A statistical model of laboratory death rate measurements for airborne bacteria

Summary From 270 published laboratory airborne death rate measurements, two regression models relating the death rate constant for 15 bacterial species to aerosol age in the dark, Gram reaction, temperature, and an evaporation factor which is a function of RH and temperature were obtained. The independent variables accounted for 94% of the variation in the data for each of the two models. In both models the regression shows an increased survival rate with aerosol age accounting for approximately 90% of the total variation in the data. The remainder of the total variation was explained by temperature and RH (in interaction with the Gram reaction) in one model and by the evaporation function (in interaction with the Gram reaction) in the order model. Death rate data for gaseous atmospheric contamination, and light experiments were too few for building a regression model. In addition, these points were not well fit by the model indicating further research is needed to prepare realistic prediction models for airborne bacterial survival.