Age-Specific Deposition of Indoor Particulate Matter in the Human Respiratory Tract

Exposure to indoor particulate matter (PM) plays a significant role in human respiratory problems resulting in multiple adverse health outcomes. PM having an aerodynamic diameter ≤10 µm, enters the human airways due to its smaller size and gets deposited in different parts of the human lungs. In the present communication, we measured real-time size segregated particulate matter mass concentrations in residential houses’ indoor environments in Pune's urban locations by Grimm aerosols spectrometer during the day hours (i.e.10 a.m–5 p.m.) in the month of July 2021. Average concentrations of indoor PM10, PM2.5, and PM1 were found to be 60.7 ± 30.6, 37.3 ± 24.6, and 23.2 ± 19.7 µg m−3, respectively. Particle deposition in human airways diversely depends on the airway’s geometric structure. Thus, the evaluation of respiratory deposition doses (RDDs) in the head airway (HD), tracheobronchial (TB), and alveolar (AL) regions of PM (i.e., PM10, PM2.5, and PM1) were estimated by using the human respiratory tract model (ICRP 1994) for different age groups like infants, children, adults, and elderly in residential premises. For the calculation of RDDs, tidal volume and breathing frequency of lungs for different age groups were considered. Total respiratory deposition of PM10 was frequently higher than PM2.5 and PM1 over all age groups. However, among all, the elderly people experienced the highest total PM10, PM2.5, and PM1 deposition (46 × 10–2, 29 × 10–2, and 9 × 10–2 µg min−1), followed by adults, children, and infants. Results derived from tracheal regional deposition exhibited the dominance of PM10, PM2.5, and PM1 in HD, TB, and AL regions, respectively.