Modelling on NaCl and H2SO4 aerosol rehydration and retention in respiratory systems

The effect of particle rehydration on the retention of inhaled soluble aerosols in the respiratory systems is reviewed, and results obtained with four different models are discussed. Results have indicated that only relative humidity plays an active role to influence aerosol growth rate. At any constant ambient temperature all four models previously studied exhibit the same trend for aerosol growth. Since relative humidity in the respiratory tract is believed to be within the range of 96-99.5%, it is reasonable to expect the four models to display similar retention patterns once the aerosol size has reached its terminal diameter prior to entering the trachea. Due to the Kelvin and hysteresis effects, variation in NaCl aerosol size is different from that of H₂SO₄ droplets. A time-dependent retention model is used to predict aerosol retention and to compare the effects due to inhaled soluble NaCl versus H₂SO₄ aerosols