NIOSH 2003 Mar; :1-29
The National Institute for Occupational Safety and Health (NIOSH) received an employee request for a health hazard evaluation of the Fort Collins Police Services in Fort Collins, Colorado, in January 2002. The department was concerned about noise exposures and potential hearing damage from weapons training on their indoor and outdoor firing ranges. One specific concern was the Special Weapons And Tactics (SWAT) team of the Fort Collins Police Services and the type of customized hearing protection that they had recently purchased for the team members to use during training and deployment. To address these concerns, NIOSH conducted a temporary threshold shift (TTS) study of officers' hearing following weapons firing on a standard qualification course on the indoor and outdoor firing ranges. NIOSH investigators also used an acoustic mannequin head to measure noise levels produced by all weapons used by this department. This allowed for the measurement of noise levels when different hearing protection devices were placed on the mannequin, simulating the noise from weapons on protected and unprotected ears. The hearing test results showed almost no temporary loss of hearing among officers following weapons firing for the qualification course used in the evaluation. Also, the pre-exposure hearing tests revealed normal hearing patterns for the majority of the department, with only the oldest group of officers (> 45 years) showing a mild hearing loss pattern at the higher test frequencies. The noise measurements for the various weapons ranged from 159-169 decibels (dB) peak which is greater than a 140 dB peak exposure guideline from NIOSH. The peak reductions afforded by the ear plugs, ear muffs, and customized SWAT team hearing protectors were all in the 30 dB range. Double hearing protection (plugs plus muffs) added 15-20 db more of peak reduction. Based on the measurements and observations made during the evaluation, NIOSH investigators determined that a potential health hazard does exist for officers of the Fort Collins Police Services because the noise levels produced by their weapons are sufficient to put them at risk for occupational hearing loss. However, the hearing protection used by these officers does seem to offer protection as evidenced by the lack of TTS following a qualification course with pistols, shotguns, and rifles and by the normal hearing thresholds measured in nearly all of the officers.
Police-officers; Hearing; Hearing-conservation; Hearing-loss; Hearing-protection; Hearing-tests; Hearing-threshold; Noise-control; Noise-exposure; Noise-levels; Noise-measurement; Audiometry; Ear-protectors; Region-7; Hazard-Confirmed; Personal-protective-equipment; Emergency-responders
Field Studies; Hazard Evaluation and Technical Assistance
NTIS Accession No.
Research Tools and Approaches: Control Technology and Personal Protective Equipment
National Institute for Occupational Safety and Health