WEI-CHUNG SU, Yi Chen, University of Texas Health Science Center at Houston
Abstract Number: 85 Working Group: Aerosol Exposure
Abstract Ultrafine particles (UFPs) in the workplace has been an important occupational health concern. Many workplace operational processes such as welding and high-speed grinding are known to generate UFPs in the workplace. The inhalation and the consequent deposition of UFPs in the worker’s lower airways could lead to adverse health effects. Therefore, investigating the deposition of UFPs in the human respiratory tract is extremely vital from the viewpoint of occupational health. The experiment of UFP respiratory deposition can provide important information on the fate of inhaled UFPs in the lung airways and can be used to estimate the UFP inhalation dosimetry. However, due to the limitations of the current experimental method, it is extremely difficult to conduct UFP deposition experiments in human airway replicas. As a result, the nature of UFP deposition in the human airways remains not well understood. To fill this gap, a novel experimental method was developed in this study to measure the UFP respiratory deposition. A hollow human tracheobronchial airway replica down to the 10th lung generation was made by a 3D printer (with a total of 1,024 lung tube outlets). The tracheobronchial airway replica along with a human oral airway replica were used to construct a simplified human airway system. With the assistance of two GRIMM SMPS+C systems connected at the inlet and outlet of the simplified human airway system, the deposition of UFP in the airway replica could be correctly estimated according to the difference of the UFP concentrations measured. The performance evaluation and the deposition results acquired in this study showed that UFP respiratory deposition data could be directly and systematically measured for the 1st to 10th lung generations by the novel experimental method developed. The deposition data acquired can be used for developing worker UFP exposure index and also for validating relevant numerical simulation data.