Development of an Aggressive-Air Activity-based Air Sampling System for Collection of Bioaerosols in Outdoor Areas

JOHN ARCHER, M. Worth Calfee, Adam Hook, Robert Yaga, William Schoppman, Jerome Gilberry, US EPA

     Abstract Number: 509
     Working Group: Bioaerosols

Abstract
A wide-area intentional release of a biological agent such as Bacillus anthracis would require very complex and potentially daunting remediation efforts. There has been significant progress made in developing capabilities and preparedness to respond to indoor biological contamination incidents, particularly for relatively contained ones (e.g., single facilities). However, capabilities and an operational strategy for cleaning up the outdoor environment do not exist for a biological agent incident, and as such, represent a major preparedness gap. Characterization, determination of the extent of contamination, and clearance of remediated areas using current surface sampling methods may require unrealistic numbers of samples to be collected over a long time. EPA researchers have developed an aggressive air sampling system for contaminated outdoor surfaces following a wide-area release to be used in conjunction with surface sampling to cover larger areas in a shorter time period.

AACeSS (Activity-Based Aggressive-Air Contained Sampling System) is an innovative air sampling system developed by EPA for use in bioaerosol sampling following a wide area biological release. Initial research efforts evaluated a tent-based system, but the current version of AACeSS is a mobile cart-based sampling system used to collect bioaerosol samples from multiple outdoor surfaces, including grass, gravel, asphalt and concrete. This sampling cart uses a leaf blower as a means of disturbing the surface with aggressive air and captures resuspended particles through a connected negative air machine (NAM) outfitted with multiple filters. These air samples combined with personal activity-based sampling conducted with SKC Button Aerosol Samplers in the breathing zone of operators provide a measure of spores that could potentially be resuspended from surfaces and pose an inhalation hazard. Recoveries of spores in lab and field tests with AACeSS demonstrate its effectiveness in an outdoor environment. An overview of AACeSS development will be presented along with bioaerosol collection results from lab and field tests.