Aerosol dissemination of veterinary pathogenic and human opportunistic thermophilic and thermotolerant fungi from thermal effluents of nuclear production reactors

Abstract

The extent to which veterinary pathogenic and human opportunistic species of thermophilic and thermotolerant fungi disseminate in aerosols from heated effluents of nuclear production reactors of the Savannah River Plant (SRP), South Carolina, has been measured. Aerosol samples were taken at 140 sites, from directly over thermal effluents to more than 100 kilometers from the SRP boundary. Sampling methods included settle plates (134 sites, 1, 103 plates for a total of 2, 805 hrs.), liquid impingement (78 sites, 1 cubic meter each), filtration (79 sites, 1 cubic meter each), and a particle sizing cascade impactor (Andersen Sampler) (17 sites, 1 cubic meter each). Soils, foams, and microbial mats from thermal effluents (a total of 191 samples), and vegetation (560 samples) were sampled to study distribution of particular species. Sampling was done under a variety of conditions: hot weather and cold, wet and dry, day and night, windy and calm, reactor(s) operating and not, disturbed vegetation and undisturbed. At 102 of the aerosol sampling sites, sophisticated meterological analyses were used to allow sampling of air in the plume which originated from thermal effluents. Soil, foam, microbial mat, vegetation, and aerosol samples were quantitatively plated for detection of viable units; filters were halved and then both plated and observed microscopically.

Significant dissemination of thermophilic and thermotolerant fungi from thermal effluents was not detected. Thermophilic and thermotolerant fungi were widely distributed in soil, air, and on vegetation. Dactylaria gallopava, the indicator species and dominant fungus in microbial mats lining SRP thermal effluents and the cause of epidemic fatal phaeohyphomycosis in flocks of turkeys and chickens in South Carolina, Georgia, and elsewhere, was isolated from air at a maximum of 50 meters from effluents (8 viable units per cubic meter of air in the plume of an effluent during a strong wind).