Document Type


Date of Degree

Summer 2018

Degree Name

MS (Master of Science)

Degree In

Occupational and Environmental Health

First Advisor

Anthony, T Renee

First Committee Member

Nonnenmann, Matthew W

Second Committee Member

O'Shaughnessy, Patrick T


General noise regulations and guidelines protect workers against 8-hour time-weighted average noise exposures > 85-90 dBA that can cause health outcomes and noise induced hearing loss (NIHL), but the bus transportation industry has guidelines limiting lower noise exposures > 75-80 dBA to reduce safety hazards, including distraction and poor communication. These hazards can create dangerous driving conditions, especially for urban bus drivers, potentially causing a collision. Further research was necessary to characterize U.S. urban transit bus driver noise exposures to assess whether they exceeded 75, 80, 85, and 90 dBA, time-weighted, and to identify statistically significant noise exposure risk factors for this local transit system.

Time-weighted average noise exposures collected from the local transit system, a small urban bus system serving a university in Iowa City, showed the majority of drivers did not exceed 85 dBA due to short shift times, but these drivers may have been at a safety risk for distractions and poor communication due to loud environments > 75-80 dBA. The driver's AM/FM radio was a statistically significant risk factor (p = 0.004) affecting driver-shift TWA noise exposures. Projected noise exposure calculations showed that with bus driver shifts greater than or equal to 8 hours, the TWA noise exposures measured may exceed 85 dBA. Actual 8- hour time-weighted average noise exposures using sequential bus driver shifts did not exceed 90 dBA.


vii, 50 pages


Includes bibliographical references (pages 44-50).


Copyright © 2018 Austin Isamu Pierson