Black Lung February, 2009 WV Coal Association Charleston, WV T M The findings and conclusions in this poster have not been formally disseminated by NIOSH and should not be construed to represent any agency determination or policy.
Jan 20, 2016
Black Lung
February, 2009
WV Coal Association
Charleston, WV
TM
The findings and conclusions in this poster have not been formally disseminated by NIOSH and should not be construed to represent any agency determination or policy.
50th wedding anniversary, 1971
My Maternal Grandfather
Died age 96
Coal miner in the Somerset
coalfield, England
Black Lung
• Collection of diseases– Pneumoconiosis– Chronic obstructive pulmonary disease– Emphysema
Pneumoconiosis
– Fibrotic diseases of the lungs caused by inhalation of dusts
– Coal workers’ pneumoconiosis (CWP), from coal mine dust
– Severe form is Progressive Massive Fibrosis (PMF)
– Silicosis, from silica dust– Both can lead to disability and premature
mortality– Very difficult to distinguish between them on
the x-ray
PMF‘Simple’ CWP
Progressive massive fibrosisComplicated pneumoconiosis
Normal
Pneumoconiosis is not caused by
smoking!…
Disease Prevention
• Primary disease prevention– Dust control– Alternatives– Ventilation– Respirators
• Secondary disease prevention– Early detection of disease and
reduction/elimination of further exposure
NIOSH coal miner programs
• NIOSH runs two related programs for worker monitoring for pneumoconiosis– Regular program – mine-based using clinics
to obtain x-rays– Enhanced program – community-based using
NIOSH mobile van
NIOSH coal miner programs
• Both programs have two major uses –– Secondary disease prevention through
entitlement to a low dust working environment if pneumoconiosis is seen
– Population surveillance data to monitor effectiveness of dust control, identify problems, and assess trends.
Secondary prevention
• May slow down or prevent severe disease development
• My grandfather left coal mining when pneumoconiosis was found
• However, those with simple pneumoconiosis are at greatly increased risk of severe disease, regardless of future dust exposure
• Secondary prevention reduces the likelihood of future severe disease but does not prevent its development
• Only adequate dust control prevents disease
National surveillance findings
CWP hot spot areas
CWP Hot Spot Areas
1970-1974
1975-1979
1980-1984
1985-1989
1990-1994
1995-1999
2000-2004
2005-2006*
Per
cen
tag
e
0
5
10
15
20
25
30
35
0-9 years10-14 years15-19 years 20-24 years25+ years
Tenure in Mining
Percent of miners with CWP by tenure in mining, 1970-1999
Percent of miners with CWP by tenure in mining, 1970-2006
1970-1974
1975-1979
1980-1984
1985-1989
1990-1994
1995-1999
2000-2004
2005-2006*
Per
cen
tag
e
0
5
10
15
20
25
30
35
0-9 years10-14 years15-19 years 20-24 years25+ years
Tenure in Mining
Number of miners with any CWP by age, 2000-2009
0
50
100
150
200
250
300
30 - 39 40 - 44 45 - 49
Age (years)
Nu
mb
er
Number of miners with severe CWP by age, 2000-2009
02468
1012141618
30 - 39 40 - 44 45 - 49
Age (years)
Nu
mb
er
Deaths with CWP, age 15-44, national data
0
5
10
15
20
25
30
1960 1970 1980 1990 2000 2010
Rising?
A recent death with severe CWP
Died age 6627 years as a coal miner
17 years underground
West Virginia
Mortality with CWP
CWP Mortality rates – highest counties in the nation
WV in 2008 – pneumoconiosis observed
• 1,517 coal miners examined in NIOSH program– Mean age = 47 years– Mean mining tenure = 22 years– 91 with any pneumoconiosis– 23 with PMF
WV in 2008 – expected
0102030405060708090
100
Any pneumoconiosis PMF
Observed
Expected: 1 mg/m3
~6 times ~15 times
Reasons for increase
• Longer hours worked?• Greater production?• Inadequate compliance for coal mine dust?• Increased exposure to silica dust?• Inadequate compliance method for silica?• (Dust limits are too high)
Reasons for increase
• Longer hours worked?• Greater production?• Inadequate compliance for coal mine dust?• Increased exposure to silica dust?• Inadequate compliance method for silica?• (Dust limits are too high)
Hours worked/year
hours/miner
1500
1700
1900
2100
2300
1975 1985 1995 2005
hours/miner
Data from MSHA website
Reasons for increase
• Longer hours worked?• Greater production?• Inadequate compliance for coal mine dust?• Increased exposure to silica dust?• Inadequate compliance method for silica?• (Dust limits are too high)
West Virginia coal employment and productivity
Miners
Productivity
Reasons for increase
• Longer hours worked?• Greater production?• Inadequate compliance for coal mine dust ?• Increased exposure to silica dust?• Inadequate compliance method for silica?• (Dust limits are too high)
WV coal mine dust levels
0
0.1
0.2
0.3
0.4
0.5
0.6
NorthWV
SouthWV
WestPA
EastKY
VA
1995-2003
All years
“Using two statistical approaches, data from three mining occupations in 54 large underground coal mines during 1976-1978 are examined for evidence of underreporting…Both approaches suggest widespread underreporting.”
0
0.5
1
1.5
2
1 -1415 - 24
25 - 34
35 - 49
50 - 74
75 - 124
125 - 224
225 - 334
335 - 999
Mine size
Du
st l
evel
(m
g/m
3)
Inspector Operator
MSHA Special Inspection survey, 1991
Reasons for increase
• Longer hours worked?• Greater production?• Inadequate compliance for coal mine dust?• Increased exposure to silica dust• Inadequate compliance method for silica?• (Dust limit are too high)
WV in 2008 – expected
0102030405060708090
100
Any pneumoconiosis PMF
Observed
Expected: 1 mg/m3
~6 times ~15 times
WV in 2008 – pneumoconiosis expected (3)
0102030405060708090
100
Anypneumoconiosis
PMF
Observed
Expected: 3.3 mg/m3
Implication
• Another factor apart from excessive coal mine dust exposure at work
• Preliminary findings from our program support the interpretation that the increase is partly due to an increase in silicosis
Historical evidence
Reasons for increase
• Longer hours worked?• Greater production?• Inadequate compliance for coal mine dust?• Increased exposure to silica dust?• Inadequate compliance method for silica?• (Dust limits are too high)
WV silica dust levels
0
0.01
0.02
0.03
0.04
0.05
0.06
NorthWV
SouthWV
WestPA
EastKY
VA
1995-2003
All years
“Although all of the analytical methods for crystalline free silica area sufficiently sensitive to be able to detect and quantitate free silica at environmentally significant concentrations, they
are all plagued with similar difficulties.”
Summary – What we know
• Prevalence of pneumoconiosis in miners with 20+ years of tenure x-rayed in the NIOSH monitoring program is rising
• Cases of severe disease continue to be seen in younger workers (<40 years old)
• Prevalence of pneumoconiosis far greater than expected from reported dust levels
Summary – What we are unsure about
• Exact cause of increase in prevalence and severity is not known
• Multiple causes may be at work– Longer hours worked– Inadequate compliance coupled with increased
productivity– Thin seam mining due to depletion of best coal
reserves, leading to excess silica exposure and silicosis
– Lack of knowledge/resources in small mines
Primary Solutions
• Modify compliance method for coal dust including use of personal dust monitor (being tested by NIOSH)
• More state assistance in county extension work for smaller mines?
• Adopt NIOSH recommended exposure limits for coal mine dust and silica levels
• Change compliance assessment method for silica dust (NIOSH recommendation)
Take Home Message
• Black Lung is entirely preventable using dust control
• No other prevention method (respirators, x-rays) can guarantee such success
• It behooves every employer and employee to minimize dust production
• Especial care is needed when rock is being cut
0
100
200
300
400
500
600
700
1 -1415 - 24
25 - 34
35 - 49
50 - 74
75 - 124
125 - 224
225 - 334
335 - 999
Mine size
Pro
du
ctio
n (
ton
s)
Inspector Operator
MSHA Special Inspection survey, 1991
Effect of coal rank
Effect of coal rank
Dust levels pre-1969 and in the early 1970s
WV silica levels in coal mines
NIOSH REL = 0.05 mg/m3
Dust levels in WV mines