Particle deposition and exercise: further understanding beyond the intensity and duration of the task

This study aimed to quantify and compare the total and anatomical regions of fine particulate matter (PM_2.5) deposition in the human respiratory tract during endurance moderate exercise (EndME), endurance interval exercise (EndIE), and resistance exercise (RTE). A mathematical modeling-based analysis on anatomical and physiological characteristics of the human respiratory tract was conducted. The Monte Carlo method was performed to randomly generate different values of minute ventilation (ranging from 95% CI upper and lower) for simulated training sessions of 60 minutes for EndME and RTE, and 20 minutes for EndIE. Minute ventilation rate ranged from higher-to-lower in EndIE, EndME and RTE, respectively (p < 0.001). Compared to EndIE and RTE, during EndME there was greater lung deposition for all lung regions, except for the mouth and bronchial tree (p < 0.001). Moreover, RTE presented less particles deposited in the respiratory tract (p < 0.001). Alternatively, when time-correction was considered, EndIE had the greatest deposition per minute and RTE had the lowest (p < 0.01). Based on our results, beyond the intensity and duration of the exercise, the characteristic of the task must be considered, since the RTE showed a lower amount of PM_2.5 deposition.