Audiologists and other health professionals around the world have recognized for decades that noise exposure is a health hazard. Governments worldwide control the amount of noise exposure for known hazard occupations such as manufacturing, construction, and other high noise work places.
Just as noisy and sometimes much worse, recreational noises such as firearms, motorcycles, race tracks, music, and other loud activities also contribute to the a worldwide epidemic of noise exposure. People around the world suffer from preventable hearing loss due to high workplace and recreational noise levels everyday.
Recognizing that inadequately controlled noise presented a growing danger to the health and welfare of the world population, particularly in urban areas, governments in the early 1970s began regulating the amount of noise exposure that workers were allowed each day. At the time, the major sources of noise included transportation vehicles and equipment, machinery, appliances, and other products in commerce.
In the US, the Noise Control Act of 1972 established a national policy to promote an environment for all Americans to be free from noise that jeopardizes their health and welfare. The Act also served to
- establish a means for effective coordination of Federal research and activities in noise control
- authorized the establishment of Federal noise emission standards for products distributed in commerce; and
- provide information to the public respecting the noise emission and noise reduction characteristics of such products.
Other countries, particularly in Europe soon followed and passed legislation similar to the US statutes such as Netherlands (1979), France (1985), Spain (1993), and Denmark (1994). Subsequently, other countries have followed in regulating noise in their regions, particularly those that are a health hazard. While the US led the initial legislation, recent studies estimate that its regulations are about 20 years behind that of Europe due to reduced funding. The rest of the world is significantly behind in their national control of noise and the exposure of their population.
Probably one of the areas that has had the least regulation worldwide is farming. While under many of the same regulations as other businesses, the enforcement of noise regulations in farm businesses seems to be lacking worldwide, probably due to the rural nature of these businesses. Although farmers are increasingly aware of reputable research in noise induced hearing loss (NIHL) that has demonstrated that those who live and work on farms have had significantly higher rates of hearing loss than the general population, they often do not use hearing protection devices.
Farming is ranked among the top occupations with the highest risk for hearing loss, mainly due to the non-use of hearing protection devices (Achutan, 2014). It has been shown that hearing loss is prevalent among adults in farming communities, with some evidence that it begins in childhood. Renick, Crawford & Wilkins (2009) conducted baseline data, including audiometric thresholds that were collected from US youths living on farms in 1994-1996 (n = 212) with follow-up in 2003-2004 (n = 132). Youths in this study had a higher prevalence of hearing loss when compared to nationally-representative data, and nearly 50% of them exhibited high-frequency hearing loss (mainly at 6 kHz). The prevalence of noise-induced threshold shifts, characterized by an audiometric notch, was nearly twice that of the national sample. These data indicate that hearing loss is common not only in adult farmers, but also in teenagers living on farms and other headed vocational training. However, the actual age when NIHL begins among farmers remains unknown.
Farming remains among the occupations recognized as having the highest risks for hearing loss and probably the least control over the noise due to the rural nature of this business and this is seen in clinics around the world where farmers are seeking assistance with there hearing, particularly as they age. Machinery such as tractors, forage harvesters, silage blowers, chain saws, skid-steer loaders, grain dryers, squealing pigs and guns are some of the most typical sources of noise on the farm. Studies suggest that lengthy exposure to these high sound levels have resulted in noise-induced hearing loss to farmworkers of all ages. Hearing loss is not as dramatic nor as sudden as an injury from a tractor overturn or machine entanglement, but it is permanent and seen in clinics around the world routinely.
More Stringent Regulations Proposed
In European studies such as, Slinwinska-Kowalska & Davis (2012), where a 3-year evaluation of various professions led to the adoption of a draft European standard had been developed by the relevant working group in CENELEC European Committee for Electrotechnical Standardization. In this document, a sound level of 85 dBA is considered to be safe under all conditions. The sound level can be increased up to a maximum average of 100 dBA, but in that case the user has to be provided with warnings about the risks, which should be repeated after each 20 hours of listening time. While similar to US standards, based upon the research Europe has chosen bit more stringent exposure standards.
While noise over-exposure is one of the largest hearing health hazards on the farm, the increased use of migrant workers as farmhands has greatly increased in the US. These workers are usually not educated on the hazardous effects of farm noise.
Next week in Part II, Hearing International will explore the efforts toward their education and how hearing conservation is being presented to this new classification of exposed workers.
Achutan, C., (2014). Introducing a point source noise prevention to increase the use of HPDs. CAHOC Update, Vol 26, #2. Retrieved June 23, 2015: http://www.caohc.org/updatearticles/summer2014.pdf
Renrick, K., Crawford, J., Wilkins, J., (2009). Hearing loss among Ohio farm youth: a comparison to a national sample. American Journal of Industrial Medicine, Vol 52(3). pp 233-239. Retrieved June 23, 2015: http://www.ncbi.nlm.nih.gov/pubmed/19089836
Rosemberg M., McCullagh M., Nordstrom M. (2015). Farm and rural adolescents’ perspective on hearing conservation: Reports from a focus group study. Noise Health, 17:134-40: Retrieved June 23, 2015: http://www.noiseandhealth.org/article.asp?issn=1463-1741;year=2015;volume=17;issue=76;spage=134;epage=140;aulast=Rosemberg
Slinwinska-Kowalska, M & Davis, A. (2012). Noise Induced Hearing Loss. Noise and Health. Volume 14, Issue 61, pp. 274-280. Retrieved June 23, 2015: http://www.noiseandhealth.org/article.asp?issn=1463-1741;year=2012;volume=14;issue=61;spage=274;epage=280;aulast=Sliwinska-Kowalska
U.S. Department of Labor (2015). Agricultural Operations: Noise. Occupational Safety and Health Administration. Safety and Health Topics. Retrieved June 22, 2015: https://www.osha.gov/dsg/topics/agriculturaloperations/hazards_controls.html
Sherman, N., (1980). Fonts in use. Retrieved June 23, 2015: http://fontsinuse.com/uses/4139/noise-control-a-guide-for-workers-and-employe