How many samples are necessary to find a mold problem?
The proper number and location of air samples is often a matter of debate and depends on the questions to be answered, strength of desired conclusions and on cost. Mold levels vary greatly with season, temperature, humidity and time of day. This variability requires that multiple samples be collected at each location to be sure the observed difference is real and not just due to chance. A report recently released by the National Academy of Sciences addresses the difficulties associated with sampling. “Thus, because only sparse data are available on variation of exposure to biologic agents in the home environment, it is not possible to recommend how many samples should be taken to produce an accurate assessment of the risk-relevant exposure. However, there is a strong suggestion that airborne concentrations are characterized by high variability over time, an indication that one sample per home is unlikely to be sufficient even when acute health effects are being considered, because vari
