Spectral frequency and broadband noise analysis of the firefighter environment: Potential implications for cardiac health

Firefighters are well known to have elevated risk of adverse health outcomes across a wide range of diseases and injuries, including cancer, hearing loss, fatal cardiac events, post-traumatic stress disorder (PTSD), sleep disorders, and many other adverse outcomes. It has been speculated that the noise environment is a significant risk factor for several of these diseases. In particular, the impact of noise on cardiac outcomes has recently been identified. An environmental survey of noise that included spectral and broadband analysis was conducted across all 14 firehouses in a southeastern city in the United States as a first step to investigate firefighter health and noise. An octave band analyzer was utilized to take area measurements of noise, including background, alarms, sirens, tools, and other important miscellaneous noise sources throughout these 14 firehouses, including an assessment of noise impacts on sleeping quarters. Data showed that generally the noise surveyed was highly variable, and specific frequencies were associated with specific sources. Overall, many of the noise sources in the firehouse were above a broadband sound pressure level that has been associated with an elevated stress response that may be associated with adverse cardiac impacts. There were also a number of noise sources, such as cutting tools, that had very high noise levels that could increase the risk of hearing loss. The spectral analysis also showed there were a number of sources that emitted noise frequencies in a range associated with enhanced physiological sensitivity, especially with regard to stress responses.