Calculation of the dissolution

Following inhalation and deposition in the alveoli, the nanomaterial may dissolve and be removed. Dissolution may occur in the lung-lining fluid, or after phagocytosis in the alveolar macrophages. ConsExpo nano accounts for slow dissolution in the alveoli. Dissolution is modeled using a user-specified dissolution rate k (specified as a fraction of deposited mass dissolved per unit of time).

The deposited mass M_dep will change in time due to dissolution according to a linear kinetics decay as:

M_dep(t)=M_dep0 x e^-k×t

Dose metrics other than the mass will be evaluated by assuming that the primary nanomaterial will not change due to dissolution, but only the diameter of the deposited aerosol will shrink according to

d=d₀e^-k/3×t

The various dose metrics are then re-evaluated by first calculating how many nanoparticles will fit in the aerosol particle of reduced size, and then repeating the dose calculations  for the different dose metrics with adjusted total mass and aerosol size distribution.