Randy L. Tubbs

Assessment of noise exposure for indoor and outdoor firing ranges.

The National Institute for Occupational Safety and Health (NIOSH) received an employee request for a health hazard evaluation of a Special Weapons Assault Team (SWAT) in January 2002. The department was concerned about noise exposures and potential hearing damage from weapons training on their indoor and outdoor firing ranges. NIOSH investigators conducted noise sampling with an acoustic mannequin head and 1/4 -inch microphone to characterize the noise exposures that officers might experience during small arms qualification and training when wearing a variety of hearing protection devices provided by the department. The peak sound pressure levels for the various weapons ranged from 156 to 170 decibels (dB SPL), which are greater than the recommended allowable 140 dB SPL exposure guideline from NIOSH. The earplugs, ear muffs, and customized SWAT team hearing protectors provided between 25 and 35 dB of peak reduction. Double hearing protection (plugs plus muffs) added 15–20 dB of peak reduction.

Occupational noise exposure and hearing loss in fire fighters assigned to Airport fire stations

The National Institute for Occupational Safety and Health (NIOSH) was requested to conduct a health hazard evaluation (HHE) at a large metropolitan fire department. The request concerned the hearing levels and noise exposures of fire fighters who were assigned to two fire stations serving the international airport. There was concern that these fire fighters were at a greater risk of accruing hearing loss than fire fighters located at other fire stations because of the addition of aircraft noise to their occupational noise exposures. The city also requested that NIOSH investigate other fire stations, not influenced by the airport, for noise exposures and hearing ability among a larger population of the fire fighters. NIOSH investigators conducted noise surveys at five fire stations and examined the hearing ability of 197 fire fighters. The noise surveys consisted of personal noise dosimetry on fire fighters assigned to the fire station for the entire 24-hr tour of duty over 2 consecutive days at each of the five stations. A NIOSH investigator accompanied the fire fighters on their vehicle to log response times and activities. The audiometric examinations were pure-tone, air conduction tests administered according to the Occupational Safety and Health Administrations (OSHAs) hearing conservation amendment. The noise dosimetry results revealed time-weighted averages (TWAs) that ranged from 60 to 82 dBA. However, the levels encountered during Code 3 responses (warning lights, sirens, and air horns) reached 109 dBA for a 1-min time period. The audiometric results showed that the average fire fighter exhibited a characteristic noise-induced permanent threshold shift.(ABSTRACT TRUNCATED AT 250 WORDS)

A task-based assessment of noise levels at a swine confinement

Abstract This study describes a task-based noise evaluation conducted at a community college that operated a small swine confinement for training and profit. Seven full-shift dosimeter samples and area noise data were collected during the evaluation. The time weighted average noise levels were all well below the Occupational Safety and Health Administrations (OSHA) Permissible Exposure Limit, but exceeded the National Institute for Occupational Safety and Healths Recommended Exposure Limit on three of seven occasions. The potential for high noise exposures is evidenced in the noise dose measured for specific activities such as power washing, ear clipping, and snout snaring. When the data were extrapolated to depict exposures where specific tasks were carried out over a full shift, tasks such as power washing and snout snaring would exceed the OSHA Action Level (AL). Employees who exceed the OSHA AL are required to be enrolled in a hearing conservation program.

Noise exposures during potato processing and manufacture of animal feed.

A noise exposure survey was conducted at an agricultural facility to evaluate noise exposures during potato processing and during the manufacture of alfalfa pellets. Of the 19 employees monitored, five reached or exceeded the National Institute for Occupational Safety and Health recommended exposure limit for occupational noise. Four of these employees were from the potato processing area, and one was from the alfalfa pellet-mill operation. Two of the five (bagger and pellet-mill operator) also exceeded the Occupational Safety and Health Administration action level. The facility has a well-managed hearing conservation program for employees in the potato processing area, but not in the alfalfa manufacturing area.