Transcript Metal Mine - National Hearing Conservation Association

Benjamin Roberts
([email protected])
First iron mine
~43,000 years ago!
http://www.cdc.gov/niosh/mining/UserFiles/statistics/10g03aaa_1911-2010.svg
http://www.cdc.gov/niosh/mining/UserFiles/statistics/13g10aaa.svg
 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?
https://xkcd.com/552/
 Grant # R21OH0 10482: 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
MSHA
OSHA
NIOSH
 Over 600,000 noise measurements from MSHA!
 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 13. 2000
MSHA PEL measurements only.
< 2000
≥85
dBA
≥90
dBA
≥100
dBA
≥105
dBA
N
Coal Mine
Metal Mine
61.07%
52.66%
24.09%
27.14%
1.62%
5.00%
0.30%
1.79%
92,488
19,032
Non-Metal
53.51%
55.66%
23.11%
23.64%
1.92%
2.02%
0.43%
0.48%
205,491
Overall
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%
27.25%
7.41% 0.57%
12.00% 1.88%
0.15%
0.72%
101,546
Overall
216,513
Percentage of Job Title Distribution
Job Category
MSHA PEL
Unexposed
0.11%
Construction (47-(1-4)xxx)
2.19%
Miners (SOC: 47-5xxx)
78.74%
Maintenance (SOC: 49-xxxx)
5.54%
Production (SOC: 51-xxxx)
21.05%
Material Movers (SOC: 53-xxxx)
11.37%
MSHA AL
0.13%
3.06%
84.68%
5.88%
0.77%
5.48%
Total Sample Size
110,309
546,062
Exceedance fraction by broad occupational groups
MSHA PEL
>85
>90
>100
Unexposed
24.8%
9.1%
0.8%
Miners
46.5%
20.8%
2.2%
Construction
23.5%
7.1%
0.6%
Maintenance
31.9%
10.9%
1.2%
Production
31.9%
11.2%
1.0%
Material Movers
39.4%
12.9%
0.7%
Unexposed
Miners
Construction
Maintenance
Production
Material Movers
14.4%
53.5%
31.1%
36.7%
33.6%
37.5%
MSHA AL
4.3%
28.6%
28.6%
18.8%
18.2%
15.9%
1.4%
4.5%
1.3%
3.5%
4.8%
1.9%
>105
0.2%
0.7%
0.1%
0.4%
0.4%
0.1%
N
618
429,992
11,960
30,225
11,168
62,099
0.7%
1.7%
0.4%
1.4%
2.9%
0.8%
139
93,410
3,377
6,482
854
6,047
Year
Year
Job Title
Job Title
Mine
Type
Exposure
What’s
being
mined
Exposure
 MSHA PEL Only
𝐸𝑠𝑡𝑖𝑚𝑎𝑡𝑒𝑑 𝑁𝑜𝑖𝑠𝑒 𝐸𝑥𝑝𝑜𝑠𝑢𝑟𝑒 𝑑𝐵𝐴
= 𝛽0 + 𝛽1 × 𝑦𝑒𝑎𝑟 𝑐𝑒𝑛𝑡𝑒𝑟𝑒𝑑 + 𝛽2−61
× 𝑗𝑜𝑏 𝑡𝑖𝑡𝑙𝑒 𝑠𝑜𝑐 + 𝛽62−64 × 𝑚𝑖𝑛𝑒𝑡𝑦𝑝𝑒
+ 𝛽65−67 × 𝑤ℎ𝑎𝑡 ′ 𝑠 𝑏𝑒𝑖𝑛𝑔 𝑚𝑖𝑛𝑒𝑑
 r2=0.1424
 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 Title
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
Predicted
79.2
80.6
80.6
85.1
78.8
84.0
82.8
79.6
84.3
81.3
Dataset
81.8
82.7
82.0
85.9
79.4
84.2
82.7
79.3
84.1
81.0
Difference
-2.6
-2.0
-1.3
-0.8
-0.6
-0.3
0.1
0.2
0.3
0.3
84.7
82.7
84.5
84.0
82.0
83.5
0.7
0.7
1.0
 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 # R21OH0 10482: Development of a
US/Canadian Job Exposure Matrix (JEM) for Noise

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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:
http://www.cdc.gov/niosh/mining/UserFiles/works/pdfs/hlitmi.pdf
4.
Rappaport SM, Kromhout H, Symanski E. Variation of Exposure Between Workers in
Homogeneous Exposure Groups. Am Ind Hyg Assoc J. 1993;54(11):654–62.
5.
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 2003. J
Occup Environ Med. 2008;50:46–56.
6.
Tak S, Davis RR, Calvert GM. Exposure to hazardous workplace noise and use of
hearing protection devices among US workers--NHANES, 1999-2004. Am J Ind Med [Internet].
2009 May [cited 2014 May 29];52(5):358–71. Available from:
http://www.ncbi.nlm.nih.gov/pubmed/19267354
7.
SUBCHAPTER M — UNIFORM MINE HEALTH REGULATIONS PART 62 —
OCCUPATIONAL NOISE. 30 CFR 62; 2014.
8.
Mining Topic: Hearing Loss Prevention Overview [Internet]. 2015. Available from:
http://www.cdc.gov/niosh/mining/topics/HearingLossPreventionOverview.html
9.
Title: 30 Mineral Resources Parts 1 to 199. United States; 2014.

Slide 2: Google maps; http://news.psu.edu/sites/default/files/styles/threshold992/public/old%20time%20mining%20photo.jpg?itok=GiwwtbAI;
http://news.psu.edu/photo/348445/2015/03/16/low-seam-continuous-mining-machine;
https://en.wikipedia.org/wiki/Hematite#/media/File:WLA_hmns_Hematite.jpg

Slide 9: https://metrouk2.files.wordpress.com/2015/04/89272285.jpg?w=620&h=414&crop=1

 That’s great but…
47-1011:
“Supervisors of
Extraction Workers”
47-5021:
“Earth Drillers, Except
Oil and Gas”
47-5041:
“Continuous Mining
Machine Operator”
47-5061:
“Roof Bolters, Mining”
49-3042:
“Mobile Heavy
Equipment
Mechanics”
49-9071:
“Maintenance and
Repair Workers”
53-3032:
“Heavy Truck Drivers”
53-7062:
“Laborers and Material
Movers, Hand”
 What if we only look at 2000 and later?
47-1011:
“Supervisors of
Extraction Workers”
47-5021:
“Earth Drillers, Except
Oil and Gas”
47-5041:
“Continuous Mining
Machine Operator”
47-5061:
“Roof Bolters, Mining”
49-3042:
“Mobile Heavy
Equipment
Mechanics”
49-9071:
“Maintenance and
Repair Workers”
53-3032:
“Heavy Truck Drivers”
53-7062:
“Laborers and Material
Movers, Hand”