Projects - Noise exposure
Noise Exposures in Electrical Trades
Noise dosimetry was used to assess the exposure levels of electricians working for a major electrical subcontractor. Five sites that used four construction methods were visited. Electricians documented activity and environmental data throughout their work shifts, resulting in an activity/exposure record for each of the 174 samples collected. More than 24% of the 174 full-shift exposure samples exceeded the current Washington state (WISHA) permissible exposure level (PEL) of 85 dBA; 5.2% exceeded the federal OSHA PEL of 90 dBA. When measured with a NIOSH exposure metric, 67.8% exceeded 85 dBA and 27% exceeded 90 dBA. The WISHA maximum instantaneous exposure level of 140 dBA was exceeded in 99.4% of samples. Pneumatic power tools, power-actuated tools, and the hand hammer resulted in the highest exposures among tools used by electricians. Results of the study indicate electricians are at risk of developing noise-induced hearing loss, their exposures are affected by adjacent activity, and engineering controls can reduce exposure levels.
Seixas NS, Ren K, Neitzel R, Camp J, Yost M. Noise exposure among construction electricians. AIHAJ. 2001 Sep-Oct;62(5):615-21.>
Assessment of Occupational Noise Exposures in Four Construction Trades
In this study, noise exposure samples were collected from construction workers employed by a general contracting company in four construction trades: carpenters, laborers, ironworkers, and operating engineers. Workers completed a questionnaire detailing the timing, number of tasks performed, and tools used throughout the day. Trade was a poor predictor of noise exposure; construction method, stage of construction, and the work tasks and tools used were found to be better predictors. The mean OSHA time-weighted average (TWA) for 338 samples was 82.8 dBA while the mean NIOSH/ISO TWA for 174 samples was 89.7 dBA. Forty percent of OSHA TWAs exceeded 85 dBA, and 13% exceeded 90 dBA, the OSHA permissible exposure level. The highest exposure levels were those involving pneumatically operated tools and heavy equipment. An internal validation sub-study indicated excellent agreement between worker-reported and researcher-documented tasks and tools.
Neitzel R, Seixas NS, Camp J, Yost M. An assessment of occupational noise exposures in four construction trades. Am Ind Hyg Assoc J. 1999 Nov-Dec;60(6):807-17.
Vibration and Noise Exposure Levels in the Forestry Industry
Workers in the forestry industry are exposed to a number of sources of hand-arm and whole-body vibration from a variety of hand tools and heavy equipment. This problem, which has received little attention in the US, has been associated with negative health effects, such as Hand-Arm Vibration Syndrome, in other countries. This pilot study took 177 hand-arm and whole-body vibration measurements of forestry workers using a variety of vibration-producing equipment; 46 TWA noise exposure measurements were taken simultaneously to estimate the degree to which vibration exposure levels may be predicted by noise exposure levels. Forestry workers in this study were exposed to substantial vibration and noise exposures. The task-based exposure assessment approach used in this study, combined with multiple regression modeling, will help identify work characteristics that give rise to elevated exposure levels.
Occupational Hearing Loss
This study, funded by NIOSH, measures noise levels and examines hearing protection programs at 90 workplaces in Washington state in an effort to identify ways to help businesses reduce the risk of employee hearing loss. The study includes collecting noise dosimetry information, interviewing employers and employees, and analyzing audiometry. To date, six industries have been approached to participate: sawmills, road construction, sheet metal manufacturing, machine shops, fruit and vegetable processors, and pulp and paper companies. About half the targeted companies have agreed to participate in the study, and almost 500 employees have been monitored or interviewed.
FRCG Quarry Sampling Summary Report
The FIELD GROUP developed a summary report of sampling results for noise and silica at 10 open surface mines. Samples were collected across all seasons for a year. Employees who had a potential for exposure to noise or silica dust were monitored. For all eight jobs monitored, the mean 8-hour noise exposure exceeded 85 dBA. The exposure of only groundsmen exceeded 90 dBA, although crusher mechanics had exposures approaching this limit. For silica exposure, only groundsmen had a mean exposure at the silica permissible exposure level of 10 mg/m3. Recommended controls included fitting heavy equipment with cabs and air conditioning, fitting generators with supply and exhaust air mufflers, upgrading conveyor belts to reduce the need for belt cleaning by a groundsman, soundproofing the crusher operator's booth, and shifting groundsmen's work schedules to reduce their time near operating equipment.