A Comparative Study of Changes in Firefighters Occupational Exposure to Noise. Catherine M. Fitzgerald, RN, MPH Elizabeth H.

Transcription

1 A Comparative Study of Changes in Firefighters Occupational Exposure to Noise Catherine M. Fitzgerald, RN, MPH Elizabeth H. Maples, PhD

2 Disclosures

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5 Firefighters Exposure to Noise 1 million American firefighters Exposure to hazardous levels of intermittent noise from: Sirens, air horns, fire truck engines, building alarms, SCBA alarms, motor vehicle accidents (equipment) Wearing hearing protection a challenge Exposure to noise is complex with considerable variation Other employment

6 Purpose Examine changes that have occurred in firefighters noise exposures in the same service over 15 years

7 Methods Birmingham City Fire & Rescue Service (BCFRS) 648 firefighters 30 stations in four battalions 27 pumpers (Fire Engines) 2 quint trucks 2 Bronto units 16 rescue units

8 Methods Personal noise dosimetry was conducted on 67 firefighters in 1997 and on 69 firefighters in 2012

9 Methods Sampled for full-shift - 24 hours Noise sources were identified and measured in 2012

10 Methods OSHA dosimeter settings Exchange rate: 5 db Frequency weighting: A Response: slow Criterion level: 90 dba Threshold: 80 dba

11 Methods IRB Approval Recruited firefighters from 6 fire stations Informed consent Demographic data Age Gender Length of Service Position on Engine

12 Results: Demographics Year n Male Female Mean Age (Years) Length of Service (Years)

13 Results: Overall Year n MeanTWA (dba) SD (dba) 95% C.I. (dba) p-value < Year n Mean Peak (dbc) SD (dbc) 95% C.I. (dbc) p-value <

14 Results: Station Station n High or Low Call Mean TWA (dba) SD (dba) Range (dba) Mean Peak (dbc) SD (dbc) Range (dbc) Station 1 13 High Station 6 11 High Station High Station High Station High Station 32 7 Low

15 Results: Position Vehicle Position n Mean TWA (dba) 2012 n Mean TWA (dba) 1997 Engine Officer Engine Driver Engine Nozzleman Engine Plugman Truck Officer Truck Driver Truck Utilityman Rescue Officer Rescue Driver

16 Results: Siren & Air-horn Fire Apparatus LA eq (dba) (Outside Vehicle) Peak level (dbc) (Outside Vehicle) LA eq (dba) (Inside Vehicle) Peak level (dbc) (Inside Vehicle) Fire Truck 1 (Siren) Fire Truck 1 (Air horn) Fire Truck 2 (Siren) Fire Truck 2 (Air horn) Fire Engine 1 (Siren) Fire Engine 1(Air horn) Rescue Engine 1 (Siren & Air horn) Rescue Engine 2 (Siren & Air horn) Rescue Engine 3 (Siren & Air horn)

17 Results: Specific Noise Sources Specific Noise Source LA eq (dba) Peak level (dbc) Portable Diesel Generator Personal Alert Safety System (PASS) Alarm Positive PressureVentilation (PPV) Fan Chain Saw Fire Engine Pump Leaf Blower

18 Discussion Significant reduction in the mean 8-hour TWA for noise within this group of firefighters since 1997 (mean difference 8.1 dba, p <0.001) Area monitoring revealed that firefighters can be exposed to intermittent high noise levels. The air horn of fire truck peak level of > 140 dbc. High call volume resulted in higher noise exposures. The stations with the highest average noise exposure are 2 of the busiest fire stations.

19 Discussion In 2012 the truck driver had the highest noise exposure (78.2 dba). The truck driver operates the pump during structural firefighting; the LAeq for the pump was 92.6 dba For 1997 the rescue driver had the highest noise exposure (87.41 dba) In 1997, firefighters were not enclosed in a cab, had direct exposure to the noise Location of siren has also changed

20 Discussion Exposure to loud noise is not only considered a health hazard but can also interfere with speech and communication Results from inside the fire truck and fire engine demonstrated a high noise level that has the potential to interfere with speech and communication.

21 Discussion In 2012, four (5%) of the dosimetry results were greater than the OSHA s action level of 85 dba, none of the measurements were above OSHA s PEL for noise In 1997, seventeen (25%) of the dosimetry results were greater than the OSHA s action limit only one of the measurements was above OSHA s PEL for noise

22 Discussion Results from our study demonstrate similarities with other studies Kirkham (2011)revealed a mean Leq and peak noise levels of 81.1 ± 4.8 dba and ± 5.2 dbc respectively The mean Leq was higher than our study (mean Leq = 77.9 dba) Peak levels reported by Kirkham (137.1 ± 5.2 db) were very similar to the peak levels in our study (137.4 ± 5.2 db) Tubbs (1991) results ranged from dba. The ranges of results from our study were higher dba None of the dosimetry results obtained by Tubbs were above 85 dba

23 Conclusions Changes in firefighters personal exposure to noise in the last fifteen years A significant reduction in the mean 8- hour TWA for noise was observed between the two groups. Reduction may be due to changes in fire-engine design. Monitoring of specific noise sources - exposed to intermittent high noise levels - increased risk of noise induced hearing loss.

24 Limitations Small sample size Sampling conducted in one specific service only Exposure complex with considerable variation Samples not stratified These are the #s, but, what if?

25 Acknowledgements Birmingham City Fire & Rescue Service Lisa McCormick, DrPH Kent Oestenstad, PhD, CIH / Lynn Fancher Jonghwa Oh

26 References National Institute for Occupational Health and Safety. Preventing occupational hearing loss: a practical guide. Washington, DC: US Department of Health and Human Services, Public Health Service, Center for Disease Control and Prevention; WHO. Occupational noise: assessing the burden of disease from work-related hearing impairment at national and local levels. Environmental Burden of Disease Series, No. 9. Geneva: WHO; Rackl, J., and T.N. Decker: Effect of firetruck noise on firefighters' hearing. J. Aud. Res. 18(4): (1978) Jones and Bartlett: Fundamentals of Fire Fighter Skills, Second Edition. Quincy, MA.NFPA (2009). Reischl U., H.S. Bair Jr. and P. Reischl: Fire fighter noise exposure. Am. Ind. Hyg. Assoc. J. 40: (1979). Tubbs RL and M.S. Flesch: Health hazard evaluation: Newburgh fire department. Cincinnati, OH: National Institute for Occupational Health and Safety. HHE Report No , (1982). Tubbs RL.: Health hazard evaluation: the city of New York fire department. Cincinnati, OH: National Institute for Occupational Safety and Health. HHE Report No , (1985). Tubbs, R. L.: Noise and hearing loss in firefighting. Occup. Med. 10(4): (1995). Tubbs RL.: Occupational noise exposure and hearing loss in fire fighters assigned to airport fire stations. Am. Ind. Hyg. Assoc. J. 52(9):372-8 (1991). Kirkham, T. L., M. W. Koehoorn, H. Davies and P. A. Demers: Characterization of Noise and Carbon Monoxide Exposures among Professional Firefighters in British Columbia. Ann. Occup. Hyg. 55: (2011). National Institute for Occupational Safety and Health (NIOSH) Criteria for a Recommended Standard, Occupational Noise Exposure Revised Criteria June 1998, DHHS (NIOSH) Publication No Fancher, L.: Predictive Hearing Loss based on distribution of noise exposure for a population of firefighters. A research project report. Birmingham, Alabama. Unpublished (1997). Occupational Safety and Health Administration (OSHA) Technical Manual Section II, Chapter 5, Noise Measurement. OSHA. Washington, DC. (accessed 19 July 2012) Larsby B, M. Hällgren, B. Lyxell and S. Arlinger: Cognitive performance and perceived effort in speech processing tasks: effects of different noise backgrounds in normal- hearing and hearing-impaired subjects. Int. J. Audiol. 44(3):131-43(2005). US Occupational Safety and Health Administration (OSHA). Occupational noise exposure. Standard In: Regulations; Standards, Code of Federal Regulations (CFR) 29. Washington, DC: OSHA. (accessed 29 July 2012). Nelson DI, R.Y. Nelson, M. Concha-Barrientos and M. Fingerhut: The global burden of occupational noise-induced hearing loss. Am J Ind Med. 48(6): (2005).

27 Questions? ds