Benjamin Roberts

e#/media/File:WLA_hmns_Hematite.j pg First iron mine ~43,000 years ago!

76% of mine workers are exposed to noise that required them to “speak in a raised voice” (Tak et al. 2009) 24.3% of mine workers interviewed in the National Health Interview Survey (NHIS) reported having hearing difficulty (Tak et al. 2008) This is the second highest employment sector, after railroad workers (34.8%) 11.4% of the total working population reported hearing difficulty

Q1: Have noise levels decreased over the years? If so, by how much? Q2:What is the 8hr time weighted average (TWA) exposure for different job groups? How has this changed over the years?

Grant # R21OH : Development of a US/Canadian Job Exposure Matrix (JEM) for Noise Currently just over 1 million full shift noise measurements Data from industry, government, and the published literature Over 600,000 noise measurements from MSHA! MSHA OSHANIOSH

A lot of effort was put in to data cleaning and standardizing job titles Job titles -> 2010 Standard Occupational Classification (SOC) Industry -> 2012 North American Industry Classification System (NAICS) Mine type, year, exposure data all provided by MSHA

656,371 full shift noise measurements 546,062 – MSHA PEL PEL = 90 dBA, ER = 5, Threshold = 90 dBA 110,309-MSHA Al AL =85 dBA, ER = 5 dB, Threshold = 80 dBA 302 string job titles -> 61 SOC titles 111 string “industry” titles -> 5, 4-digit NAICS codes The OSHA PEL data provided mine type information for some measurements Facility: 63,068; Surface: 339,288; Underground: 143,706

1999- New MSHA noise standard released; went in to effect Sept

MSHA PEL measurements only. < 2000 ≥85 dBA ≥90 dBA ≥100 dBA ≥105 dBA N Coal Mine 61.07%24.09%1.62%0.30% 92,488 Metal Mine 52.66%27.14%5.00%1.79% 19,032 Non-Metal 53.51%23.11%1.92%0.43% 205,491 Overall 55.66%23.64%2.02%0.48% 317,011 ≥2000 Coal Mine 31.49%15.89%3.06%1.26% 110,175 Metal Mine 40.59%19.87%2.65%0.38% 4,792 Non-Metal 22.02%7.41%0.57%0.15% 101,546 Overall 27.25%12.00%1.88%0.72% 216,513

Percentage of Job Title Distribution Job CategoryMSHA PELMSHA AL Unexposed0.11%0.13% Construction (47-(1-4)xxx)2.19%3.06% Miners (SOC: 47-5xxx)78.74%84.68% Maintenance (SOC: 49-xxxx)5.54%5.88% Production (SOC: 51-xxxx)21.05%0.77% Material Movers (SOC: 53-xxxx)11.37%5.48% Total Sample Size546,062110,309

Exceedance fraction by broad occupational groups MSHA PEL >85>90>100>105N Unexposed24.8%9.1%0.8%0.2%618 Miners46.5%20.8%2.2%0.7%429,992 Construction23.5%7.1%0.6%0.1%11,960 Maintenance31.9%10.9%1.2%0.4%30,225 Production31.9%11.2%1.0%0.4%11,168 Material Movers39.4%12.9%0.7%0.1%62,099 MSHA AL Unexposed14.4%4.3%1.4%0.7%139 Miners53.5%28.6%4.5%1.7%93,410 Construction31.1%28.6%1.3%0.4%3,377 Maintenance36.7%18.8%3.5%1.4%6,482 Production33.6%18.2%4.8%2.9%854 Material Movers37.5%15.9%1.9%0.8%6,047

Clearly there is a relationship between year and exposure…. But what about: Type of mine (Facility, Surface, Underground)? What’s being mined for (Coal, Metal, Non-metal)? YearJob TitleExposure YearJob Title Mine Type What’s being mined Exposure

MSHA PEL Only r 2 = Coefficients (in dBA) Year Centered (to 1996) = (-0.35) Facility (Reference) < Surface (0.10) < Underground (1.59) Non-Metal (-0.92) < Coal (Reference) < Metal (0.24)

Validated using the holdout method 70% of the data went to training set 30% went to test set On average, the absolute mean difference between the model predictions and test set was 4.0 dBA Not surprising given the wide date range and the inherent variability in occupational exposures (Rappaport et al. 1993)

Job TitlePredictedDatasetDifference Crushing, Grinding, and Polishing Machine Mining Machine Operators, All Other Cutting and Slicing Machine Setters, Operator Extraction Workers, All Other Mine Shuttle Car Operators Mine Cutting and Channeling Machine Operator Continuous Mining Machine Operators Mining Machine Operators Roof Bolters, Mining Explosives Workers, Ordnance Handling Loading Machine Operators, Underground Mining Earth Drillers, Except Oil and Gas Helpers--Extraction Workers

Noise exposure in the mining industry has been decreasing There still many workers who are potentially exposure to hazardous noise And a small number of workers may actually worse off While we are most concerned with miners, there are support occupations that may also be exposed Predicted exposures created using this data tends to is pretty good for mining jobs Not as good for other jobs from other professions

Continue updating the JEM as new data is received Work on developing more sophisticated models to (hopefully) improve prediction ability Provide a publicly accessible website where workers and other interested parties can view this information

Rick Neitzel Kan Sun Stephanie Sayler Rachel Long National Institute of Occupational Safety and Health Grant # R21OH : Development of a US/Canadian Job Exposure Matrix (JEM) for Noise

1. Bauer ER, Babich DR, Vipperman JR. Equipment Noise and Worker Exposure in the Coal Mining Industry. 2006;(Inf. Cir. 9492). 2. Bauer ER. Hearing loss greater than 25 dB. Hearing loss greater than. 3. Matetic RJ, Randolph R, Kovalchik PG. Hearing Loss in the Mining Industry: The Evolution of NIOSH and Bureau of Mines Hearing Loss Research [Internet]. Available from: 4. Rappaport SM, Kromhout H, Symanski E. Variation of Exposure Between Workers in Homogeneous Exposure Groups. Am Ind Hyg Assoc J. 1993;54(11):654– Tak S, Calvert GM. Hearing difficulty attributable to employment by industry and occupation: an analysis of the National Health Interview Survey--United States, 1997 to J Occup Environ Med. 2008;50:46– Tak S, Davis RR, Calvert GM. Exposure to hazardous workplace noise and use of hearing protection devices among US workers--NHANES, Am J Ind Med [Internet] May [cited 2014 May 29];52(5):358–71. Available from: 7. SUBCHAPTER M — UNIFORM MINE HEALTH REGULATIONS PART 62 — OCCUPATIONAL NOISE. 30 CFR 62; Mining Topic: Hearing Loss Prevention Overview [Internet] Available from: 9. Title: 30 Mineral Resources Parts 1 to 199. United States; 2014.

Slide 2: Google maps; 992/public/old%20time%20mining%20photo.jpg?itok=GiwwtbAI; /public/old%20time%20mining%20photo.jpg?itok=GiwwtbAI Slide 9:

That’s great but… : “Supervisors of Extraction Workers” : “Earth Drillers, Except Oil and Gas” : “Continuous Mining Machine Operator” : “Roof Bolters, Mining” : “Mobile Heavy Equipment Mechanics” : “Maintenance and Repair Workers” : “Heavy Truck Drivers” : “Laborers and Material Movers, Hand”

What if we only look at 2000 and later? : “Supervisors of Extraction Workers” : “Earth Drillers, Except Oil and Gas” : “Continuous Mining Machine Operator” : “Roof Bolters, Mining” : “Mobile Heavy Equipment Mechanics” : “Maintenance and Repair Workers” : “Heavy Truck Drivers” : “Laborers and Material Movers, Hand”