processes-at different conditions. Data from a different experimental approach might not

encounter this uncertainty, and the assay is only a surrogate for the goal of the technology-

enhancing respiratory protection against bioaerosol transmission of pathogens. Both the medium

in the impinger and the protein gel have elements in common with respiratory mucosa, and for a

person wearing individual protective gear, the time of transit from filter to mucosal surface is

similar. However, competition by water and by proteins at the site of impaction might or might

not behave the same as in the in vitro systems tested to date. So, the ultimate measure of

enhancement of protection by surface-bound iodine-or any other reactive surface on filter

fibers-will require data from animal exposure studies.