Transcript 1.2 OAEs_Mototolo verification exercise feedback

Feedback on verification exercise for proposed
leading practice of supplements to a mine Hearing
Conservation Programme that include the use of
OAEs, coaching of employees and custom-moulded
Hearing Protection Devices
2 October 2013
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Outline
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Background
Methodology
Advantages
Findings
Challenges & Refinements required
Audiogram analysis
Conclusion
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Background
MOSH Industry Team mandated MOSH Noise team to
conduct verification exercises on proposed leading
practices
Glencore Mototolo proposed:
Supplements to a mine Hearing Conservation
Programme that includes the use of OAEs, coaching of
employees and custom-moulded HPDs
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Advantages identified-OAEs
Early identification of hearing loss
Detects inner ear damage before hearing loss is
evident on an audiogram
Measures in smaller units than audiogram
Can be used to check effectiveness of HPDs
Coaching of employees based on OAE measures
Enhances employee knowledge and motivation to
prevent hearing loss
Increased link between the workplace and health
Increased integration of the HCP
Advantages identified- HPDs
Best practice = Risk-based medical examination
(RBME)
Personalised fitting of the HPDs
Considers individual differences amongst ears
Increased ownership of the use of HPDs
Seal-fit test
Increased chance that planned attenuation levels
achieved
Annual maintenance
Check on the condition of the HPD
Opportunity to counsel about the care of and use
Methodology
Objectives
Gather all the necessary information
Examine the details and the effectiveness
Identify the required refinements
Establish the validity of leading practice in the industry
Methodology
Verification exercise included
Site visits to Glencore Mototolo
Interviews with the key stakeholders
Observing the processes and procedures
Analysis of historical employee audiogram and OAE
and coaching data
Identify the required refinements
Recommendations on refinements needed
Findings
A commercial company provides supplements to the mine
Hearing Conservation Programme.
The programme uses a 4-leaf clover approach that is
aimed at action in four different areas namely:
Noise level measurement: personal noise levels of the
employees are measured by the mine Occupational
Hygiene department and must be integrated into the
programme in order to facilitate the correct choice of
attenuation levels on HPDs.
Findings
HPDs: In the case of Mototolo custom-moulded HPDs are
supplied by an affiliated supplier.
The programme provides a personalized fitting of the HPD
and a seal fit-test to ensure that the HPD seals in the
employee’s ear.
The filter in the custom-moulded HPD should be chosen
based on the attenuation needed for the noise exposures of
the employee to ensure that neither over-protection nor
under-protection occurs.
Coaching of the employee on the care of and the correct
fitting of the HPDs is provided by the programme
representative.
Findings
Otoacoustic Emissions measurements (OAEs):
At the same time as when the HPD is fitted, a test known
as Otoacoustic Emissions (OAEs) is used to measure the
functioning of the inner ear, the part of the ear where noise
causes damage.
Since OAEs can indicate a reduction in inner ear function
before a hearing loss is identified on an audiogram, the
OAE test method can be an early indicator of hearing loss.
Challenges - 1
Audiogram test results, Noise level measurements, HPD
records, OAE test results and coaching records are not
integrated in a way that facilitates an evaluation of the value
added by each aspect of the programme i.e. no statistics
available that indicates the programme is reducing NIHL or
that the costs involved are adding value to the Hearing
Conservation Programme at the mine.
Establishing a link between all the available databases and
developing reporting systems that will facilitate evaluation
and proactive management of the HCP will address this
challenge.
Challenges-2
Due to the lack of integration there is inefficiency and
duplication of some processes:
Duplication - counseling/coaching
Inefficiency - lack of effective use of OAEs early
identification of NIHL
- Attenuation is not linked to the personal
noise exposure level of the employee
Integration of all aspects of HCP will address these
challenges.
Challenges - 3
The quality control measures
Documented and certified attenuation value
Documented evidence of servicing procedure
Documented evidence of seal-fit test
Documented coaching content and procedures
Documented outcome of coaching
Quality control of some processes not adequate e.g. no
tympanometry; attenuation of HPDs, calibration and
maintenance documentation not available; time period
between impression and fitting; seal-check outcome.
Implementation of these quality control measures will
address this challenge.
Challenges - 4
Best practice for HPD fitting requires that employees have a
choice of HPDs in order to ensure fitting comfort and ownership
of the HPD and compliance with wearing them.
Some of Mototolo employees do not have custom-moulded
HPDs – the procedures and policies for these need to be
integrated into the system.
The complaint processes and records of the complaints for use
in quality control of the system are not documented.
The alternative disposable HPDs that are available for
employees that do not want or cannot wear custommoulded HPDs for valid reasons is not well-defined and if
improved will enhance the HPD management system.
Audiogram analysis-Average age at time of test
Average Age at time of measure
36
35
35
34
34
33
33
32
Total
2008
33
2009
34
2010
34
2011
34
2012
35
Average for both ears for
all audiograms
0
POST-HPD/OAE
Average for both ears for
all audiogram
PRE- HPD/OAE
0
10
10
20
20
30
30
2011
2008
2009
40
40
2012
2010
50
50
60
Avg
05K
Both
2008 9.9
2009 9.9
2010 9.68
2013
Avg
1K
Both
8.52
9
8.16
Avg
2K
Both
10.9
11.7
11.1
Avg
3K
Both
14.7
15.6
14.8
Avg
4K
Both
17.6
18.3
17.4
Avg
6K
Both
21.3
23.1
23.3
Avg
8K
Both
18.6
20.3
20.4
60
Avg
05K
Both
2011 9.56
2012 10.2
2013 9.33
Avg
1K
Both
7.76
8.41
8.16
Avg
2K
Both
10.5
11.8
11.7
Avg
3K
Both
14
14.7
13.4
Avg
4K
Both
16.5
17
17.4
Avg
6K
Both
22.8
23.5
20.3
Avg
8K
Both
19.8
22.5
21.9
Audiogram analysis
Average PLH Shift over Time
0.60
0.50
0.40
0.30
0.20
0.10
0.00
Total
2008
0.21
2009
0.54
2010
0.21
2011
0.28
2012
0.43
2013
0.50
Audiogram analysis
Average Noise Notch for HEGs
Workshop Engineering
Trackless
Roving Underground
Roving Surface
Ground Handling
0.00
Total
Ground Handling
11.75
2.00
4.00
Roving Surface
16.57
6.00
8.00
10.00
Roving Underground
10.59
12.00
Trackless
15.17
14.00
16.00
18.00
Workshop Engineering
14.82
Audiogram analysis
Average Noise notch Top 10 Occupations
TEAM LEADER
TIP ATTENDANT
ROCK DRILL OPERATOR
RDO
PTV
Not Specified
MINER
LHD OPERATOR
GENERAL WORKER
BELT ATTENDANT
0.00
BELT
GENERAL
ATTENDANT WORKER
Total
10.02
9.09
2.00
LHD
OPERATOR
13.41
4.00
6.00
8.00
10.00
12.00
MINER
Not Specified
PTV
RDO
17.40
11.65
10.45
13.82
14.00
16.00
18.00
ROCK DRILL
TIP
OPERATOR ATTENDANT
17.68
10.69
20.00
TEAM
LEADER
16.00
Audiogram analysis
Average PLH Shift Per HEG
0.60
35000
30000
0.50
25000
0.40
20000
0.30
15000
0.20
10000
0.10
0.00
Avg PLH
Record Count
5000
Ground
Handling
0.50
4724.00
Not Specified
0.31
30053.00
Roving
Surface
0.27
369.00
Roving
Underground
0.54
2261.00
Trackless
0.42
5259.00
Workshop
Engineering
0.25
180.00
0
Audiogram analysis
Average PLH Shift Per Occupation (Top 10)
TIP ATTENDANT
TEAM LEADER
ROCK DRILL OPERATOR
RDO
PTV
Not Specified
MINER
LHD OPERATOR
GENERAL WORKER
BELT ATTENDANT
-0.20
0.00
0.20
BELT
LHD
GENERAL
ATTENDA
OPERATO
WORKER
NT
R
Total
0.37
-0.01
0.66
0.40
0.60
0.80
1.00
MINER
Not
Specified
PTV
RDO
0.23
0.32
0.56
0.43
1.20
1.40
1.60
ROCK
DRILL
TEAM
OPERATO LEADER
R
1.66
0.61
1.80
TIP
ATTENDA
NT
0.33
Audiogram analysis
Average OHC damage measured per occupation (Top 10)
LHD
SUPERVISOR
BUILDER
SHIFT SUPERVISOR
TEAM LEADER
MILLWRIGHT
DRIVER
CRUSHER ATTENDANT
CONSTRUCTION ASSISTANT
STRATA CONTROL OFFICER
0.00
10.00
20.00
Record Count
30.00
40.00
50.00
60.00
Avg OHC Damage Index Both Ears
70.00
80.00
90.00
OAE analysis
Average OHC damage per HEG
250.00
200.00
150.00
100.00
Avg OHC Damage Index Both Ears
50.00
Record Count
17
33
Unknown
Roving Underground
15
Workshop Engineering
Ground Handling
13
Roving Surface
Trackless
0.00
Unknown
OAE analysis
Average OHC damage per HEG
250.00
200.00
150.00
100.00
Avg OHC Damage Index Both Ears
Record Count
50.00
17
33
Unknown
Roving Underground
15
Workshop Engineering
Ground Handling
13
Roving Surface
Trackless
0.00
Unknown
Coaching analysis
Had Noise Clipper Previously
32%
No
Yes
68%
Record Count
Had Noise Clipper Previously
- Over Time
1000
900
800
700
600
500
400
300
200
100
0
Yes
No
2011
9
84
2012
171
195
2013
215
711
Coaching analysis
Are you happy with HPD you
are using
31%
No
Yes
69%
Record Count
Are you happy with HP you are using - Over Time
200
180
160
140
120
100
80
60
40
20
0
8
9 10
2011
No 19 6
7
Yes 33 20 8
1
2
3
4
5
3
4
2
1
1
4
16
15
6
7
2012
68 9
40 6
8
9
10
11
12
31
1
11
37
27
64
1
8
17
1
2
3
4
5
6
2013
23 48 56 42 65 1
64 133 174 124 186 10
Audiogram analysis
Hearing Protection Types Used
0%
0%
Not Specified
7%
29%
None
17%
Ear Muffs
Disposable
Custom
47%
Other Custom
Record count
Hearing Protection Types Used
- Over Time
1000
900
800
700
600
500
400
300
200
100
0
Other Custom
Custom
Disposable
Ear Muffs
None
Not Specified
2011
4
29
54
6
2012
5
84
179
53
2
43
2013
308
448
119
51
Coaching analysis
Know noise levels in areas you
are working in
No
49%
51%
Yes
Know noise levels in areas you are working in
- Over Time
1000
900
Record count
800
700
600
500
400
300
200
100
0
Yes
No
2011
3
90
2012
106
260
2013
557
369
Coaching analysis
Exposed to noise during private
Activities
21%
No
79%
Yes
Otoscopic Examination Normal
15%
No
Yes
85%
Coaching analysis
Reason not wearing HPD
Suffer from ringing in the
ears
3%
13%
6%
Not Specified
35%
Uncomfortable
Not Necessary
No
Other Reason
Yes
65%
78%
Conclusion
There is currently insufficient evidence to be able to evaluate if
the proposed leading practice is indeed a leading practice for
the industry.
The audiogram stability is a good sign that it could be a
leading practice.
If the refinements are implemented and more data is available
for evaluation these practices have great potential to become
a leading practice for the industry.