Hearing Loss, Noise Exposures, and Hearing Protection Use in Midwestern Farmers: A Preliminary analysis Josie J. Ehlers, MPH Environmental, Agricultural, and Occupational Health Dept. College of Public Health, University of Nebraska Medical Center June 27, 2016

Hazardous noise in agriculture High prevalence of hearing loss –Second highest rate out of 25 different industries (Tak & Calvert, 2008) –Estimated 25% young farmers and 50% older farmers have hearing loss (Rein, 1992) –Most will have some evidence of hearing loss by age 30 (Rein, 1992) Image Source: Indiana Grain LLC, 2008

Objectives Evaluate two-years of data from a 4-year randomized control study −A point-sourced intervention designed to increase hearing protection use. Assess the typical noise exposures on the farm Evaluate the characteristics of hearing loss among farmers Evaluate the attitudes and beliefs regarding hearing loss and hearing protection Evaluate changes over time

Methods Study Design –Visits at baseline (year one) and at year two The following measurements were collected:  Personal noise dosimetry  Audiometric testing  Hearing protection device perception (HPDP) questionnaire Study Population –Fifty-two farms were recruited and randomized Control farms (n=26)  36 farmers Intervention farms (n=26)  51 farmers

Methods Personal Noise Dosimetry Measurements −Larson Davis dosimeter, Model 706 Automatically computed into OSHA and NIOSH standards Image Source: The Modal Shop, Inc., 2015

Methods Audiometric Testing –Conducted annually on each farm –Administered by occupational hearing conservationist −Stratified into categories of hearing loss at each frequency per recommendations by NIOSH

Methods Hearing Protection Device Perception (HPDP) Questionnaire –Gauged farmers’ attitudes and beliefs about hearing loss and hearing protection –Evaluated Perceived barriers to preventive actions Self-efficacy Social norms Perceived susceptibility to hearing loss Perceived severity of consequences of hearing loss Behavioral intentions

Results Personal Noise Dosimetry Figure 1 – Percentage of farmers that exceeded exposure standards

Results Substantial amount of variability −NIOSH’s REL More Conservative + More Accurate = More Protective Researchers suggests that protective measures should be taken under all circumstances (Rabinowitz, et. al, 2013) −Even moderate noise exposures over an extended period of time could cause permanent hearing loss

Figure 2 – Frequency distribution of hearing loss in the left ear for all farmers at year one. Figure 3 – Frequency distribution of hearing loss in the right ear for all farmers at year one. Results Audiometric Testing

Results Audiometric Testing −Most considerable hearing loss was observed between 4000 Hz and 6000 Hz Typically associated with high frequency noise exposures and often considered noise-induced hearing loss (Depczynski, Challinor, & Fragar, 2011) Other factors could predict individual susceptibility −Left ears tended to have more hearing loss than right ears Individual behaviors may cause hearing loss to be more pronounced in one ear over the other (Duarte, 2015) −No significant change in hearing observed between year one and year two Noise-induced hearing loss is a gradual process

Results HPDP Questionnaire Figure 4 – Attitudes and beliefs of the control and intervention farmers by year Note – Average response refers to the average response shared by the group for each year where 1 = Strongly Agree; 2 = Agree; 3 = Disagree; and 4 = Strongly Disagree

Results HPDP Questionnaire −General observations ~ 20% of farmers were uncertain about when to use hearing protection Nearly half of farmers reported that they always used hearing protection All farmers tended to agree that important noises would be muffled Consistent with findings by Svensson et al. (2004) −Differences between intervention and control farmers Year one  Control farmers felt more confident about their ability to properly use hearing protection than intervention farmers (p=0.030)  Intervention farmers agreed more strongly that the consequences of hearing loss were severe (p=0.019) Year two  Intervention farmers disagreed more strongly that comfort was a barrier to wearing hearing protection (p = 0.010)  Control farmers agreed more strongly that they used earing protection more while on the job (p = 0.016)

Conclusion Farmers are exposed to hazardous noise and have significant hearing loss Only about 50% of farmers actually reported using hearing protection None of the farmers who participated were exposed to noise in excess of OSHA’s PEL More than half were exposed to noise in excess of NIOSH’s REL A statistically significant change in hearing was not observed Subtle changes in attitudes and beliefs Provision of personal protective equipment (PPE) and PPE training appears to be an innovative approach to reduce hearing loss among farmers Merits further analysis

Acknowledgements Dr. Chandran Achutan, PhD, CIH Mr. Sean Navarrette, MPH This study was supported by a grant from the National Institute for Occupational Safety and Health (U54 OH010162).

References Depczynski, J., Challinor, K., & Fragar, L. (2011). Changes in the hearing status and noise injury prevention practices of australian farmers from 1994 to Journal of Agromedicine, 16(2), doi: / X Duarte, A. S. M., Guimarães, A. C., de Carvalho, G. M., Pinheiro, L. A. M., Ng, R. T. Y., Sampaio, M. H.,... Gusmão, R. J. (2015). Audiogram comparison of workers from five professional categories. Biomed Research International, 2015, doi: /2015/ Indiana Grain LLC. (2008). The American Farmer’s Dirty Little Secret. Retrieved from Rabinowitz, P., M., Galusha, D., Dixon-Ernst, C., Clougherty, J., E., & Neitzel, R., L. (2013). The dose-response relationship between in-ear occupational noise exposure and hearing loss. Occupational & Environmental Medicine, 70(10), doi: /oemed Rein, B. K. (1992). Health hazards in agriculture - an emerging issue. Retrieved from Svensson, E. B., Morata, T. C., Nylén, P., Krieg, E. F., & Johnson, A. (2004). Beliefs and attitudes among Swedish workers regarding the risk of hearing loss. International Journal of Audiology, 43(10), p. Tak, S., & Calvert, G. M. (2008). Hearing difficulty attributable to employment by industry and occupation: An analysis of the national health interview survey--united states, 1997 to Journal of Occupational and Environmental Medicine, 50(1), doi: /JOM.0b013e The Modal Shop, Inc. (2015). Larson Davis Noise Dosimeters. Retrieved from

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