Time for a Paradigm Shift in Hearing Loss Prevention William J. Murphy National Institute for Occupational Safety and health National Occupational Research Agenda Hearing Loss Prevention Research Cross Sector The findings and conclusions in this presentation have not been formally disseminated by the National Institute for Occupational Safety and Health and should not be construed to represent any agency determination or policy.
Background - US Occupational Noise Exposure
From: The Nature and Effects of Noise by Alice H. Suter. http://www.ilocis.org/documents/chpt47e.htm#JD_Figure47.1
Strategic Goals (circa 2007) 1. Surveillance 2. Develop Engineering Controls to Reduce Noise Exposure 3. Reduce Hearing Loss Through Interventions Targeting Hearing Protection Devices 4. Develop Evidence-based Best Practices for Hearing Loss Prevention Programs 5. Identify Hearing Loss Risk Factors Through Epidemiological Research
Strategic Goals (circa 2007) 1. Surveillance 2. Develop Engineering Controls to Reduce Noise Exposure 3. Reduce Hearing Loss Through Interventions Targeting Hearing Protection Devices 4. Develop Evidence-based Best Practices for Hearing Loss Prevention Programs 5. Identify Hearing Loss Risk Factors Through Epidemiological Research
Surveillance – Risk of Hearing Loss • Created Occupational Hearing Loss Surveillance program • Bureau of Labor Statistics • Reduction of STS from 28,000 to 18,000 in OSHA Form 300
• Established new estimates for exposed workers: • 22 million workers exposed to hazardous noise
Surveillance – Hearing Loss Prevalence • Prevalence ratios for hearing loss amongst workers in different industries between 19 and 24%. • Self-reported Hazardous Noise Exposure in Mining had highest percentage with 76% of workers
Surveillance – Noise Exposures
Adapted from “Exposure to hazardous workplace noise and use of hearing protection devices among US workers--NHANES, 1999-2004.” Tak S1, Davis RR, Calvert GM., Am J Ind Med. 2009 May;52(5):358-71.
Engineering Control of Noise
Engineering Control of Noise • Noise Reduction in Mining Machinery • Surveys of noisy equipment • Development of new controls • Advanced measurement capabilities
• Noise Reduction in Construction • Sound power measurements of powered hand tools • Buy Quiet NIOSH topic page
• Noise Reduction in Manufacturing
• Engineering Noise Control Case Study • Buy Quiet video for manufacturing
Engineering Noise Control in Mining • Hemi-anechoic chamber • Brüel & Kjaer beamforming array
Structural Modeling
• Source path contribution
• ANSYS noise radiation and vibration modeling • Commercialized noise controls
• Dual sprocket chain for continuous mining machine • 35% market penetration for Joy Global • Drill-bit isolator • Corry Rubber, Kennametal
Dual Sprocket Chain
Drill Bit Isolator
Engineering Noise Control in Construction • Noise control at the source
• Jackhammer noise controls • No-racket Jacket® • Damping of chisels • Noise control boot • Pile-driving assessment • Pneumatic nail gun assessments • Nail Gun Safety: A Guide for Construction Contractors
Noise Control in Manufacturing NIOSH received a confidential HHE request from employees to evaluate noise exposures Company manufactured galvanized steel conduit with diameters ranging from 0.25” to 4.0” Plant opened in 2005 in a new 400,000 ft2 building The plant had 168 production employees
Noise Control in Manufacturing Metal Conduit Most noise was generated by: • metal conduit rolling into or dropping onto other conduit • metal conduit striking metal parts on production equipment • operation of production equipment • a steam cannon which used pressurized steam to clear fluid from inside the conduit
Noise Control in Manufacturing - Dosimetry
Noise Control in Manufacturing – Dosimetry Results Range of full shift time-weighted average personal noise dosimetry measurements (dBA) Department
N
NIOSH REL
OSHA AL
OSHA PEL
Bundler
2
92.9 - 94.8
89.3 - 90.9
87.8 - 89.8
Hot Dip Extractor
2
99.0 - 102.7
93.4 - 95.6
92.0 - 94.7
Hot Dip Operator
1
101.2
95.2
94.1
Hot Dip Laborer
1
93.1
89.3
84.3
Hot Dip Loader
2
90.5 - 94.2
87.1 - 91.5
85.2 - 91.1
Maintenance
Maintenance
4
84.7 - 96.7
78.3 - 89.7
72.2 - 88.3
Shipping
Material Handler
6
88.3 - 91.5
85.7 - 88.2
81.5 - 84.9
Packaging Operator
2
87.3 - 94.4
84.7 - 87.8
79.6 - 83.3
Saw Operator
2
91.2 - 92.4
88.2 - 90.3
86.0 - 88.2
Threader Operator
2
90.5 - 90.7
87.7 - 89
86.3 - 86.4
Threading Inspector
1
89.8
86.1
83.1
Bander
4
92.6 - 97.1
88.7 - 95.4
87.2 - 94.9
End Finisher
3
86.7 -97.3
83.6 - 93.2
77.1 - 92.5
Mill Operator
2
86.9 - 90.0
84.2 - 87.4
76.9 - 83.2
Utility
1
86.3
81.7
76.3
NIOSH REL = 85
OSHA AL = 85
OSHA PEL = 90
Galvanizing
Hot Dip
Threading
Welding
Job Title
Noise Exposure Limits
Noise Control in Manufacturing – Results/Discussion Full shift noise exposures for employees in all job titles were above the NIOSH REL and nearly all were also above the OSHA AL Using NIOSH REL measurements to determine which employees are required to wear hearing protection would protect more workers from hearing loss The company required hearing protection for employees in production departments Employees were offered three different types of foam insert ear plugs and one type of ear muff
Noise Control in Manufacturing – Results/Discussion Results/Discussion
Ear plugs or ear muffs alone may not provide adequate hearing protection for employees working near the steam cannon because peak noise levels were above 136 decibels and employees noise exposures were above 100 dBA TWA
Noise Control in Manufacturing – Results/Discussion Our review of audiograms from 56 employees showed that five employees had OSHA-defined hearing threshold shifts, but 11 employees had NIOSH-defined hearing threshold shifts Hearing loss results may indicate that employees are not adequately protected, either because they are not wearing hearing protection or not wearing it properly We observed that some employees in high noise areas did not wear hearing protection or properly insert foam ear plugs We also observed external contractors working near the steam cannon did not wear any hearing protection
Noise Control in Manufacturing - Recommendations Implement engineering controls to reduce noise exposures • Reduce distance that conduit rolls or drops before striking other conduit • Decrease speed at which conduit rolls before striking other conduit • Replace metal pickups on conveyor chains with nylon pickups • Increase thickness of metal stop plates to increase damping • Construct partial enclosure or barrier at steam cannon
Noise Control in Manufacturing -Recommendations Require employees working near the steam cannon to wear ear plugs and muffs Advise contractors on hearing protection requirements Retrain employees on how to properly insert foam hearing protectors Give supervisors responsibility and accountability for ensuring proper use of hearing protection Review and track hearing loss at all audiometric test frequencies and use both NIOSH and OSHA criteria to identify hearing threshold shifts
Noise Control Manufacturing NIOSHin Followback Site Visit – Follow up Return site visit two years after first site visit to learn about changes made after the HHE The company had implemented the following noise controls: • Installed fully enclosed operator booth on north side of steam cannon – noise levels inside the booth were several decibels lower than outside • Attached nylon composite stop plates to metal stop plates to reduce impact noise generated when conduit struck stop plate • Developed plans to also install an operator booth on south side of steam cannon
Rodriguez M, West CA, Brueck SE [2006] Evaluation of Worker Noise Metalworking Fluids, Welding Fumes and Acids During Metal Conduit Manufacturing. NIOSH HHE 2006-0332-3058
Evidence-Based Best Practices • Audiometric test protocols • Educating management • Recommendations for HLPP • Cochrane Systematic Review • Workplace Solutions • NIOSH Science Blogs • Best Practices
• Safe-In-Sound Award • Buy Quiet Program
Recipient Pratt & Whitney Domtar Paper Company Montgomery County Water Services Sensaphonics
• Award program developed as a Public Health Practice NORA project • Manufacturing, construction, services • Innovation in hearing loss prevention
• Promotes solutions for noise control and hearing loss prevention • Program partnered with NHCA • Eighth year of the program
Etymotic Research NYC Department of Environmental Protection Kris Chesky Fort Carson Shaw Industries Colgate Palmolive 3M Hutchinson Vulcan Materials Johns Manville Dangerous Decibels Benjamin Kanters Northrup Grumman United Technologies Mahrt Mill Employees of Mead Westvaco Corporation
Year 2009 2009
Category Manufacturing Manufacturing
2009
Services
2009
Innovation
2010
Manufacturing
2010
Construction
2010 2010 2011 2012 2012 2013 2013 2013 2014 2014 2015
Services Services Manufacturing Manufacturing Manufacturing Manufacturing Manufacturing Innovation Services Manufacturing Manufacturing
2015
Manufacturing
What is Buy Quiet? • Buy Quiet is a prevention initiative which: • Encourages companies to purchase or rent quieter machinery and tools to reduce worker noise exposure. This is accomplished when new businesses start up or when older equipment is replaced. • Provides information on equipment noise levels, so companies can buy quieter products that make the workplace safer. • Encourages manufacturers to design quieter equipment by creating a demand for quieter products.
Benefits of Buy Quiet • Reducing the risk of hearing loss. • Reducing the long-term costs of audiometric testing, personal protective equipment, and workers compensation. Conservative estimates provide $100 per dBA of savings when purchasing the quieter product. This savings is applicable across a wide variety of machinery and equipment. • Helping companies comply with OSHA and other noise regulation requirements. • Reducing the impact of noise on the community.
Buy Quiet Promotional Efforts • NIOSH launched Buy Quiet web resources • Providing information on Buy Quiet, equipment noise levels, and components of a Buy Quiet company program • NIOSH Buy Quiet Website http://www.cdc.gov/niosh/topics/buyquiet/ • Educational video for manufacturing/construction industry • Buy Quiet posters for manufacturing/construction businesses and workers
• NIOSH will continue promotional efforts with Buy Quiet partners and social media targeting construction and manufacturing industry
Engineering noise controls – Future research • Case studies
• Manufacturing • Construction • Service Sector
• Generalizable Research • Building library of solutions • Building partnerships • Optimizing Dissemination • Promoting Buy Quiet Program
Questions? William J. Murphy, Ph.D. National Institute for Occupational Safety and Health Hearing Loss Prevention Team 1090 Tusculum Ave. Mailstop C-27 Cincinnati OH 45226-1998
[email protected] 