Student Research: John Olson
The effects of chronic exposure to occupational noise are well documented in the scientific literature; however, exposure to non-occupational noise has received much less attention. Much of the existing research on non-occupational and leisure noise exposures has focused on infrequent but substantial exposures from activities such as concert and sporting events, the use of snowmobiles and off road vehicles, and recreational gun use.
In the current study the non-occupational noise exposures of 31 apprentice construction workers already participating in a longitudinal noise and hearing loss study were assessed through the use of data logging noise dosimetry and self-report activity diaries. Subjects were monitored over a consecutive four-day period and continuously reported their location, the perceived sound level, the number of people in their immediate area, and their activities and use of noisy equipment. The 1-minute interval dosimetry data was matched with the continuous diary data to construct a four-day exposure record. Of the 128,847 total minutes of data, 83.4% were below 70dBA, 11.8% were between 70dBA and 80dBA, 4.1% were between 80dBA and 90dBA, and only 0.6% exceeded 90dBA. Additional information regarding exposure levels and frequencies of leisure activity participation was collected from existing literature on non-occupational noise exposures and subjects' self-reported histories gathered as part of the longitudinal study. Using both the data collected and the supplemental data, an annual equivalent exposure level (Leq) was calculated to estimate the annual exposures resulting from non-occupational noise sources, and to compare this exposure to that resulting from occupational noise exposure. A sound pressure level of 70.6dBA was the lowest Leq calculated for a combination of the variables Regular Activity, Motorcycle, Machinery Use, Power Tools, and Loud Recreation. A sound pressure level of 87.1 dBA was the highest Leq calculated for a combination of the variables Regular activity, Motorcycle, and Power Tools. One-minute interval dosimetry data would suggest that non-occupational noise exposures do not normally contribute to a high annual noise dose when compared to occupational criteria; however, the potential of annual Leq data to exceed occupational limits for noise exposure was observed in exposure modeling when people participated in selected high-noise recreational activities.