Comparison of a personal sampling technique with a Six-Stage Andersen Cascade Impactor for viable bacterial aerosols in a mushroom plant

A personal sampling method employing the use of an MSA sampling pump and Gelman 0.8 micron membrane filter was compared with a Six Stage Andersen Cascade Impactor for sampling viable bacterial aerosols in a mushroom plant. Four separate sets of samples were taken. Included within each set of samples were eleven membrane filter samples taken simultaneously for ten minutes and two separate sixty second Andersen Impactor samples taken within the ten minute sampling period. All samples were obtained at one location. Microbial concentrations from the Gelman filters were determined by first placing the filter in a nutrient broth and suspending the collected organisms within the broth. The suspension was then plated onto a nutrient agar medium and the resulting colonies counted. The microbial concentrations from the Gelman filters were found to be quite variable within each sample set and were significantly different from the concentrations obtained with the Andersen Microbial Sampler. A stong linear relationship was present when the mean values from the data groups for the two sampling methods were compared. When comparing individual personal sampling method values with the mean values from the Andersen Microbial Sampler, a moderate to good linear relationship was found.