| This dissertation investigated workers' exposures to synthetic textile (ST) dust during the finishing of polyester fabric and identified the characteristics of the dust potentially related to the workers' respiratory health concerns. The dissertation has three parts: (1) the development of air sampling and analytic methods to evaluate regional ST dust lung deposition, (2) the determination of the chemical and physical composition of the ST dust, and (3) the modeling of workplace exposure determinants to identify effective engineering controls.; The first part of this research compared the ST dust exposure measures of mass concentration, fiber number concentration, and particle number concentration among three air sampling devices: the closed-face cassette (CF), inhalable IOM, and TSI Respicon Virtual Impactor. The Respicon collected more of the particles and fibers of the ST dust than the IOM and CF. The Respicon sampler is also designed to separate the inhalable mass concentration into four size ranges (respirable, tracheobronchial, thoracic, and extra thoracic).; The second part of this research involved determining the composition of the ST dust. Physically, the ST dust was a mixture of particles and fibers in size ranges that were capable of depositing anywhere in the lung, especially the respirable region of the lung. Chemically, the ST dust particles were determined to be plastics, minerals, chemicals and chemical salts, rust and metals, soots, dyes, and organic debris. Also, 50% of the inhalable particles contained at least one element that had the potential to induce adverse respiratory effects.; The final part of the research focused on the generation and control of the ST dust in the finishing department of a ST mill. An inverse relationship was found between the voltage levels measured from fabrics as they exited each of the five finishing machines (tenter, perch, SAN, shear, and napper) and the amount of ST dust produced at each machine. In order to have the greatest effect in controlling the ST dust, engineering controls should be implemented to reduce the electrostatic charge of the fabric after it exits the shear machine and remove the dust from the fabric before it enters the tenter machine. |
