Evaluation of the Andersen viable impactor for single stage sampling.

A modified use of the 6-stage Andersen viable sampler for single stage sampling is described. Although size distribution data are not obtainable with such a sampler, it has utility as a simple and convenient method for estimating the total concentration of viable airborne microorganisms. The method was compared in the field to the standard Andersen sampler and a previously described method for single plate sampling. Over a wide range of airborne fungal concentrations (10-3000 CFU/m3), the modified sampler was found to be superior to the previous method and comparable to the standard Andersen sampler (in terms of both precision and accuracy), for estimating total airborne fungal concentration.