may also minimize the resuspension of radioactive particles from surfaces, thus reducing the time and resources needed for additional decontamination operations [5]. Technologies for minimizing resuspension are an active research area because of keen interest in controlling dust and other particulate matter from anthropogenic sources due to its potential impact on human health [3; 6; 7; 8; 9; 10; 11; 12]. In a previous study, the U.S. Environmental Protection Agency (EPA) assembled stakeholders with expertise in radiological stabilization and performed a downselection exercise to prioritize experimental testing of stabilization technologies (e.g., water, fire retardants, gels, foams, and clays) based on literature searches and the personal experience of the stakeholders [13]. Twenty-four technologies were identified, and, based on stakeholder ranking, a fire retardant (Phos-Chek MVP-F) and two dust suppression technologies (Soil\({}_{2}\)O and CaCl\({}_{2}\)) were downselected to evaluate the efficacy of particle stabilization during vehicle and foot traffic. This evaluation determined that cesium (Cs)-137 quantitatively bound to both Phos-Chek MVP-F and Soil\({}_{2}\)O, while CaCl\({}_{2}\) application increased sorption of aqueous Cs-137 onto the surface matrix, Arizona road dust. During driving activities, the transfer of particles from treated surfaces was least for Phos-Chek MVP-F fire retardant, followed by Soil\({}_{2}\)O. The transfer of particles was greatest for surfaces treated with CaCl\({}_{2}\).