AAAR 36th Annual Conference October 16 - October 20, 2017 Raleigh Convention Center Raleigh, North Carolina, USA
Abstract View
Numerical Investigation of Occupational-related Metal Aerosol Transmission and Deposition Patterns in a Virtual Human Respiratory System
YU FENG, Jun Wang, Ahmadreza Haghnegahdar, Marcio Bezerra, Oklahoma State University
Abstract Number: 524 Working Group: Aerosol Exposure
Abstract High-temperature metal fabrication activities such as welding and plasma cutting are commonly seen in workplaces. The pyroprocesses generate high concentrations of micro-/nano-sized particles loaded with toxic metals. Exposure to these metal aerosols poses serious adverse health effects such as respiratory diseases, neurological ailments and ultimately cancer to workers. Information on how the metal aerosol transmits and deposits in respiratory systems is critically needed to study these health effects and devise engineering controls. However, observations and measurements of respiratory deposition from human and animal studies are very restrictive regarding the limitations of flexibilities and resolutions. As an alternative, Computational Fluid-Particle Dynamics (CFPD) models are capable of providing high-resolution deposition data based on the natural laws of physics without invasive specimen collection. The objective of this study is to develop an experimentally validated CFPD model to predict the transport and deposition of the metal fume in a subject-specific human upper airway. Exposure conditions are determined by chemical and physical profiles of metal aerosols from the previous chamber and field studies on high-current stainless steel plasma arc cutting. Steady-state nasal inhalation conditions, i.e., 10 to 30 L/min are investigated in the parametric analyses. Results indicate that under the same inhalation flow rate, both the total and regional depositions in the nasal cavity increases when particle diameter decreases from 830 nm to 96 nm because of the enhanced Brownian motion effect. The particle deposition in the nasal cavity raised concern on anterograde movements of metals such as manganese to the brain through olfactory neurons. High inhalation flow rates lead to stronger inertial impaction and higher deposition. Moreover, the deposition mass of metal fume increases when the arc current increases from 20 to 50 A. Future work includes simulating transient breathing scenarios and intersubject variability studies.