(480c) Towards Understanding Fly Ash Transport and Deposition in the Human Respiratory System: Effects of Physiological Conditions and Fly Ash Properties

Fly ash is a common solid residue of incineration plants and poses a great environmental concern because of its toxicity upon inhalation exposure. The inhalation health impacts of fly ash is closely related to its transport and deposition in the human respiratory system which warrants significant research for health guideline setting and inhalation exposure protection. We carried out a series of fly ash transport and deposition experiments in a bifurcation airway model by combining optical aerosol sampling analysis and high-speed photography technique. Five types of coal fly ash samples of different morphologies were tested and their respiratory deposition and transport processes were compared. The deposition efficiencies were calculated and relevant transport dynamics mechanisms were discussed. The influences of physiological conditions such as breathing rate, duration, and orientation [horizontal (lying-down case) and vertical (standing case)] and fly ash physical properties (size, morphology, and specific surface area) were investigated. The fluid mechanisms governing the transport dynamics and deposition patterns of fly ash particles were explored. The study serve as a basis for setting health guidelines and recommending personal respiratory protective equipment for fly ash handlers.