Bacterial plume emanating from the air surrounding swine confinement operations

The objective of this study was to evaluate the levels of bacteria in the air plume immediately upwind at 25 m and downwind at locations 25 m, 50 m, 100 m, and 150 m from a confined animal feeding operation (CAFO). It was hypothesized that this would give insight into determining the maximal distance that bacterial organisms release from a CAFO could travel, which would be important in determining the optimal siting distance for future CAFO in relation to high population areas. The Andersen two-stage sampler was used to collect all of the bacterial samples from the animal confinement facilities. The data show a marked increase in bacterial CFUs/m³ inside the facility (18,132 CFU/m³ average) versus upwind (63 CFU/m³ average) and a steady downwind decrease out to approximately 150 m. Staphylococcus aureus was found to account for 76% of the organisms recovered. We conclude that the optimal placement of a swine CAFO would be at least 200 m from a residential area.