Black Lung

1
Black Lung

• February, 2009
• WV Coal Association
• Charleston, WV

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.
2
My Maternal Grandfather
50th wedding anniversary, 1971
Died age 96
Coal miner in the Somerset coalfield, England
3
Black Lung

• Collection of diseases
• Pneumoconiosis
• Chronic obstructive pulmonary disease
• Emphysema

4
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

5
PMF
Normal
Simple CWP
Progressive massive fibrosis Complicated
pneumoconiosis
6
Pneumoconiosis is not caused by smoking!

7
Disease Prevention

• Primary disease prevention
• Dust control
• Alternatives
• Ventilation
• Respirators

• Secondary disease prevention
• Early detection of disease and reduction/eliminati
  on of further exposure

8
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

9
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.

10
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

11
National surveillance findings
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CWP hot spot areas
13
CWP Hot Spot Areas
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Percent of miners with CWP by tenure in mining,
1970-1999
15
Percent of miners with CWP by tenure in mining,
1970-2006
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Number of miners with any CWP by age, 2000-2009
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Number of miners with severe CWP by age, 2000-2009
18
Deaths with CWP, age 15-44, national data
Rising?
19
A recent death with severe CWP
Died age 66 27 years as a coal miner 17 years
underground
20
West Virginia
21
Mortality with CWP
22
CWP Mortality rates highest counties in the
nation
23
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

24
WV in 2008 expected
15 times
6 times
25
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)

26
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)

27
Hours worked/year
Data from MSHA website
28
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)

29
West Virginia coal employment and productivity
Productivity
Miners
30
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)

31
WV coal mine dust levels
32
Using two statistical approaches, data from
three mining occupations in 54 large underground
coal mines during 1976-1978 are examined for
evidence of underreportingBoth approaches
suggest widespread underreporting.
33
(No Transcript)
34
MSHA Special Inspection survey, 1991
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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)

36
WV in 2008 expected
15 times
6 times
37
WV in 2008 pneumoconiosis expected (3)
38
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

39
Historical evidence
40
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)

41
WV silica dust levels
42
(No Transcript)
43
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.
44
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 (lt40 years old)
• Prevalence of pneumoconiosis far greater than
  expected from reported dust levels

45
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

46
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)

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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

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MSHA Special Inspection survey, 1991
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Effect of coal rank
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Effect of coal rank
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Dust levels pre-1969 and in the early 1970s
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WV silica levels in coal mines
NIOSH REL 0.05 mg/m3
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Dust levels in WV mines