Theoretical deposition of fungal aerosol particles in the human respiratory tract

Total and lobar depositions of fungal particles in the human lung were calculated for the workers in a cotton spin factory using an updated version of the Monte Carlo transport and deposition code IDEAL. The study is based on nasal breathing under light exercises activity with a standard functional residual capacity (FRC) of 3300 ml, tidal volume (VT) of 1250 ml and breathing frequency (f) of 20 min−1. The present calculation is based on our previous measurements of the size distribution of fungal particles in the cotton spin factory using six-stage Andersen impactor as a viable sampler. The measurements were carried out in the two main working departments: carding department (Dept1) as a model for high dust concentration area and spinning department (Dept2) as a model for low dust concentration area. It was found that the total deposition of fungal particles is higher in the carding and blowing department (Dept1) than that in the spinning department (Dept2). For lobar deposition, it was found that the deposition of Aspergillus niger and Penicillium has the highest deposition in the RL and LL lobes. These predictions show two distinct deposition maxima at the bronchial and the acinar regions with the highest deposition being in the acinar region. In all cases, the deposition reaches its maximum at generation 12 in the bronchial region and at generation 22 in the acinar region. The results reveal a positive relationship between the deposition of biological particles and some respiratory diseases.