Darrick Dickerson

Project title: Identifying and Assessing Noise and Airborne Exposures in an Emergent Fabrication Program at a Large-Scale Aircraft Manufacturing Company

Degree: MS (Applied) | Program: Applied Occupational Hygiene (App OH) | Project type: Project
Completed in: 2016 | Faculty advisor: Martin A. Cohen



As advancements in aircraft technology move forward, emerging programs help make it possible to develop and fabricate new tools that are essential to the aircrafts’ manufacturing. No emerging program is without its potential risks, however, and it is important to investigate potential exposures to agents that may negatively affect the health and safety of workers. In this study, noise and airborne agents were identified as having the potential to present negative health effects to workers doing several different processes in an emergent fabrication program at a large aircraft manufacturing company. The differences between each process paved the way for a variety of potential exposures that were investigated to determine their risk. Noise dosimeters were used to monitor personal and area sound levels during several different processes to gauge the potential for occupational noise-induced hearing loss. Several processes were sampled for airborne exposures including oil mists, metallic dusts, NO/NO2, ozone, total dusts, carbon fibers, nitric acid, and chromic acid. Based on the dosimeter results, shim milling, thermal spraying, and shot peening were all identified as being high noise operations. Shim milling had at least one TWA reading above the 85 dBA criterion needed for admittance to a Hearing Conservation Program. Thermal spraying and shim milling had several peak noise readings at or above 115 dBA indicating that the process is high noise, signage must be posted, and hearing protection is required when doing the processes. Most exposures to airborne agents were below regulatory exposure limits. Only NO2 had a concentration that exceeded the short-term exposure limit. All processes that were recognized as having high noise operations had workers wearing earplugs as PPE. Localized and shop ventilation were used to reduce exposures to airborne contaminants in processes that involved inhalation exposures. Further sampling is required to draw conclusive evidence of exposure levels during typical 8-hour shifts of workers. Current PPE and engineering controls should continue to be used to reduce the risk of future exposures.