TABLE 8 (Cont'd.)

--- The expected total number of disabled workers is less than 25 and the PMR is not
significant at the .001 level.
* The difference between PMR and 100 is statistically significant at the .05 level.
*k The difference between PMR and 100 is statistically significant at the .01 level.
*%** The difference between PMR and 100 is statistically significant at the .001 level.

50


ulcer. The PMR's for diseases of the musculoskeletal system and
osteoarthritis were low but were not significant while that for displacement
of an intervertebral disc was high but not significant. The PMR for
accidents, poisoning, and violence was low but was not significant.

There were too few disability allowances for specific mining occupations
within the coal mining industry to permit analysis with the exception of other
mining occupations. Nevertheless, again a significant high PMR for
respiratory system cancer was found for blasters (DOT 931). Coal mining
industry employees working in other mining occupations (DOT 939) exhibited the
same disability pattern as those in all mining industries (Table 10).
Observed significance levels were not as great (higher Type I error
probability) for any cause of disability other than respiratory disease,
pneumoconioses, and pneumoconiosis due to silica and silicates. The PMR for
neoplasms was significantly low. The PMR for pneumoconiosis due to silica and
silicates for this occupation/industry was the highest for any considered.

The corresponding ratio of observed cases to expected was nearly 51.

In contrast to the coal mining industry, the distributicn of disabilities
among those employed in mining occupations (DOT 930-939) in the oil and gas
extraction industry (SIC 130-138) generally does not differ from the expected
(Table 11). Significant excesses of disabilities from musculoskeletal disease
and slipped disc were observed. It is interesting to note that no
disabilities from pneumoconiosis or silicosis occurred among men employed in
the oil and gas extraction industry. Moreover, there were no disabilities
caused by tuberculosis, bronchitis, or asthma. The PMR for accidents,
poisoning, and violence was high but was not significant. Men employed in
boring, drilling, cutting, and related occupations (DOT 930) had excess
disability from musculoskeletal disease (Table 12). The small number of
disability allowances in the other occupational groups precludes precise
statistical analysis.

The proportion of disabilities from diseases of the respiratory system was
significantly high for men employed in all mining occupations (DOT 930-939) in
the metal and nonmetallic nonfuel mineral industry (SIC 100-209, 140-149)
(Table 13). Individual occupational groups were not examined because of the
small sample size.

The results of analysis by industry and occupation for 1975-76 are summarized
in the table below. Respiratory system diseases and diseases of the
musculoskeletal system and connective tissue were the primary causes of excess
disability among miners in all mining industries. Pneumoconiosis, bronchitis
and asthma, and emphysema caused the excess respiratory disease disability.
Displacement of intervertebral disc and osteoarthritis contributed most to the
excess in disability from diseases of the musculoskeletal system and
connective tissue. For all mining industries except oil and gas extraction,
statistically significant excess disability was caused by diseases of the
respiratory system. Statistically significant excess disability among
employees in the oil and gas extraction industry was due to diseases of the
musculoskeletal system and connective tissue. Industry, not occupation, was
associated with variation in cause of major disability.

-16-


Causes of Disability in Employees of the Mining Industry:
Analysis of Social Security Disability Benefit Awards
And Allowances to Workers
1969-1973, 1975-1976

Rebecca Osborne and Thomas Fischbach

Illness Effects Section, Surveillance Branch
Division of Surveillance, Hazard Evaluations and Field Studies
National Institute for Occupational Safety and Health
Cincinnati, Ohio

U.S. DEPARTMENT OF HEALTH AND HUMAN SERVICES
Public Health Service
Centers for Disease Control
National Institute for Occupational Safety and Health
Division of Surveillance, Hazard Evaluations and Field Studies
Cincinnati, Ohio 45226

April 1985


TABLE 13: Estimated number and age-adjusted proportional morbidity ratios,
PMR, and standard errors, (S.E. (PMR), for white males employed in
extraction of minerals (DOT 930-939) in metal mining and
nonmetallic minerals (SIC 100-109, 140-149) by disabling
condition: Social Security Disability Allowances, 1975-1976.

1975-1976
ICDA PMR SE(PMR) TOTAL
All disabling conditions 412
Infective & parasitic diseases 000-136 1
Tuberculosis 010-019 1
Pulmonary tuberculosis 011 — 1
Neoplasms 140-239 102 42 40
Malignant neoplasms 140-199 84 47 28
Respiratory system 160-163 — 13
Bone, connective tissue, &
skin 170-173 > 2
Urinary organs 188-189 al 4
Other & unspecified sites 190-199 =— 9
Neoplasms of lymphatic &
hematopoietic tissue 200-209 a 10
Leukemia 204-207 10
Neoplasms of unspecified nature 230-239 aS 2
Mental disorders 290-315 46 25 16
Schizophrenia 295 as 6
Diseases of nervous system & sense
organs 320-389 _ 12
Multiple sclerosis 340 -_- 4
Glaucoma 375 > 6
Diseases of circulatory system 390-458 79 20 107
Heart & hypertensive disease 393-429 65 17 70
Hypertensive disease 400-404 _ 7
Ischemic heart disease 410-414 65 17 61
Cerebrovascular disease 430-438 — 20
Cerebral thrombosis & embolism 433-434 — 7
Arteriosclerosis 440 — 10
Diseases of respiratory system 460-519 337 * 75 108
Emphysema 492 — 32
Pneumoconiosis & related
diseases 515-516 —> 30
Pneumoconiosis due to
silica & silicates 515 ——o 30

59


Diseases of nervous system
& sense organs
Multiple sclerosis
Cataract
Glaucoma
Blindness

Diseases of circulatory

system

Heart & hypertensive
disease
Hypertensive disease
Ischemic heart disease

Cerebrovascular disease
Cerebral thrombosis &

embolism

Arteriosclerosis

Diseases of digestive system
Peptic ulcer
Chronic enteritis &
ulcerative colitis
Cirrhosis of liver

Diseases of genitourinary

system

Nephritis & nephrosis
Chronic nephritis

Other diseases of urinary
system

Diseases of male genital
organs

Diseases of skin & sub-
cutaneous tissue

Diseases of musculoskeletal
system & connective tissue
Rheumatoid arthritis
Osteoarthritis
Other & unspecified

arthritis
Displacement of inter-
vertebral disc

TABLE A-4 (Cont'd.)

ICDA

320-389
340
374
375
379

390-458
393-429
400-404
410-414
430-438

433-434
440

520-577
531-533

563
571

580-629
580-584
582

590-599

600-607

680-709

710-738

1969-1973
PMR SE(PMR) TOTAL

79 #KK
28 *
142

96

96
103
139

101
45 RK

69
122

79 *k
167

81
48
57

105

119

134 #e*
168 ***
154

131 *

70

5
23

30

Nv
NERS

29
28

23
36

48

45

5
14
11
45

14

503
15
34
19
32
3693
3045
141
2651

236

80
182

260
86

63
19
19
34

10

41

2133
186
862
102

554

1975-1976

PMR SE(PMR) TOTAL

100

104
102
107
100

116

157
97
171

193

15

7
8
33
9
24
48

21

31

ake OQ

33
29

zk 26

161
4
10
1
14

1027
861
42
774
112

26
36

102
33

20

833
45
292
28

253


934 Screening
939 Mining, not elsewhere classified (N.E.C.)

The definitions of these occupations have been published (U.S. Department of
Labor, 1965) and are summarized as follows. The boring, drilling, and cutting
group includes occupations concerned with drilling wells, undercutting coal
seams, sawing and splitting virgin rock, and related activities involved with
tapping water-or mineral-bearing formations, obtaining samples of sub-surface
strata, and loosening or removing materials. Blasting occupations are
concerned with preparation, placement, and detonation of explosives to
shatter, dislodge, or move earth, coal, and ore-bearing materials in surface
and underground mines and quarries. Loading and conveying occupations involve
moving workers, equipment, and extracted materials. Crushing occupations
reduce bulky materials to convenient sizes using sledge hammers and crushing
machines. The screening occupational group cleans, separates, and sizes coal,
ore, stone, and similar materials. Occupations in mining, n.e.c. include
miner, pit supervisor, oil well service operator, and roustabout.

Industry refers to the industry of the longest employment of the disabled
worker in the 10 years preceding disability. Industry, which was available
only for 1975-76, was coded using the Standard Industrial Classification (SIC)
(Executive Office of the President, 1972). In this report mining, SIC
100-149, and certain subsets of the mining industry were compared to all other
industries combined. Bituminous, lignite, and anthracite coal mining was
classified under SIC 110-121. Oil and gas extraction was classified under SIC
130-138. Metal mining (SIC 100-109) includes mining of iron, copper, lead,
zinc, gold, silver, uranium and aluminum. Nonmetallic mineral mining (SIC
140-149) includes stone, sand, gravel, clay, and granite. In this study,
metal mining and nonmetallic mineral mining were combined because there were
not sufficient cases for more detail. By combining industry and occupation
codes it was possible to study specifically those workers most exposed to the
hazards of mining. The analyses for 1975-76 were thus restricted to those
employees of the mining industry, i.e., SIC codes 100-149, who worked in
mining occupations, i.e., DOT codes 930-939.

The Social Security Disability Benefit Program

Social security disability beriefits are available to qualified totally
disabled workers regardless of the cause of their impairments; it is not
necessary for the disability to be occupationally caused. To qualify for
benefits, workers disabled after age 30 must have worked in covered employment
for at least 5 of the 10 years immediately preceding the onset of disability;
progressively fewer years of coverage are required for younger workers. To be
eligible, a worker must be unable to engage in any substantial gainful
activity because of a medically determinable physical or mental impairment
that has lasted or can be expected to last for at least 12 months or to result
in death (SSA, 1982).


TABLE A-2 (Cont'd.)

1969-1973 1975-1976
ICDA PMR SE(PMR) TOTAL PMR SE(PMR) TOTAL

Diseases of nervous system &

sense organs 320-389 56 *** 10 159 94 17 90
Multiple sclerosis 340 — 15
Cataract 374 275 128 250 --= 2
Glaucoma 375 a 5
Blindness 379 — ll --- 12
Diseases of circulatory
system 390-458 80 *** 4 1158 93 9 437
Heart & hypertensive
disease 393-429 187 * 26 941 95 12 357
Hypertensive disease 400-404 108 22 420 --- 36
Ischemic heart disease 410-414 85 * 5 839 91 13 296
Cerebrovascular disease 430-438 49 *RR 17 98 63 36 32
Cerebral thrombosis &
embolism 433-434 55 29 24 --~ 7
Arteriosclerosis 440 55 34 30 --- 20
Diseases of digestive system 520-577 61 * 16 82 133 46 57
Peptic ulcer 531-533 -~- 5-— 20
Chronic enteritis &
ulcerative colitis 531-533 => 2
Cirrhosis of liver 571 —> 28
Diseases of genitourinary
system 580-629 59 30 21 25
Nephritis & nephrosis 580-584 ~-- 7 25
Chronic nephritis 582 -_— 7-- 25
Other diseases of urinary
system 590-599 --- 10
Diseases of male genital
organs 600-607 —-~ 4

Diseases of skin & sub-
cutaneous tissue 680-709 191 101 28

Diseases of musculoskeletal
system & connective tissue 710-738 163 *** 13 1088 176 *** 45 444

Rheumatoid arthritis 712 78 22 66 14 eee 7 3
Osteoarthritis 713 210 ** 27 396 174% 32 136
Other & unspecified 710-711,

arthritis 714-715 112 39 29 --~ 9
Displacement of inter-

vertebral disc 725 190 ** 27 375 261 ** 46 168

65


determine if this incidence is increasing; 3) Continue studies of the mining
industry to determine methods to control respiratory disease; 4) Conduct
studies to determine the causes of the high relative incidence of emphysema
and its prevention; 5) Also, conduct studies to determine the causes of the
high relative incidence of diseases of the musculoskeletal system and
connective tissue and their prevention especially in the oil and gas
extraction industries; and 6) Study the causes of injuries in the mining
industry which remain a source of disability for relatively large numbers of
miners and also measure the relative incidencies of disabilities from
accidents, from poisoning, and from violence separately.

23


TABLE 1 (Cont'd.)

Diseases of digestive system
Peptic ulcer
Chronic enteritis & ulcerative colitis
Cirrhosis of liver
Diseases of genitourinary system
Nephritis & nephrosis
Chronic nephritis
Other diseases of urinary system
Diseases of male genital organs
Diseases of skin & subcutaneous tissue
Diseases of musculoskeletal system & connective tissue
Rheumatoid arthritis
Osteoarthritis
Other & unspecified arthritis
Displacement of intervertebral disc
Congenital anomalies
Symptoms & ill-defined conditions
Accidents, poisonings, & violence
Unknown or not classifiable

30

510-577
531-533
563

571
580-629
580-584
582
590-599
600-607
680-709
710-738
712

713
710-711, 714-715
725
740-759
780-796
800-999


TABLE 11: Estimated number and age-adjusted proportional morbidity ratios,
PMR, and standard errors, S.E. (PMR), for white males employed in
extraction of minerals (DOT 930-939) in oil and gas extraction

Social Security

industries (SIC 130-138) by disabling condition:
Allowances, 1975-1976

All disabling conditions

Neoplasms
Malignant neoplasms
Respiratory system
Genital organs
Neoplasms of lymphatic &
hematopoietic tissue

Endocrine, nutritional, &
metabolic diseases
Diabetes mellitus

Mental disorders
Schizophrenia
Neuroses

Diseases of nervous system &
sense organs
Multiple sclerosis
Blindness

Diseases of circulatory system
Heart & hypertensive disease
Ischemic heart disease
Cerebrovascular disease
Arteriosclerosis

Diseases of respiratory system
Emphysema

Diseases of digestive system
Chronic enteritis &
ulcerative colitis
Cirrhosis of liver

Diseases of musculoskeletal
system & connective tissue
Osteoarthritis
Displacement of inter-

vertebral disc

140-239
140-199
160-163
180-187

200-209

240-279
250

290-315
295
300

320-389
340
379

390-458
393-429
410-414
430-438
440

460-519
492

520-577
563
571
710-738
713

725

55

187
205

424

1975-1976
SE(PMR)

28
60

41

19
18

32

33
69

102

TOTAL
666
34
25
21
4
9

12
12

59
10
14
215
170
168
10

40
17

22

201
71

113


Lumio, J.S. 1965. Noise and Hearing Ability. Industry hly 96:709-711.

Liddell, F.D.K. 1973. Morbidity of British Coal Miners in 1961-1962. Brit J
Industry Med 30(1):1-14.
Med Surg 34:404-406.

Lundin, F.E. Jr., J.W. Lloyd, E.M. Smith, V.E. Archer, D.A. Holaday. 1969,
Mortality of Uranium Miners in Relation to Radiation Exposure, Hard-rock
Mining, and Cigarette Smoking - 1950 through September 1967. Health Physics
16:571-578.

Milham, S. 1983. Occupational Mortality in Washington State 1950-1979. DHHS
(NIOSH) Publication No. 83-116.

Morgan, W.K.C., D.B. Burgess, G. Jacobson, R.J. O'Brien, E.P. Pendergrass,
R.B. Reger, and E.P. Shoub, 1973. The Prevalence of Coal Workers’
Pneumoconiosis in U.S. Coal Miners. Arch Env Health 27:227-230.

Naeye, R.L. 1970 Soft Coal Workers’ Pneumoconiosis, a Quantitative,
Postmortem Study. In: Papers and Proceedings of the National Conference on
Medicine and the Federal Coal Mine Health and Safety Act of 1969. pp. 98-100,
Washington, D.C.

NIOSH, 1976. Survey of Hearing Loss in the Coal Mining Industry. Public
Health Service, U.S. Dept of HEW, Cincinnati, Ohio.

Parsons, W.D., A.J. deVillers, L.S. Bartlett, and M.R. Becklake. 1964. Lung
Cancer in a Fluorspar Mining Community II. Prevalence of Respiratory
SymptoMed 21:110-116.

Popick, Bernard. 1971. “The Social Security Disability

Program: 1. Characteristics of the Program", Journal of Occupational
Medicine, Vol. 13, No. 5.

Popick, Bernard. 1971. "The Social Security Disability Program: 2. Medical
Evaluation of Claims, “Journal of Occupational Medicine, Vol. 13, No. 6.

Popick, Bernard. 1971. “The Social Security Disability Program: 3. Black
Lung Benefits - in Administrative Study”, Journal of Occupational Medicine,
Vol. 13, No. 7.

Public Health Service. 1967. Occupational Characteristics of Disabled
Workers, by Disabling Condition: Disability Insurance Benefit Awards Made in
1959-1962 to Men Under Age 65. Public Health Publication No. 1531.

Ranasinha, K.W. and C.G. Uragoda. 1972. Graphite Pneumoccniosis. Brit J
Industry Med 29:178-183.

Registrar General. 1957. Decennial Supplement, England and Wales, 1951:
Occupational Mortality Tables. Her Majesty's Stationery Office, London.

Registrar General. 1971. Decennial Supplement, England and Wales, 1969:
Occupational Mortality Tables. Her Majesty's Stationery Office, London.

26


TABLE 12 (Cont'd.)

1975-1976
ICDA PMR SE(PMR) TOTAL
Accidents, poisonings, & violence 800-999 140 44 40
Unknown or not classifiable — 1

--- The expected total number of disabled workers is less than 25 and the PMR is not
significant at the .001 level.
* The difference between PMR and 100 is statistically significant at the .05 level.
** The difference between PMR and 100 is statistically significant at the .01 level.
**k The difference between PMR and 100 is statistically significant at the .001 level.

58


TABLE 3 (Cont'd.)

1969-1973 1975-1976
Diseases of skin & sub- Hens Pug SE(PMR) TOTAL PMR SE(PMR) TOTAL

cutaneous tissue 680-709 163 97 28

Disease of musculoskeletal
system & connective tissue 710-738 138 ** 9 1088 151 * 18 444
&)

Rheumatoid arthritis 712 66 16 66 12 *** 12
Osteoarthritis 713 172 *** 16 396 147 21 (136
Other & unspecified 710-711,
arthritis 714-715 94 37 29 — 9
Displacement of inter-
vertebral disc 725 166 29° 375 227 * 43° 168
Congenital anomalies 740-759 = 81 21 45 — 17

Symptoms & ill-defined
conditions 780-796 — 10

Accidents, poisonings, &
violence 800-999 187 *** 17 867 126 23, 137

-~- The expected total number of disabled workers is less than 25 and the PMR is not
significant at the .001 level.
* The difference between PMR and 100 is statistically significant at the .05 level.
*k The difference between PMR and 100 is statistically significant at the .01 level.
*** The difference between PMR and 100 is statistically significant at the .001 level.

36


TABLE A-8: Estimated number and age-adjusted proportional morbidity ratios,
PMR, and standard errors, S.E. (PMR), for white males employed in
extraction of minerals (DOT 930-939) in bituminous, lignite, and
anthracite coal mining (SIC 110-121) by disabling condition
other than respiratory: Social Security Disability Awards,

1975-1976.
1975-1976
ICDA PMR SE(PMR) TOTAL
All disabling conditions 1574
Infective & parasitic diseases 000-136 — 5
Neoplasms 140-239 62 17 100
Malignant neoplasms 140-199 66 20 90
Digestive organs & peritoneum 150-159 55 43 17
Respiratory system 160-163 53 26 27
Genital organs 180-187 20
Urinary organs 188-189 5
Other & unspecified sites 190-199 — 21
Neoplasms of lymphatic &
hematopoietic tissue 200-209 a) 10
Endocrine, nutritional, &
metabolic diseases 240-279 26 ** 22 14
Diabetes mellitus 250 10 *** il 4
Diseases of blood & blood-
forming organs 280-289 — 10
Mental disorders 290-315 122 14 187
Schizophrenia 295 68 27 36
Neuroses 300 294 ** 57 95
Alcoholism 303 => 6
Diseases of nervous system &
sense organs 320-389 69 15 67
Cataract 374 — 10
Blindness 379 — 10
Diseases of circulatory system 390-458 107 9 590
Heart & hypertensive disease 393-429 123 11 541
Hypertensive disease 400-404 —= 41
Ischemic heart disease 410-414 123 12 473
Cerebrovascular disease 430-438 40 28 24
Cerebral thrombosis & embolism 433-434 oS 10
Arteriosclerosis 440 = 15

78


INTRODUCTION

Through an interagency agreement the National Institute for Occupational
Safety and Health (NIOSH) has acquired data on the characteristics of workers
receiving benefit awards for disabilities from the Social Security
Administration (SSA). Such awards are granted to workers with social security
eligibility who have physical or mental impairments so severe that they are
unable to engage in any substantial gainful employment. SSA collects data
from applicants as part of its routine administration of the disability
program. Data from a sample of the workers actually receiving benefit awards
are coded and placed in a computer accessible data file. The NIOSH file is a
subset of this file. This data file provides a unique resource for NIOSH to
conduct occupational health research including surveillance of adverse health
effects. This surveillance encompasses two objectives: (1) To monitor known
or suspected patterns of disability to determine if there have been changes;
and (2) To detect patterns of disability that either have been undetected in
the past or which are emergent.

The purpose of this report is surveillance of the patterns of disability of-
persons employed in the mining industry and in mining occupations. This is
part of a larger effort to prevent morbidity and mortality to workers in
mining industries and occupations. Monitoring previously recognized or
suspected patterns permits evaluation of intervention efforts. It also tests
current hypotheses. The detection of previously unrecognized or of emergent
patterns of morbidity is necessary so that additional research can lead to
successful intervention.

Previous research was reviewed to determine expected patterns of disability
for workers in mining industries and occupations. Little previous work has
been done directly on the question of disabilities to miners. However, there
is a large body of research on the mortality and, to a lesser extent, the
morbidity of miners. For the purpose of generating hypotheses for this
analysis, it is assumed that, unless there are known exceptions, conditions
which produce mortality or morbidity will also increase the risk of impairment
serious enough to produce disability. Causes of the morbidity or mortality
are related to specific mining industries or mining occupations when such
information is available. The results of this review are summarized in the
next section.

The review was not limited by consideration of whether the NIOSH-SSA
disability data file would support an investigation of the'findings of other
researchers. However, the development of specific surveillance hypotheses to
guide this analysis required consideration of both the resources and
limitations of the NIOSH-SSA disability data file. These are discussed in the
Materials and Methods Section. The Surveillance Hypotheses Section then
describes the specific surveillance hypotheses guiding the analysis and the
specific methods for testing these. The results of the analysis are presented
in the Results section. These results are discussed and recommendations for
the future are presented in the Discussion Section.


ABSTRACT

This study examined the causes of disability for Social Security
Administration disability benefit awards and allowances to white male miners
for 1969-73 and 1975-76. Age-adjusted proportional morbidity ratios (PMR's)
were calculated for 67 causes of disability for six mining occupations and
four mining industries. Significantly high PMR's were found for diseases of
the respiratory system as causes of disability among all groups except the oil
and gas extraction industry. Musculoskeletal diseases caused
disproportionately high disability among employees of the oil and gas
extraction industry. PMR's were recalculated excluding diseases of the
respiratory system since the very high association between these diseases and
mining could obscure other associations. After removing disabilities from
respiratory diseases from the data, the PMR's for accidents, poisonings, and
violence and musculoskeletal disease were significantly high. These results
agreed with those of previous morbidity and mortality studies and illustrate
the utility of routinely collected disability data as a surveillance tool in
occupational disease and injury epidemiology.

iv


TABLE 2 (Cont'd.)
1969-1973 1975-1976
ICDA PMR SE(PMR) TOTAL PMR SE(PMR) TOTAL

Disease of musculoskeletal
system & connective

tissue 710-738 106 3 3652 123 * 7 1453
Rheumatoid arthritis 712 69 *eK 5 313 46 *k 14 48
Osteoarthritis 713 123 ** 7 1377 128 16 498
Other & unspecified 710-711,
arthritis 714-715 115 18 167 79 34 39
Displacement of inter-
vertebral disc 725 117 9 1062 162 ** 17 464
Congenital anomalies 740-759 67 * 14 145 49* 17 34
Symptoms & ill-defined 780-796 -~- 14 — 10
conditions

Accidents, poisonings, &
violence 800-999 139 *** 6 2318 118 13 459

—-- The expected total number of disabled workers is less than 25 and the PMR is not
significant at the .001 level.
* The difference between PMR and 100 is statistically significant at the .05 level.
** The difference between PMR and 100 is statistically significant at the .01 level.
*kk The difference between PMR and 100 is statistically significant at the .001 level.

33


Table A~2: Estimated number and age-adjusted proportional morbidity ratios,
PMR, and standard errors, S.E. (PMR), for white males employed in
boring, drilling, cutting, and related occupations (DOT 930) by
disabling condition other than respiratory: Social Security
Disability Awards, 1969-1973, and Allowances, 1975-1976.

1969-1973 1975-1976
ICDA PMR SE(PMR) TOTAL PMR SE(PMR) TOTAL
All disabling conditions 4242 1457
Infective and parasitic
diseases 000-136 123 29° 109
Tuberculosis 010-019 150 42 91
Silicotuberculosis 010 — 8
Pulmonary tuberculosis 011 156 49 82
Neoplasms 140-239 72 %* 9 312 71 17 101
Malignant neoplasms 140-199 73% 9 263 106 21 78
Buccal cavity & pharynx 140-149 --- 17
Digestive organs &

peritoneum 150-159 75 18 61 8 RRR 6 2
Respiratory system 160-163 73 * 12 97 93 35 40
Bone, connective tissue,

& skin 170-173 --- 10 —- 10
Genital organs 180-187 --- llo--- 26
Urinary organs 188-189 --- 22
Other & unspecified

sites 190-199 78 26 45

Neoplasms of lymphatic &
hematopoietic tissue 200-209 78 31 49 -— 19

Sarcoma (lympho-,
reticulo-), other

lymphomas 200,202 --- 10
Leukemia 204-207. --- 21 --- 5
Benign neoplasms 210-228 --- 2
Neoplasms of unspecified
nature 230-239 _- 2
Endocrine, nutritional, &
metabolic diseases 240-279 59 * 16 83 23 eR IT 11
Diabetes mellitus 250 58 20 61 24 *eR O14 9
Diseases of blood & blood-
forming organs 280-289 --~ 9
Mental disorders 290-315 56 *** 8 281 75 21 127
Schizophrenia 295 36 RRR 8B 78 74 37 51
Neuroses 300 93 25 75 137 40 42
Alcoholism 303 34 ** 618 9

64


TABLE A-5 (Cont'd.)

1975-1976
ICDA PMR SE (PMR) TOTAL
Hypertensive disease 400-404 163 38 90
Ischemic heart disease 410-414 105 7 1018
Cerebrovascular disease 430-438 86 18 129
Cerebral thrombosis & embolism 433-434 110 70 28
Arteriosclerosis 440 169 41 71
Diseases of digestive system 520-577 117 22 144
Peptic ulcer 531-533 — 53
Chronic enteritis &
ulcerative colitis 563 — 8
Cirrhosis of liver 571 85 31 52
Diseases of genitourinary system 580-629 47 38
Nephritis & nephrosis 580-584 23
Chronic nephritis 582 23
Cther diseases of urinary system 590-599 — 15
Diseases of skin & sub~
cutaneous tissue 680-709 — 20
Diseases of musculoskeletal
system & connective tissue 710-738 160 *** 10 1136
Rheumatoid arthritis 712 56 21 35
Osteoarthritis 713 173 * 26 397
Other & unspecified arthritis 710-711,
714-715 134 53 39
Displacement of intervertebral
disc 725 21] #*% 24 369
Congenital anomalies 740-759 77 24 33
Accidents, poisonings, & violence 800-999 143 * 18 342
Unknown or not classifiable —5 3

--- The expected total number of disabled workers is less than 25 and the PMR is not
significant at the .001 level.
* The difference between PMR and 100 is statistically significant at the .05 level.
** The difference between PMR and 100 is statistically significant at the .01 level.
**k The difference between PMR and 100 is statistically significant at the .001 level.

73


RESEARCH REPORT

Causes of Disability in Employees
of the Mining Industry :

Analysis of Social Security Disability
Benefit Awards and Allowances
to Workers: 1969-1973, 1975-1976

U.S. DEPARTMENT OF HEALTH AND HUMAN SERVICES
Public Health Service

Centers for Disease Control

National Institute for Occupational Safety and Health



PREFACE

The Social Security Administration (SSA) routinely collects data. on workers
eligible for benefits for total disability. Both SSA and the National
Institute for Occupational Safety and Health (NIOSH) recognize these data as
an inexpensive resource for occupational health and safety research aimed at
preventing diseases and accidents that result in injury, illness, disability
and death. This surveillance report about the mining industry is one product
of the collaboration of SSA and NIOSH using the disabled worker data base.

iii


in other mining industries, while in the oil and gas extraction industry,
musculoskeletal and connective tissue disease was the leading cause of
disability. No employee of the oil and gas extraction industry was awarded
disability for pneumoconiosis. This difference in the disability patterns
most likely illustrates the importance of exposure to dusts resulting from
mining activities in the development of pneumoconiosis. These data do not
contain information by type of mine (surface or underground); it was not
possible to determine if the lower prevalence of pneumoconiosis in surface
miners reported in the literature was reflected in fewer disability awards for
pneumoconiosis.

The lack of relationship of musculoskeletal disease to coal mining and metal
and nonmetallic mining, in contrast to the significant relationships of these
causes of disability to the oil and gas extraction industry, may be a
compensation for the huge PMR's for respiratory diseases. This is suggested
by the results of the re-analysis of the data after all awards or allowances
for respiratory system diseases were deleted. High PMR's for musculoskeletal
diseases were found for most mining industries even coal mining.

Variations among occupations within the same industry do not appear as
important as variations among industries for the same occupation for
differences in distributions ef conditions causing disabilities.

This study examines only the primary cause of disability. Thus, increases in
disability from diseases associated with pneumoconiosis, such as cor pulmonale
and rheumatoid arthritis, might not be detected. Competing causes of
disability could not be examined to determine if certain patterns of
disability occurred together.

Accidents appear to be a disproportionate source of disabilities for workers
in mining occupations and in mining industries in both periods, especially
when the depressing effects of the huge PMR's for respiratory diseases are
removed. These results may underestimate the true impact of accidents as
sources of major chronic impairment for mine workers. Many mine accidents may
be clearly occupational so that the worker's claim for worker's compensation
is readily established. While worker's compensation awards do not preclude
SSA disability awards in all cases, in some cases the benefit “offset” may be
enough to do so. However, worker's compensation awards certainly do not
preclude allowances. In addition, some workers receiving worker's
compensation awards may mistakingly believe that they have exhausted their
sources of benefits and may not apply for SSA benefits.

Malignant neoplasms of the respiratory system and the digestive system were
hypothesized as causes of disproportionately high disability but were found,
instead, to cause disproportionately low numbers of disabilities (with the
single exception of the high respiratory cancer PMR for coal mine blasters for
1975-76). This result is puzzling not only because of the previously cited
evidence that miners may engage in heavier smoking than other workers, but
also because underground workers have often been considered at higher risk
for lung cancer. In part, this finding may reflect the oft-mentioned

21


TABLE A~9: Estimated number and age-adjusted proportional morbidity ratios,
PMR, and standard errors, S.E. (PMR), for white males employed
in occupations in the extraction of minerals, n.e.c. (DOT 939) in
bituminous, lignite, and anthracite coal mining (SIC 110-121) by
disabling conditions other than respiratory: Social Security
Disability Allowances, 1975-1976.

1975-1976
ICDA PMR SE(PMR) TOTAL
All disabling conditions 1102
Infective & parasitic diseases 000-136 _— 5
Neoplasms 140-239 46 ** 14 52
Malignant neoplasms 140-199 54 * 17 52
Digestive organs & peritoneum 150-159 = 5
Respiratory system 160-163 44 * 20 16
Genital organs 180-187 => 5
Urinary organs 188-189 _ 5
Other & unspecified sites 190-199 ad 21
Endocrine, nutritional, &
metabolic diseases 240-279 38 31 14
Diabetes mellitus 250 14 *** 13 4
Mental disorders 290-315 119 16 127
Schizophrenia 295 44 Re 15 16
Neuroses 300 — 65
Alcoholism 303 _ 6
Diseases of nervous system &
sense organs 320-389 67 18 46
Cataract 374 — 10
Diseases of circulatory system 390-458 111 11 428
Heart & hypertensive disease 393-429 125 14 384
Hypertensive disease 400-404 eal 26
Ischemic heart disease 410-414 124 14 336
Cerebrovascular disease 430-438 57 37 24
Cerebral thrombosis & embolism 433-434 — 10
Arteriosclerosis 440 ae als
Diseases of digestive system 520-577 157 49 53
Peptic ulcer 531-533 a> 20
Cirrhosis of liver 571 _ 18
Diseases of genitourinary system 580-629 — 11
Nephritis & nephrosis 580-584 6
Chronic nephritis 582 — 6
5

Other diseases of urinary system 590-599 -_

80


TABLE A~6 (Cont'd.)

1975-1976
ICDA PMR SE(PMR) TOTAL
Diseases of musculoskeletal
system & connective tissue 710-738 160 * 25 248
Osteoarthritis 713 177 41 88
Other & unspecified arthritis 710-711,
714-715 > 9
Displacement of intervertebral
disc 725 254 * 62 98
Congenital anomalies 740-759 = 16
Accidents, poisonings, & violence 800-999 115 72 65
Unknown or not classifiable — 1

--- The expected total number of disabled workers is less than 25 and the PMR is not
significant at the .001 level.
* The difference between PMR and 100 is statistically significant at the .05 level.
*k The difference between PMR and 100 is statistically significant at the .01 level.
**k The difference between PMR and 100 is statistically significant at the .001 level.

75


High mortality in Swedish iron ore miners was reported by Jorgensen (1973) and
St. Clair Renard (1974). In a nationwide mortality study, the average lung
cancer mortality among Swedish miners (the majority mining iron ore) was five
times that of the general population. A dose-response relationship between
lung cancer mortality and the concentration of radon daughters was noted
(Axelson and Sundell, 1978). Excess lung cancer mortality was observed in
British (Boyd et al., 1970) and American iron ore miners (Edling, 1982) and in
fluorspar miners (Parsons et al., 1964; deVillers and Windish, 1964). Smokers
were consistently at excess risk compared to nonsmoking fluorspar miners.

Silicosis, a chronic dust disease of the lung (pneumoconiosis) caused by
pulmonary retention of particulate silica, became common among miners at the
turn of the century due to increased mechanization and the development of
pneumatic tools that generated large amounts of dust. A positive relationship
was demonstrated between the concentration of dust and silicosis incidence
(Iannssen, 1971). Victims usually have at least 15 years mining experience
(Key and Ayer, 1972). Ina study of silicosis and occupation, miners had the
shortest median exposure time before disease onset and the most rapid
radiological progression of all occupations studied (Ahlman, 1968). Silicotic
nodules were present in the lungs of 44 percent of the bituminous miners
studied by Naeye (1970).

The prevalence of black lung disease, another form of pneumoconiosis, varies
greatly between geographic areas, from 7 percent to 46 percent in working
underground miners (Higgins et al., 1968; Lapp, 1969; Morgan et al., 1972).
The prevalence of pneumoconiosis was also associated with dust exposure in a
20 year cohort study of 10 British coal mines (Hurley et al., 1982). Among
men with similar cumulative dust exposures, those with longer exposure times
had a higher prevalence of pneumoconiosis. Pneumoconiosis is not restricted
to the coal mining industry; it has been reported in gold miners (Solomon,
1977) and in graphite miners (Ranasinha and Uragoda, 1972).

Surface coal miners appear to experience a low prevalence of pneumoconiosis
(4 percent) (Fairman et al., 1977). Of surface miners who had never worked
underground, only 2.5 percent had pneumoconiosis. The prevalence of
pneumoconiosis in surface miners with extensive underground experience was
11.2 percent. However, the total mining experience of the two groups of
miners were not compared. The total mining experience of the former
underground miners may have been longer which might have caused the difference
or the difference might be caused by other factors, e.g. selection, etc.

Thus, while the prevalence of pneumoconiosis may be much greater in
underground than in surface miners, the evidence is not clear.

In addition to greater prevalence of silicosis and other forms of
pneumoconiosis and higher lung cancer mortality, workers in the mining
industry experience greater prevalence of chronic respiratory disease. Loss
of ventilatory capacity increased in British coal miners with increasing dust
exposure in all age-smoking groups (Rogan et al., 1973). Coal miners had more
wheezing, dyspnea, and history of pneumonia and pleurisy than other manual
nonmining workers (Enterline and Lainhart, 1967). Welsh miners had a higher


ak
RK

TABLE 6 (Cont'd.)

The expected total number of disabled workers is less than 25 and the PMR is not
significant at the .001 level.

The difference between PMR and 100 is statistically significant at the .05 level.
The difference between PMR and 100 is statistically significant at the .01 level.
The difference between PMR and 100 is statistically significant at the .001
level.

45


TABLE A-12 (Cont'd.)

1975-1976
ICDA PMR SE(PMR) TOTAL
Diseases of musculoskeletal
system & connective tissue 710-738 128 29 68
Rheumatoid arthritis 712 = 5
Osteoarthritis 713 -—— 23
Other & unspecified arthritis 710-711,
714-715 cS 7
Displacement of intervertebral
disc 725 => 5
Accidents, poisonings, & violence 800-999 — 33

--- The expected total number of disabled workers is less than 25 and the PMR is not
significant at the .001 level. .
* The difference between PMR and 100 is statistically significant at the .05 level.
** The difference between PMR and 100 is statistically significant at the .01 level.
*kk The difference between PMR and 100 is statistically significant at the .001 level.

87

1 US. QOVERNWENT PAINTING OFFICE 1985 - 559-112/10852


TABLE A-2 (Cont'd.)

1969-1973 1975-1976
ICDA PMR SE(PMR) TOTAL PMR SE(PMR) TOTAL

Congenital anomalies 740-759 992 28 45 111 17
Symptoms & ill-defined

conditions — 10
Accidents, poisonings, &

violence 800-999 208 *** 16 867 140 29 137
Unknown or not classifiable ad 1

--- The expected total number of disabled workers is less than 25 and the PMR is not
significant at the .001 level.
* The difference between PMR and 100 is statistically significant at the .05 level.
*k The difference between PMR and 100 is statistically significant at the .01 level.
*kk The difference between PMR and 100 is statistically significant at the .001 level.

66


Rogan, J.M., M.D. Attfield, M Jacobsen, S. Rae, D.D. Walker, and W.H. Walton.
1973. Role of Dust in the Working Environment in Development of Chronic
Bronchitis in British Coal Miners. Brit J Industry Med 30:217-226.

Rosmanith, J. 1971. The Development of Polyarthritis in Coal Miners with
Round-opacity Pneumoconiosis. Arbeitsmedizin Sozialmedizin Arbeitshygiene
6(11) 296-298.

Rudo, M. 1970. Psychic Demands of Mining Coal In: Papers and Proceedings of
the National Conference on Medicine and the Federal Coal Mine Health and
Safety Act of 1969. pp 82-83. Washington, D.C.

St. Clair Renard, K.G. 1974. Respiratory Cancer Mortality in an Iron Ore
Mine in Northern Sweden. Ambio 2:67-69.

Sataloff, J., L. Vassallo, and H. Menduke. 1969. Hearing Loss from Exposure
to Interrupted Noise. Arch Environ Health 18:972-981.

Schwartz, R. 1970. Non-respiratory Illnesses of Coal Miners. In: Papers
and Proceedings of the National Conference on Medicine and the Federal Coal
Mine, Health and Safety Act of 1969. pp. 269-274. Washington, D.C.

Social Security Administration 1971. Social Security Programs in the United
States U.S. DHEW, SSA. DHEW Pub. No. (SSA) 72-11902.

Social Security Administration, 1982. Annual Statistical Supplement, Social

Security Bulletin. U.S. DHHS, SSA. See the "Glossary" pages 263 to 274 for
basic definitions.

Solomon, A. 1977. Massive Fibrosis in Gold Miners - a Radiological
Evaluation. Env. Res. 13(1):47-55.

Steinberg, E.I. 1979. Labor Mobility in 1960-65 and 1970-75. Survey of
Current Business, Vol. 59, No.1

U.S. Bureau of the Census, 1980. Statistical Abstract of the United States:
1980 (10lst edition). Washington, D.C.

U.S. Department of Health, Education, and Welfare. 1968. Eighth Revision,
International Classification of Diseases, Adapted for Use in the United
States. National Center for Health Statistics, Public Health Publication
#1963, Washington, D.C.

- 1972. Current Estimates from the Health Interview Survey. United
States - 1970. Vital and Health Statistics Publication Series, Series 10,
Number 72. Washington, D.C.

U.S. Department of Health and Human Services. 1980. Occupational
Characteristics of Disabled Workers: Analysis of Social Security Disability
Benefit Awards to Workers During 1969-1972. DHHS (NIOSH) Publication No.
80-145.

27


TABLE 4 (Cont'd.)

1969-1973 1975-1976
ICDA PMR SE(PMR) TOTAL PMR SE(PMR) TOTAL

Accidents, poisonings, &
violence 800-999 156 ** 16 268 33 *ek 15 13

--- The expected total number of disabled workers is less than 25 and the PMR is not
significant at the .001 level.
* The difference between PMR and 100 is statistically significant at the .05 level.
** The difference between PMR and 100 is statistically significant at the .01 level.
*** The difference between PMR and 100 is statistically significant at the .001 level.

39


TABLE 6 (Cont'd.)

Diseases of circulatory system
Heart & hypertensive disease
Hypertensive disease
Ischemic heart disease
Cerebrovascular disease
Cerebral thrombosis & embolism
Arteriosclerosis

Diseases of respiratory system
Bronchitis & asthma
Emphysema
Pneumoconiosis & related

diseases

Pneumoconiosis due to
silica & silicates

Bronchiectasis

Diseases of digestive system
Peptic ulcer
Chronic enteritis &
ulcerative colitis
Cirrhosis of liver

Diseases of genitourinary system
Nephritis & nephrosis
Chronic nephritis
Other diseases of urinary system

Diseases of skin & sub-
cutaneous tissue

Diseases of musculoskeletal
system & connective tissue
Rheumatoid arthritis
Osteoarthritis
Other & unspecified arthritis

Displacement of intervertebral
disc

Congenital anomalies
Accidents, poisonings, & violence

Unknown or not classifiable

ICDA

390-458
393-429
400-404
410-414
430-438
433-434
440

460-519

490-491, 493

492
515-516

515
518

520-577
531-533

563
571

580-629
580-584

582
590-599

680-709

710-738
712

713
710-711,
714-715
725
740-759

800-999

44

PMR

71
74
116
74
60
77
118

435
260
297
3641

3746

116
40
121

94
157
59

110

eK
RK

RK

wR

RAK

RK

Kak

kk

1975-1976
SE(PMR)

278
278

13

19
37

17
14

44
18
21

12

TOTAL

1393
1160
90
1018
129
28
71

2009
137
512
718

718

20

1136
35
397
39
369
33

342


TABLE 5: Estimated number and age-adjusted proportional morbidity ratios, PMR,
and standard errors, S.E.(PMR), for white males employed in
occupations in the extraction of minerals, n.e.c. (DOT 939) by
disabling condition: Social Security Disability Awards, 1969-1973,
1975-1976.

1969-1973 1975-1976
ICDA PMR SE(PMR) TOTAL PMR SE(PMR) TOTAL

All disabling conditions 15829 4574

Infective and parasitic

diseases 000-136 70 * 10 192 56 23 25
Tuberculosis 010-019 93 16 4175 — 18
Silicotuberculosis 010 1109 * 349 31 — 2
Pulmonary tuberculosis 011 73% 12) #117 -- 16
Neoplasms 140-239 42 *** 3 665 45 *kk 7 195
Malignant neoplasms 140-199 43 *** 3 «572 41 *** 7 151
Buccal cavity & pharynx 140-149 39 ** 16 32 —_— 10
Digestive organs &

peritoneum 150-159 34 *** 11 «104 34 RR 8 28
Respiratory system 160-163 51 *** 8 260 43 #kR 13 60
Bone, connective tissue,

& skin 170-173, 31 ** =18 18 10 *** 10 2
Genital organs 180-187 62 26 56 37 * 26 10
Urinary organs 188-189 23 *** 8 20 —_ 14
Other & unspecified

sites 190-199 43 ** 614 82 49% 22 27

Neoplasms of lymphatic &
hematopoietic tissue 200-209 «29 *** = 9g 56 80 30 42

Sarcoma (lympho-,
reticulo-), other

lymphomas 200,202 42 * 21 25 — 15
Leukemia 204-207. 23 *** 11 all — 20
Benign neoplasms 210-228 433 ** 18 9
Neoplasms of unspecified
nature 230-239 141 85 28 —_ 2
Endocrine, nutritional, &
metabolic diseases 240-279 «57 ** 12 283 39 #ee 12 56
Diabetes mellitus 250 51 ** 13 189 25 *k* 12 27
Diseases of blood & blood-
forming organs 280-289 154 43 40
Mental disorders 290-315 70 *** 3 918 68 ** 8 274
Schizophrenia 295 47 #RR 5 204 54 * 17 75
Neuroses 300 126 12. 321 109 18 93
Alcoholism 303 34 *eR 12 32 22 ** 18 6

40


TABLE A-4: Estimated number and age-adjusted Proportionate morbidity ratios,
PMR, and standard errors, S.E. (PMR), for white males employed in
occupations in the extraction of minerals, n.e.c. (DOT 939) by

disabling condition other than respiratory:

Disability Awards, 1969-1973, and Allowances, 1975-1976.

All disabling conditions

Infective & parasitic
disease
Tuberculosis
Silicotuberculosis
Pulmonary tuberculosis

Neoplasms
Malignant neoplasms
Buccal cavity & pharynx
Digestive organs &
peritoneum
Respiratory system
Bone, connective
tissue, & skin
Genital organs
Urinary organs
Other & unspecified
sites
Neoplasms of lymphatic &
hematopoietic tissue
Sarcoma (lympho-,
reticulo-), other
lymphomas
Leukemia
Benign neoplasms
Neoplasms of unspecified
nature

Endocrine, nutritional, &
metabolic diseases
Diabetes mellitus

Diseases of blood & blood-
forming organs

Mental disorders
Schizophrenia
Neuroses
Alcoholism

ICDA

000-136
010-019
010
011

140-239
140-199
140-149

150-159
160-163

170-173
180-187
188-189
190-199
200-209
200,202
204-207
210-228
230-239
240-279
250

280-289
290-315
295

300
303

PMR

96
127
1632
99

62
63
57

50
75

43
93
35
61

41

83
73

218
92
56

174
48

69

1969-1973
SE(PMR) TOTAL
10021
7 192
14175
* 576 31
10 «117
#66 665
ekR 8572
23 32
** 15 (104
16 = -.260
32 18
27 56
ek 16 20
* 13 82
ee 15 56
31 25
ee 20 u
9
98 28
10 283
12 189
96 40
4 918
wR 9204
* 2300321
* 20 32

1975-1976

Social Security

PMR SE(PMR) TOTAL

64
59

48
63
14

55
35

88
66
148

*
*

ak

aK

ake

14
13
21
16

33

40

14
15

10
12
26

3021

27

42

15
20

56
27

274
75
93


TABLE A-8 (Cont'd.)

1975-1976
ICDA PMR SE(PMR) TOTAL
Diseases of digestive system 520-577 142 40 68
Peptic ulcer 531-533 — 30
Cirrhosis of liver 571 = 23
Diseases of genitourinary system 580-629 —> 21
Nephritis & nephrosis 580-584 —) 16
Chronic nephritis 582 — 16
Other diseases of urinary system 590-599 = 5
Diseases of skin & sub-
cutaneous tissue 680-709 — 5)
Diseases of musculoskeletal
system & connective tissue 710-738 143 * 16 396
Rheumatoid arthritis 712 8 *RK 7 2
Osteoarthritis 713 141 35 129
Other & unspecified arthritis 710-711,
714-715 —S 12
Displacement of intervertebral
disc 725 175 41 117
Congenital anomalies 740-759 — 13
Accidents, poisonings, & violence 800-999 110 26 98

~-- The expected total number of disabled workers is less than 25 and the PMR is not
significant at the .001 level.
* The difference between PMR and 100 is statistically significant at the .05 level.
** The difference between PMR and 100 is statistically significant at the .01 level.
**k The difference between PMR and 100 is statistically significant at the .001 level.

79


TABLE 3: Estimated number and age-adjusted proportional morbidity ratios,
PMR, and standard errors, S.E. (PMR), for white males employed in
boring, drilling, cutting, and related occupations (DOT 930) by
disabling condition: Social Security Disability Awards, 1969-73,
and Allowances, 1975-1976.

1969-1973 1975-1976
ICDA PMR SE(PMR) TOTAL PMR SE(PMR) TOTAL
All disabling conditions 5434 1823
Infective & parasitic
disease 000-136 106 23. 109 —_ 10
Tuberculosis 010-019 129 29 91 --- 10
Silicotuberculosis 010 = 8
Pulmonary tuberculosis 011 134 32 82 - 10
Neoplasms 140-239 60 *** 8 312 61 * 16 101
Malignant neoplasms 140-199 61 9 263 56 * 19 78
Buccal cavity & pharynx 140-149 65 58 17
Digestive organs &
peritoneum 150-159 63 20 61 6 RE 6 2
Respiratory system 160-163 61 * 13 97 78 33 40
Bone, connective
tissue, & skin 170-173 --- 10 — 10
Genital organs 180-187 38 37 11 — 26
Urinary organs 188-189 84 59 22
Other & unspecified
sites 190-199 67 20 45
Neoplasms of lymphatic &
hematopoietic tissue 200-209 68 28 49 <> 19
Sarcoma (lympho-,
reticulo-), other
lymphomas 200,202 --- 10
Leukemia 204-207 --- 21 — 5
Benign neoplasms 210-228 — 2
Neoplasms of unspecified
nature 230-239 --- 2
Endocrine, nutritional, &
metabolic diseases 240-279 50 ** 14 83 20 *** 12 11
Diabetes mellitus 250 49 * 20 61 21 #ek 14 9
Diseases of blood & blood-
forming organs 280-289 --- 9
Mental disorders 290-315 49 *** 6 281 67 19 127
Schizophrenia 295 33 **k 610 78 69 37 51
Neuroses 300 80 15 75 119 39 42
Alcoholism 303 28 ** 17 9

34


DISCLAIMER

The data used in this report originated in the Disabled Worker's File,
Division of Disability Studies, Office of Disability, Social Security
Administration. This data was collected by the Social Security
Administration. Mention of a company name or a product does not constitute
endorsement by the National Institute for Occupational Safety and Health or
the Social Security Administration.

NIOSH Project Officer: Thomas J. Fischach
SSA Project Officer: Jerome H. Green

DHHS (NIOSH) Publication No. 85-105

di


TABLE 12: Estimated number and age-adjusted proportional morbidity ratios,
PMR, and standard errors, S.E.(PMR), for white males employed in
boring, drilling, cutting, and related occupations (DOT 930) in

oil and gas extraction industries (SIC 130-138) by disabling
condition: Social Security Disability Allowances, 1975-1976.

All disabling conditions

Neoplasms
Malignant neoplasms
Respiratory system
Neoplasms of lymphatic &
hematopoietic tissue

Endocrine, nutritional, &
metabolic diseases
Diabetes mellitus

Mental disorders
Neuroses

Diseases of nervous system &
sense organs
Multiple sclerosis

Diseases of circulatory system
Heart & hypertensive disease
Ischemic heart disease
Cerebrovascular disease
Arteriosclerosis

Diseases of respiratory system
Emphysema

Diseases of digestive system
Chronic enteritis &
ulcerative colitis
Cirrhosis of liver

Diseases of musculoskeletal
system & connective tissue
Osteoarthritis

Displacement of intervertebral

disc

Congenital anomalies

ICDA

140-239
140-199
160-163

200-209
240-279
250
290-315
300
320-389
340
390-458
393-429
410-414
430-438
440

460-519
492

520-577
563
571
710-738
713
725
740-759

57

PMR

aKK
ak

1975-1976
SE (PMR)

33
30

12
16

19

44

25

25
29

31

40

TOTAL
447
24

20
20

42
10

139
111
111

10

143
43

83

10


Table 6: Estimated number and age~adjusted proportional morbidity ratios,
PMR, and standard errors, S.E. (PMR), for white males employed in
the extraction of minerals (DOT 930-939) in mining industries (SIC
100-149) by disabling condition:

Allowances, 1975-1976.

All disabling conditions

Infective & parasitic diseases
Tuberculosis
Pulmonary tuberculosis

Neoplasms
Malignant neoplasms
Digestive organs & peritoneum
Respiratory system
Bone, connective tissue, &
skin
Genital organs
Urinary organs
Other & unspecified sites
Neoplasms of lymphatic &
hematopoietic tissue
Sarcoma (lympho-,reticulo-),
other lymphomas
Leukemia
Neoplasms of unspecified nature

Endocrine, nutritional,
& metabolic diseases
Diabetes mellitus

Diseases of blood & blood-
forming organs

Mental disorders
Schizophrenia
Neuroses
Alcoholism

Diseases of nervous system
& sense organs
Multiple sclerosis
Cataract
Glaucoma
Blindness

000-136
010-019
O11

140-239
140-199
150-159
160-163

170-173
180-187
188-189
190-199

200-209

200,202
204-207
230-239

240-279
250

280-289

290-315
295
300
303

320-389
340
374
375
379

43

PMR

67
41
138
17

keK
RK
aK
RAK

RKE

aKE

aK
aK

REE
aK

KK

RK

Social Security Disability

1975-1976
SE(PMR)

20
29

10
19
15

TOTAL
6075

26
19
19

274
216
40
81

2
39
14
40

54

15
20
4

64
35

10

362
76
156
6

221
14
10

29


Disabling Conditions Causing Elevated PMR's, by Occupation and Industry

Classified All mining Coal mining Oil and gas Metal and
by
occupation industries (SIC 110-121) extraction nonmetal mining
(SIC_ 100-149) (SIC_130-138) (SIC_100-109)
All mining Respiratory Respiratory Musculo- Respiratory
occupations skeletal &
(930-939) connective
tissue
Boring, Respiratory Musculo-
drilling, and skeletal &
cutting connective
(DOT 930) tissue

Extraction of Respiratory Respiratory
minerals, nec
(DOT _939)

Reanalysis Without Respiratory System Disease Caused Cases

PMR's were recalculated excluding all disabilities caused by diseases of the
respiratory system since the very high association between these diseases and
mining could obscure associations between mining and other occupation-related
diseases. This follows from the negative functional dependence between PMR's
for several diseases for any given industry; diseases compete for proportions
of the total incidence, here, of disabilities. This procedure tends to offset
one limitation of PMR analyses.

Results of these analyses are presented in Tables A-1 to A-12 in the

Appendix. For all mining occupations (Table Al) the PMR's for all diseases of
the musculoskeletal system, for osteoarthritis, and for displacement of
intervertebral disc were significantly high for both periods. The patterns
for individual occupations (see Tables A-2 to A-5) were much the same except
that the individual PMR's for diseases of the musculoskeletal system,
osteoarthritis, and displacement of intervertebral disc , while high, were not
always significant for both periods. The pattern for all mining occupations
held for mining occupations restricted to the mining industry for 1975-76 (see
Table A-5). For the bituminous, lignite, and anthracite coal mining industry
(Table A-8), the PMR's for diseases of the musculoskeletal system,
osteoarthritis, and displacement of intervertebral disc for 1975-76 were all
greater than 100.0 but only that for diseases of the musculoskeletal system
was significant. For the oil and gas extraction industries (Table A-10) the
PMR for displacement of intervertebral disc was very large, and statistically
significant. The PMR for diseases of the musculoskeletal system was also
significantly high while that for osteoarthritis was high but not

significant.

17


RESULTS

Mining Occupations: All Industries

A general pattern of morbidity was observed for white males employed in mining
occupations (DOT 930-939) in all industries for both 1969-1973 and 1975-1976
(Table 2). Disability from diseases of the respiratory system was more than
three times that expected. The PMR's for emphysema and all pneumoconioses for
1969-73 and 1975-76 were significant. The PMR for pneumoconiosis from silica
and silicates was also significant for both 1969-1973 and 1975-76. All awards
or allowances given for the pneumoconioses were due to pneumoconiosis from
silica and silicates which includes silicosis, coal worker's pneumoconiosis,
and other pneumoconioses. The number of disabled workers for pneumoconiosis
from silica and silicates was 23 times the expected number in 1969-73 and more
than 32 times that expected in 1975-76. The difference between the two
periods was statistically significant (significance at the 0.001 level was
required). Thus, the excess of observed disabilities over the expected number
of disabilities for pneumoconiosis from silica and silicates was greater for
1975-76 than for 1969-73,

The PMR for bronchitis and asthma was significantly high for 1969-1973 but not
for 1975-76 . A PMR for bronchiectasis was not calculated due to the small
number of disabilities from this cause. The observed PMR's for tuberculosis
were less than 100.0 for both periods. However, the number of men disabled
from silicotuberculosis was more than nine times the expected number in
1969-1973 and the PMR was statistically significant. But, the number of
disabilities caused by silicotuberculosis was smaller than the minimum
required to estimate a PMR for 1975-76. The estimated number of white male
miners disabled from that cause decreased from an average of nearly eight per
year for the 1969-73 period to one per year for the 1975-76 period. This
difference was not statistically significant.

Contrary to expectations, a statistically significant relative deficit of
disabilities due to respiratory system cancer was observed for khoth 1969-73
and 1975-76. Also, significantly fewer than expected disabilities from cancer
of the digestive organs and peritoneum occurred for both 1969-73 and 1975-76,

The PMR's for circulatory disease for both periods were not statistically
significant.

Fewer disabilities than expected occurred for diseases of the digestive
system. For the period 1969-73, this difference was statistically
significant. Although the observed PMR for peptic ulcer was high for the
1975-76 dataset, it was not significant.

The proportion of disabilities due to diseases of the musculoskeletal system

and connective tissue was greater than expected, but achieved statistical
significance only in the 1975-76 data. A statistically significant deficit of

-13-


Gamble, J., and R. Spirtas. 1976. Job Classification and Utilization of the
Complete Work Histories in Occupational Epidemiology. Journal of Occupational
Medicine, Vol. 18, No. 6, p. 399-404,

Guralnick, L. 1963. Mortality by Occupation and Cause of Death Among Men 20
to 64 Years of Age, United States, 1950. Vital Statistics-Special Reports 53:
Numbers 2-4, Public Health Service, National Vital Statistics Division,
Washington, D.C.

Higgins, I.T.T. and A.L. Cochrane. 1961. Chronic Respiratory Disease in a
Random Sample of Men and Women in the Rhondda Fach in 1958. Brit J Industry
Med 18:93-102.

Higgins, I.T.T., M.W. Higgins, M.D. Lockshin, and N. Canale. 1968. Chronic
Respiratory Disease in Mining Communities in Marion County, West Virginia.
Brit J Industry Med 25(3):165-175.

Higgins, I1.T.T., M.S. Oh, and D.E. Whittaker. 1981. Chronic Respiratory
Disease in Coal Miners. Public Health Service, U.S. Dept of Health and Human
Services. Morgantown, West Virgina.

Hueper, W.C. 1942. Occupational Tumors and Allied Diseases. Charles C.
Thomas, Baltimore.

Hurley, J.F., J. Burns, L. Copland, J. Dodgson, M. Jacobsen. 1982,
Coalworkers' Simple Pneumoconiosis and Exposure to Dust at 10 British
Coalmines. Brit J Industry Med 39(2):120-127.

Ianssen, C. 1971. Silicosis Screening and Prevention in a Norwegian Mining
Region. Tidsskrift for Dennorske Laegeforening 91( 35-36) :2545-2548,

Ianssen, H.S. 1973. A Study of Mortality from Lung Cancer among Miners in
Kiruna 1950-1970. Work Environment Health 10:126-133.

Kaminski, R. and R. Spirtas. 1980. Industrial Chracteristics of Persons
Reporting Morbidity during the Health Interview Surveys Conducted in
1969-1974: An Exploratory Review. Public Health Service, Dept of Health and
Human Services, Washington, D.C.

Key, M.M. and H.E. Ayer. 1972. Silicosis in Hard Rock Mining. JOM
14(11) :863-865.

Lansing, J.B. and E. Mueller. 1976. The Geographic Mobitity of Labor. Survey
Research Center, Institute for Journal Research, The University of Michigan,
Ann Arbor, Michigan.

Lapp, N.L. 1969. History and Epidemiology of Coalworkers' Pneumoconiosis.
The Virginia Med Monthly 96:709-711.

Liddell, F.D.K. 1973. Morbidity of British Coal Miners in 1961-1962. Brit J
Industry Med 30(1):1-14.

25


TABLE 8 (Cont'd.)

ICDA
Cerebrovascular disease 430-438
Cerebral thrombosis & embolism 433-434
Arteriosclerosis 440
Diseases of respiratory system 460-519
Bronchitis & asthma 490-491, 493
Emphysema 492
Pneumoconiosis & related
diseases 515-516
Pneumoconiosis due to
silica & silicates 515
Bronchiectasis 518
Diseases of digestive system 520-577
Peptic ulcer 531-533
Chronic enteritis &
ulcerative colitis 563
Cirrhosis of liver 571
Diseases of genitourinary system 580-629
Nephritis & nephrosis 580-584
Chronic nephritis 582
Other diseases of urinary system 590-599
Diseases of skin & sub-
cutaneous tissue 680-709
Diseases of musculoskeletal
system & connective tissue 710-738
Rheumatoid arthritis 712
Osteoarthritis 713
Other & unspecified arthritis 710-711,
714-715
Displacement of intervertebral
disc 725
Congenital anomalies 740-759
Accidents, poisonings, & violence 800-999

Unknown or not classifiable

49

PMR

65
103
86
460
251
322
3830

3938

76

112
119
97
141
45
129

*

kK

RK

ek

AK

kk

ak

1975-1976
SE(PMR)

15
45
24
24
77
39
370

383

18

15
49

10
23
48
22
17
17

TOTAL

10

758
274
28
228
17
269


TABLE A-3: Estimated number and age-adjusted proportional morbidity ratios,
PMR, and standard errors, S.E. (PMR), for white males employed in
loading and conveying occupations (DOT 932) by disabling condition
other than respiratory: Social Security Disability Awards,
1969-1973, and Allowances, 1975-1976,

1969-1973 1975-1976
ICDA PMR SE(PMR) TOTAL PMR SE(PMR) TOTAL
All disabling conditions 1583 571
Infective and parasitic
diseases 000-136 = 45 35 15
Tuberculosis 010-019 —~- 15
Silicotuberculosis 010 1
Pulmonary tuberculosis O11 - oe 15
Neoplasms 140-239 60 * als) 99 43 25 25
Malignant neoplasms 140-199 45 ** 615 61 50 29 25
Buccal cavity & pharynx 140-199 45 ** 15 61 50 29 25
Digestive organs &
peritoneum 150-159 16 *** «617 5 _ 10
Respiratory system 160-163 69 32 35
Bone, connective tissue,
& skin 170-173 ~-- 5
Urinary organs 188-189 --- 4
Other & unspecified
sites 190-199 ~-- 6 — 15
Neoplasms of lymphatic &
hematopoietic tissue 200-209 166 64 38

Sarcoma (lympho~,
reticulo-), other

lymphomas 200,202 -— 6
Leukemia 204-207. —- 10
Benign neoplasms 210-288
Endocrine, nutritional, &
metabolic diseases 240-279 69 25 36 — 25
Diabetes mellitus 250 81 33 32 — 20
Diseases of blood & blood-
forming organs 280-289 > 10
Mental disorders 290-315 91 15 165 71 24 40
Schizophrenia 295 81 27 60 <> 5
Neuroses 300 88 34 27 — 25
Alcoholism 303 — 15

Diseases of nervous system &
sense organs 320-389 40 * 19 42 85 32 30

67


DISCUSSION

The pattern of disability that emerges for persons employed in mining
occupations was weighted heavily toward diseases of the respiratory system.
Elevations of the PMR's for silicotuberculosis, emphysema, pneumoconiosis,
silicosis, and asthma and bronchitis were significant. Considering that the
extremely high PMR's for respiratory diseases must be balanced by reduced
PMR's for other diseases, it was not surprising that the PMR's for most of the
other diseases were lower than expected. The PMR for cancer of the
respiratory system was much lower than expected, as was the PMR for all
neoplasms. Diseases of the digestive system, including peptic ulcer and
cancer, produced fewer disabilities than expected. Significantly fewer
disabilities were observed for endocrine, nutritional, and metabolic diseases,
including diabetes mellitus. The proportion of disabilities from
musculoskeletal and connective tissue diseases were modestly higher than
expected. Rheumatoid arthritis contributed significantly less disability than
expected while osteoarthritis and slipped disc contributed more. Accidents
were also important causes of disability.

Pneumoconiosis has been identified for many years as the major occupational
disease associated with underground coal mining. More recently,
pneumoconiosis has been reported in employees of surface coal mines and of
other mining industries. The leading cause of excess Social Security
disability awards or allowances among mining employees for both periods
analyzed in this study was pneumoconiosis due to silica and silicates. For
all mining industries combined, coal mining, and metal and nonmetallic mineral
mining, there was a significant excess of disabilities awarded for
pneumoconiosis due to silica and silicates.

The PMR for pneumoconiosis due to silica and silicates was higher in the
1975-76 period than in the 1969-73 period. Such a difference could signify
that an old problem has become worse. However, this difference might result
from a greater decrease in the incidence of causes of disability other than
pneumoconiosis due to silica and silicates for miners, or a greater decrease
in the incidence of pneumoconiosis due to silica and silicates for workers in
non-mining occupations than for miners. It might also reflect changes in
patterns of diagnosis, in tendencies for disabled workers to apply for
disability awards, or in administrative treatment of applications for
benefits, among many possibilities. The difference may result from the fact
that the 1969-73 data were award data while those for 1975-76 were allowance
data, although the differences between awards and allowances do not appear
large enough to account for the difference in PMR's. More research is needed
to determine the cause for the finding in this study. The direction of the
difference occurred for all mining occupations studied. In general, the
average number of workers disabled each year from pneumoconiosis due to silica
and silicates was lower for 1975-76 than for 1969-73. However, for boring,
drilling, cutting, and related occupations and for loaders and conveyors the
average number was greater for the more recent period. Such changes in
average numbers of disabled workers may be deceptive because changes in the
sizes and compositions of the populations at risk have not been considered.

19


TABLE A-11 (Cont'd.)

1975-1976
ICDA PMR SE (PMR) TOTAL
Accidents, poisonings, & violence 800-999 135 112 40
Unknown or not classifiable _ 1

~-- The expected total number of disabled workers is less than 25 and the PMR is not
significant at the .001 level.
* The difference between PMR and 100 is statistically significant at the .05 level.
** The difference between PMR and 100 is statistically significant at the .01 level.
*k*k The difference between PMR and 100 is statistically significant at the .001 level.

85




TABLE A-3 (Cont'd.)

1969-1973 1975-1976
IcDA PMR SE(PMR) TOTAL PMR SE(PMR) TOTAL
Glaucoma 375 => 1 aad 5
Blindness 379 —> 3 — 5
Diseases of circulatory
system 390-458 85 7 477 117 20 232
Heart & hypertensive
disease 393-429 97 10 419 114 21 182
Hypertensive disease 400-404 324 183 48 — 10
Ischemic heart disease 410-414 84 12 322 119 24 167
Cerebrovascular disease 430-438 51 * 16 39 — 20
Cerebral thrombosis &
embolism 433-434 --- 8
Arteriosclerosis 440 — 4 — 15
Diseases of digestive system 520-577 85 31 44 —_ 15
Peptic ulcer 531-533 --- 16 — 5
Cirrhosis of liver 571 —_ 5
Diseases of genitourinary
system 580-629 --- 14 — 5
Nephritis & nephrosis 580-584 9 5
Chronic nephritis 582 _— 9 a> 5
Diseases of male genital
organs 600-607 --— 5
Diseases of skin & sub-
cutaneous tissue 680-709 --- 10 — 5

Diseases of musculoskeletal
system & connective tissue 710-738 153 ** 16 384 170 * 30 171

Rheumatoid arthritis 712 171 53 55
Osteoarthritis 713 137 34 99 215 66 70
Other & unspecified 710-711,
arthritis 714-715 326 171 32 _ 2
Displacement of inter-
vertebral disc 725 167 37 122 — 38
Congenital anomalies 740-759 165 66 29

Accidents, poisonings, &
violence 800-999 187 * 30 268 41 ** 15 13

~~~ The expected total number of disabled workers is less than 25 and the PMR is not
significant at the .001 level.
* The difference between PMR and 100 is statistically significant at the .05 level.
** The difference between PMR and 100 is statistically significant at the .01 level.
*** The difference between PMR and 100 is statistically significant at the .001 level.

68


TABLE A-6: Estimated number and age-adjusted proportional morbidity ratios,
PMR, and standard errors, S.E. (PMR), for white males employed in
boring, drilling, cutting, and related occupations (DOT 930) in
mining industries (SIC 100-149) by disabling condition other
than respiratory: Social Security Disability Allowances,
1975-1976.

1975-1976
ICDA PMR SE(PMR) TOTAL
All disabling conditions 889
Neoplasms 140-239 71 18 63
Malignant neoplasms 140-199 64 20 47
Digestive organs & peritoneum 150-159 — 2
Respiratory system 160-163 74 39 20
Genital organs 180-187 o> 25
Neoplasms of lymphatic &
hematopoietic tissue 200-209 = 14
Neoplasms of unspecified nature 230-239 — 2
Endocrine, nutritional, & metabolic
diseases 240-279 27 Re 14 8
Diabetes mellitus 250 _ 8
Mental disorders 290-315 94 24 92
Schizophrenia 295 53 22 20
Neuroses 300 — 38
Diseases of nervous system & sense
organs 320-389 91 36 52
Multiple sclerosis 340 5 10
Blindness 379 —— 10
Diseases of circulatory system 390-458 101 11 297
Heart & hypertensive disease 393-429 107 15 252
Hypertensive disease 400-404 — 36
Ischemic heart disease 410-414 103 15 211
Cerebrovascular disease 430-438 34% 23 11
Cerebral thrombosis & embolism 433-434 — 2
Arteriosclerosis 440 — 20
Diseases of digestive system 520-577 141 75 37
Peptic ulcer 531-533 — 15
Chronic enteritis &
ulcerative colitis 563 — 2
Cirrhosis of liver 571 — 19
Diseases of genitourinary system 580-629 — 10
Nephritis & nephrosis 580-584 - 10
Chronic nephritis 582 — 10

74


A-3

A-7

Estimated number and age-adjusted proportional morbidity
ratios, PMR, and standard errors, S.E.(PMR), for white

males employed in loading and conveying occupations (DOT

932) by disabling condition other than respiratory: Social
Security Disability Awards and Allowances,

1969-1973, 1975-1976 6 6 1 ee ee ee ee es

Estimated number and age-adjusted proportionate morbidity
ratios, PMR, and standard errors, S.E.(PMR), for white

males employed in occupations in the extraction of minerals,
n.e.c. (DOT 939) by disabling condition other than
respiratory: Social Security Disablity Awards and Allowances,
1969-1973, 1975-1976 2 6 6 ww www ew tw ww

Estimated number and age-adjusted proportionate morbidity
ratios, PMR, and standard errors, S.E.(PMR), for white

males employed in the extraction of minerals (DOT 930-939)
in mining industries (SIC 100-149) by disabling condition
other than respiratory: Social Security Disability Awards
and Allowances, 1969-1973, 1975-1976 ......2560080828

Estimated number and age-adjusted proportionate morbidity
ratios, PMR, and standard errors, S.E.(PMR), for white

males employed in boring, drilling, cutting, and related
occupations (DOT 930) in mining industries (SIC 100-149)

by disabling condition other than respiratory: Social
Security Disability Allowances, 1975-1976 ......-2..004

Estimated number and age~adjusted proportionate morbidity
ratios, PMR, and standard errors, S.E.(PMR), for white

males employed in occupations in the extraction of minerals,
n.e.c. (DOT 939) in mining industries (SIC 100-149) by
disabling condition other than respiratory: Social Security
Disability Allowances, 1975-1976 . 2... 1. ee es eee

Estimated number and age-adjusted proportionate morbidity
ratios, PMR, and standard errors, S.E.(PMR), for white

males employed in extraction of minerals (DOT 930-939) in
bituminous, lignite, and anthracite coal mining (SIC 110-121)
by disabling condition other than respiratory: Social
Security Disability Allowances, 1975-1976 .....4..4...

vili

67

69

72

74

76

78


TABLE A-5: Estimated number and age-adjusted proportional morbidity ratios,
PMR, and standard errors, S.E. (PMR), for white males employed
in the extraction of minerals (DOT 930-939) in mining industries
(SIC 100-149) by disabling condition other than respiratory:
Social Security Disability Allowances, 1975-1976,

All disabling conditions
Infective & parasitic diseases

Neoplasms
Malignant neoplasms
Digestive organs & peritoneum
Respiratory system
Bone, connective tissue, &
skin
Genital organs
Urinary organs
Other & unspecified sites
Neoplasms of lymphatic &
hematopoietic tissue
Sarcoma (lympho-,reticulo-),
other lymphomas
Leukemia
Neoplasms of unspecified nature

Endocrine, nutritional, & metabolic
diseases
Diabetes mellitus

Diseases of blood & blood-
forming organs

Mental disorders
Schizophrenia
Neuroses
Alcoholism

Diseases of nervous system & sense
organs
Multiple sclerosis
Cataract
Glaucoma
Blindness

Diseases of circulatory system
Heart & hypertensive disease

ICDA

000-136

140-239
140-199
150-159
160-163

170-173
180-187
188-189
190-199

200-209

200, 202
204-207
230-239

240-279
250

280-289

290-315
295
300
303

320-389
340
374
375
379

390-458
393-429

72

PMR

87
50
186
23

aK
Rk

RkK

ak
aeRK

akK
kk
ae

1975-1976
SE(PMR)

29

10
20
17

10
60

29
42

13
12

26
18

il

15
20

64

10

362
76
156

221
14
10

29

1393
1160


TABLE A-10 (Cont'd.)

1975-1976
ICDA PMR SE(PMR) TOTAL
Congenital anomalies 740-759 — 10
Accidents, poisonings, & violence 800-999 117 82 46
Unknown or not classifiable a 1

—-- The expected total number of disabled workers is less than 25 and the PMR is not
significant at the .001 level.
* The difference between PMR and 100 is statistically significant at the .05 level.
** The difference between PMR and 100 is statistically significant at the .01 level.
**k The difference between PMR and 100 is statistically significant at the .001 level.

83


TABLE 9: Estimated number and age-adjusted proportional morbidity ratios,
PMR, and standard errors, S.E. (PMR), for white males employed in
extraction of minerals (DOT 930-939) in bituminous, lignite, and

anthracite coal mining (SIC 110-121) by disabling condition:
Social Security Disability Allowances, 1975-1976

All disabling conditions

Infective & parasitic diseases
Tuberculosis
Pulmonary tuberculosis

Neoplasms

Malignant neoplasms
Digestive organs & peritoneum
Respiratory system
Genital organs
Urinary organs
Other & unspecified sites

Neoplasms of lymphatic &
hematopoietic tissue

Endocrine, nutritional, &
metabolic diseases
Diabetes mellitus

Diseases of blood & blood-
forming organs

Mental disorders
Schizophrenia
Neuroses
Alcoholism

Diseases of nervous system & sense
organs
Cataract
Blindness

Diseases of circulatory system
Heart & hypertensive disease
Hypertensive disease
Ischemic heart disease
Cerebrovascular disease
Cerebral thrombosis & embolism
Arteriosclerosis

ICDA

000-136
010-019
oll

140-239
140-199
150-159
160-163
180-187
188-189
190-199

200-209

240-279
250

280-289

290-315
295
300
303

320-389
374
379

390-458
393-429
400-404
410-414
430-438
433-434
440

51

PMR

kK
aK

ak

kKK
KE

ak

aK

aK

RE

1975-1976
SE(PMR)

43

10
15
37

15

37

14
27

TOTAL
2629
20
15
100
90
17
20
21

10

187


TABLE 7 (Cont'd.)

1975-1976
ICDA PMR SE(PMR) TOTAL
Diseases of digestive system 520-577 114 40 37
Peptic ulcer 531-533 — 15
Chronic enteritis &
ulcerative colitis 563 => 2
Cirrhosis of liver 571 5 19
Diseases of genitourinary system 580-629 = 10
Nephritis & nephrosis 580-584 — 10
Chronic nephritis 582 = 10
Diseases of musculoskeletal
system & connective tissue 710-738 130 20 248
Osteoarthritis 713 142 31 88
Other & unspecified arthritis 710-711,
714-715 — 9
Displacement of intervertebral
disc 725 208 * 42 98
Congenital anomalies 740-759 — 16
Accidents, poisonings, & violence 800-999 98 19 65
Unknown or not classifiable Ss 1

~-- The expected total number of disabled workers is less than 25 and the PMR is not
significant at the .001 level.

* The difference between PMR and 100 is statistically significant at the .05 level.

** The difference between PMR and 100 is statistically significant at the .01 level.

**k The difference between PMR and 100 is statistically significant at the .001 level

47


Limitations of using “usual” occupation have been studied previously by Gamble
and Spirtas (1976); studies by Lansing and Mueller (1967) and by Steinberg
(1979) have dealt with occupational mobility. These studies indicated that
job changes are most likely to take place between occupations in which work
requirements are similar, among individuals who have limited training, and
that changes in occupation decrease after age 40. However, the average age of
workers in this study was greater than 50 years. Therefore, it is reasonable
to believe that the occupation indicated is representative of the worker's
major lifetime experience.

Statistical Analyses of the Data

Proportional morbidity ratios (PMR's) were used in this report because the
sizes of the various occupational populations at risk (i.e. the denominator)
were difficult to estimate with sufficient accuracy for computation of actual
disability rates. A PMR for a particular occupational group and a specific
disabling condition compares the proportion of all disabled workers in that
occupational group who have that disabling condition to the proportion of all
disabled workers in all occupations who have the same disabling condition. If
the PMR is greater than 100 it implies that workers in that occupation are
disabled by that particular condition relatively more often. The actual rate
at which workers in that occupational group are disabled by that condition,
however, may be more than, equal to, or less than the corresponding rate for
all workers of all occupations. Proportional morbidity ratios may not measure
the risk of disability from a disease for an occupational group.

The use of PMR's might be compared to comparisons between relative sizes of
pieces from two different sized pies. The first piece may be one-third of the
first pie whereas the second piece is only one-fourth of the second pie;
however, if the second pie has a 20-inch diameter and the first pie has a
10-inch diameter, the second piece is absolutely larger than the first piece,
even though the first is proportionately the larger. Thus, comparisons of
PMR's for different occupational groups must be done with great caution.
However, the frequency of the empirical occurrence of the conditions necessary
to produce great distortions in PMR's has not been estimated scientifically.
PMR's may provide reliable indications of hazards and other factors adversely
affecting the health and safety of workers, whether these factors are
completely occupational or not. A more detailed explanation of this measure
and its estimation has been published (DHHS, 1980).

Age — adjusted PMR's for white males were estimated for all combinations of
occupation and, for 1975-76, of industry by disabling condition. These were
used to describe associations between disease and occupation and/or industry.
The PMR for a specific occupation, industry, or industry-occupation for a
particular disabling condition was defined as the ratio of the observed number
of disabled workers to the expected number. For each of seven age groups, the
expected number was equal to the proportion of disabled workers for all
occupations with the specified disabling condition multiplied by the total
number of disabled workers for the selected occupation. This study used
disabled white male workers from all industries or all occupations,
respectively, combined as the comparison group for mining industries or mining
occupations or both.


TABLE 4 (Cont'd.)

1969-1973 1975-1976
ICDA PMR SE(PMR) TOTAL PMR SE(PMR) TOTAL

Diseases of circulatory

system 390-458 64 *k* 7) 477 88 11 232
Heart & hypertensive
disease 393-429 73 ** 7 419 86 12 182
Hypertensive disease 400-404 247 69 48 === 10
Ischemic heart disease 410-414 63 *** = 868 «322 90 14 167
Cerebrovascular disease 430-438 39 ** 18 39 71 50 20
Cerebral thrombosis &
embolism 433-434 --— 8
Arteriosclerosis 440 14 *kk 13 40 15
Diseases of respiratory
system 460-519 337 *** 24 634 368 *** 44 228
Bronchitis & asthma 490-491,493  -~- 15° -- 15
Emphysema 492 279 #RK 37° 32700 mee 70
Pneumoconiosis & related
diseases 515-516 2528 *** 226 207. —- 62
Pneumoconiosis due to
silica & silicates 515 2581 *** 226 2070 --- 62
Diseases of digestive system 520-577 65 230 44 --- 15
Peptic ulcer 531-533 --- 160 --- 5
Cirrhosis of liver 571 — 5
Diseases of genitourinary
system 580-629 --- 14 = -— 5
Nephritis & nephrosis 580-584 —-- 9 == 5
Chronic nephritis 582 — 9 0 = 5
Diseases of skin & sub-
cutaneous tissue 680-709 --- 10 -— 5
Disease of musculoskeletal
system & connective tissue 710-738 120 13 384 132 24 171
Rheumatoid arthritis 712 132 40 55
Osteoarthritis 713 104 23°99 161 47 70
Other & unspecified 710-711,
arthritis 714-715 249 88 32 --- 2
Displacement of inter-
vertebral disc 725 134 25 122 123 34 38
Congenital anomalies 740-759 134 60 29

38


TABLE 5 (Cont'd.)

1969-1973 1975-1976
ICDA PMR SE(PMR) TOTAL PMR SE(PMR) TOTAL

Diseases of skin & sub-
cutaneous tissue 680-709 84 39 41 =< 20

Disease of musculoskeletal
system & connective

tissue 710-738 94 4 2133 113 10 = 833
Rheumatoid arthritis 712 61 *** 7 186 69 23 45
Osteoarthritis 713 111 7 862 118 24 292
Other & unspecified 710-711,

arthritis 714-715 103 28 102 89 42 28
Displacement of inter-

vertebral disc 725 97 8 554 143 * 19 253

Congenital anomalies 740-759 53 * 15 71 40 ** 17 17
Symptoms & ill-defined

conditions 780-796 --- 14
Accidents, poisonings, &

violence 800-999 113 61 1145 130 17-304
Unknown or not classifiable — 2

--- The expected total number of disabled workers is less than 25 and the PMR is not
significant at the .001 level.
* The difference between PMR and 100 is statistically significant at the .05 level.
** The difference between PMR and 100 is statistically significant at the .01 level.
*k*k The difference between PMR and 100 is statistically significant at the .001
level.

42


Congenital anomalies

Symptoms & i111-defined
conditions

Accidents, poisonings, &
violence

TABLE A~4 (Cont'd.)

1969-1973
ICDA PMR SE(PMR) TOTAL
740-759 71 17 71
780-796 --- 14

800-999 148 *** 10 1145

1975-1976
PMR SE(PMR) TOTAL

53 * 20 17

169 ** 20 304

--- The expected total number of disabled workers is less than 25 and the PMR is not
significant at the .001 level.

* The difference between PMR and 100 is statistically significant at the .05 level.
** The difference between PMR and 100 is statistically significant at the .01 level.
**k The difference between PMR and 100 is statistically significant at the .001 level.

71


prevalence of respiratory symptoms than nonminers (Higgins and Cochrane,
1961). Miners, especially those with 30 years or more underground experience,
developed cough, breathlessness, and chest illness more frequently than
nonminers (Higgins et al., 1968).

While respiratory diseases are the most frequent occupational diseases among
miners, the prevalence of other occupational disease groups is also increased
among miners. Naeye (1970) and Wagoner et al (1963) reported excess
cardiovascular disease mortality among miners; Liddell (1973) listed
cardiovascular disease as a significant cause of work incapacity among
miners. Enterline (1972) reported excess mortality from digestive disorders
in American coal miners; Wagoner et al., (1963) noted a 1.6-fold excess in
digestive cancer mortality among uranium miners with 15 years or more of
underground mining experience. The occurrence of cor pulmonale, gastric
ulcer, and Caplan's syndrome (rheumatoid arthritis plus nodular pulmonary
densities) was increased among persons having pneumoconiosis (Schwartz,
1970). Rosmanith (1971) observed an age-related increase in the occurrence of
polyarthritis among coal miners with pneumoconiosis.

Nerve deafness and musculoskeletal disabilities are trauma-induced disorders
(Schwartz, 1970). Lumio (1965) studied the effects of occupational noise on
the hearing of workers in the mining, textile, paper, and metal industries.
In the mining industry, 21 percent of the workers had severe hearing losses.
Sataloff et _al., (1969) detected hearing losses in 22 percent in a group of
iron miners. NIOSH (1976) reported measurably worse hearing in underground
coal miners than the national average. Liddell (1973) and Rudo (1970)
reported an increased occurrence of musculoskeletal disorders among miners.

Summar-

The occurrence of the following diseases appears higher for employees of the
mining industry: tuberculosis, lung cancer, cancer of the stomach,
cardiovascular disease including cor pulmonale, diseases of the digestive
system including gastric ulcer, silicosis and other forms of pneumoconiosis,
other chronic respiratory diseases, arthritis and other musculoskeletal
disorders, and accidents. Hearing loss is also well documented among persons
employed in the mining industry. Such loss, while a functional impairment,
may not cause disability if the affected individual is able to continue
working.

While lung cancer has been most frequently associated with uranium, iron, and
other metal mining, it may also be related to coal mining. The risks of
pneumoconiosis and chronic respiratory diseases appear greater for coal mining
than for other types of mining, although both types of mining appear to be at
greater risk for these diseases than non-mining industries. Within the coal
mining industry, underground workers appear to be at greater risk for
pneumoconiosis and other chronic respiratory disease than surface miners. In
all these cases the risk of disease ~ whether lung cancer, pneumoconiosis, or
other chronic respiratory disease - appears to be related directly to the
length of employment. Hence, it might be expected that older workers would be
at higher risk than young workers for these diseases.

-4-


TABLE 7: Estimated number and age-adjusted proportional morbidity ratios,
PMR, and standard errors, S.E. (PMR), for white males employed in
boring, drilling, cutting, and related occupations (DOT 930) in
mining industries (SIC 100-149) by disabling condition: Social
Security Disability Allowances, 1975-1976.

All disabling conditions

Neoplasms

Malignant neoplasms
Digestive organs & peritoneum
Respiratory system
Genital organs

Neoplasms of lymphatic &
hematopoietic tissue

Neoplasms of unspecified nature

Endocrine, nutritional, & metabolic
diseases
Diabetes mellitus

Mental disorders
Schizophrenia
Neuroses

Diseases of nervous system & sense
organs
Multiple sclerosis
Blindness

Diseases of circulatory system
Heart & hypertensive disease
Hypertensive disease
Ischemic heart disease
Cerebrovascular disease
Cerebral thrombosis & embolism
Arteriosclerosis

Diseases of respiratory system
Bronchitis & asthma
Emphysema
Pneumoconiosis & related

diseases
Pneumoconiosis due to
silica & silicates

ICDA

140-239
140-199
150-159
160-163
180-187

200-209
230-239

240-279
250

290-315
295
300

320-389
340
379

390-458
393-429
400-404
410-414
430-438
433-434
440

460-519
490-491, 493
492

515-516

515

46

1975-1976

PMR, SE(PMR) TOTAL
1183

58 * 17 63
51 * 20 47
10 *e* 8 2
59 32 20
_ 25
— 14
— 2
22 week 14 8
29 ** 19 8
80 24 92
47 * 23 20
_ 38
75 22 52
_ 10
= 10
80 10 297
85 10 252
— 36
82 10 211
27 #RK 13 11
— 2
— 20
339 *eK 38 294
— 30
161 46 52
3364 #** 636 120
3461 #e* 647 120


Preface . 2. 2 se ee ee ee ewe
Abstract... 66 2 ee eee eee
Acknowledgements .. 2... 2.2.65
Introduction . 2... 6 ee ee eee
Literature Review . 2... 2.246

Materials and Methods .......

CONTENTS

Surveillance Hypotheses for This Study... .

Results . 6.6 6 1 ee et te
Discussion «6.6 1 2 ee ee eee
Bibliography .. 2... 6. 2 2 es wee

Appendix: Tables of PMRs Calculated
Diseases of the Respiratory System .

Excluding

All

TABLES

tii

iv

11
13
19
24

Disabilities Caused by

1. Diseases and ICDA~8 codes analysed in this report .......

2. Estimated number and age-adjusted proportional morbidity
ratios, PMR, and standard errors S.E.(PMR), for white males
employed in the extraction of minerals (DOT 930-939) by

Social Security Disability Awards

disabling condition:

and Allowances, 1969-1973, 1975-1976 . .

61

29

31


Congenital anomalies

Symptoms & ill-defined
conditions

Accidents, poisonings, &
violence

Unknown or not classifiable

TABLE A-1 (Cont'd.)

1969-1973
ICDA FMR SE(PMR) TOTAL
740-759 = 85 11 145
780-796 --~ 14
800-999 171 *** 8 2318

1975-1976
PMR SE(PMR) TOTAL

61 19 34

_ 10

147 ** 130 459

-— 3

--~ The expected total number of disabled workers is less than 25 and the PMR is not
significant at the .001 level.

* The difference between PMR and 100 is statistically significant at the .05 level.
** The difference between PMR and 100 is statistically significant at the .01 level.
**k The difference between PMR and 100 is statistically significant at the .001 level.

63


The other cause of disability which became statistically significant was
accidents, poisoning, and violence. For mining occupations in all industries
the PMR for accidents, poisoning, and violence was significantly high for both
periods. This was also true for the PMR for accidents, poisoning, and
violence for the mining industry restricted to mining occupations for

1975-76. For coal mining (bituminous, lignite, and anthracite coal mining)
the PMR for accidents, poisoning, and violence for 1975-76 was high but it was
not significant.

For mining occupations for all industries, the PMR for tuberculosis was
observed higher than 100.0 for 1969-73 but was not significant. However, the
PMR for silicotuberculosis, which was significantly high in the previous
analysis, was not significant although the number of cases was 13 times the
number expected for 1969-73. The PMR's for neoplasms and diseases of the
circulatory system were still significantly low for both periods but at lower
levels of significance as the occurrence of disabilities caused by these
diseases approached that expected under the null hypothesis. The PMR for
respiratory system neoplasms was low for both periods but was significant only
for 1969-73 The PMR for neoplasms of the digestive organs and peritoneum was
significantly low for both periods. The PMR's for diseases of the circulatory
system were significantly low for 1969-73 but not for 1975-76.

No PMR's for diseases not expected to be related to mining were found to be
significantly high with this analysis.

18


TABLE A~1: Estimated number and age-adjusted proportional morbidity ratios,
PMR, and standard errors, S.E.(PMR), for white males employed in
the extraction of minerals (DOT 930-939) by disabling condition
other than respiratory: Social Security Disability Awards,
1969-1973, and Allowances, 1975-76.

1969-1973 1975-1976
ICDA PMR SE(PMR) TOTAL PMR SE(PMR) TOTAL
All disabling conditions 16138 5114
Infective and parasitic
diseases 000-136 101 13 332 21 * 25 7
Tuberculosis 010-019 127 18 287
Silicotuberculosis 010 1333 733 39
Pulmonary tuberculosis 011 113 16 220
Neoplasms 140-239 64 *** 4 1104 66 ** 8 341
Malignant neoplasms 140-199 64 *** 6 909 63 ** 10 274
Buccal cavity & pharynx 140-149 63 18 55 —_ 10
Digestive organs &

peritoneum 150-159 52 *#** = «10, 170 41 ** 15 40
Respiratory system 160-163 73% 10 392 73 14 116
Bone, connective tissue,

& skin 170-173 63 30 44 — 12
Genital organs 180-187 71 18 67 124 52 40
Urinary organs 188-189 51 * 17 46 55 33 14
Other & unspecified

sites 190-199 62 * 13 135 63 25 42

Neoplasms of lymphatic &
hematopoietic tissue 200-209 69 14 158 94 36 61

Sarcoma (lympho-,
reticulo-), other

lymphomas 200,202 75 23 51 -— 15
Leukemia 204-207. 75 28 42 — 25
Benign neoplasms 210-228 27 ** 19 9 -— 2
Neoplasms of unspecified
nature 230-239 118 63 28 = 4
Endocrine, nutritional, &
metabolic diseases 240-279 74 ** 7 402 54 *k 14 92
Diabetes mellitus 250 69 ** 9 282 43* 16 56
Diseases of blood & blood-
forming organs 280-289 164 56 49 — 10
Mental disorders 290-315 81 #** 3 1391 83 10 451
Schizophrenia 295 57 eK 6 342 67 17 136
Neuroses 300 143 ** 10 432 150 23 160
Alcoholism 303 53 ** 14 56 18 **% 15 6

61


TABLE 10 (Cont'd.)

1975-1976
ICDA PMR SE(PMR) TOTAL
Pneumoconiosis & related
diseases 515-516 4929 xk 676 311
Pneumoconiosis due to
silica & silicates 515 5065 *** 708 311
Diseases of digestive system 520-577 103 35 53
Peptic ulcer 531-533 — 20
Cirrhosis of liver 571 71 33 18
Diseases of genitourinary system 580-629 11
Nephritis & nephrosis 580-584 6
Chronic nephritis 582 — 6
Other diseases of urinary system 590-599 _ 5
Diseases of musculoskeletal
system & connective tissue 710-738 91 15 271
Rheumatoid arthritis 712 8 ReK 7 2
Osteoarthritis 713 90 30 92
Other & unspecified arthritis 710-711,
714-715 — 10
Displacement of intervertebral
disc 725 117 28 81
Congenital anomalies 740-759--- 7
Accidents, poisonings, & violence 800-999 101 29 88

--- The expected total number of disabled workers is less than 25 and the PMR is not
significant at the .001 level.
* The difference between PMR and 100 is statistically significant at the .05 level.
** The difference between PMR and 100 is statistically significant at the .01 level.
*kk The difference between PMR and 100 is statistically significant at the .001 level.

54


SURVEILLANCE HYPOTHESES FOR THIS STUDY

The two surveillance objectives of this study are: (1) To monitor
relationships found in previous research between causes of disability and
employment in mining industries and occupations; and (2) To detect emergent or
previously undetected relationships. Hypotheses were formulated to accomplish
each of these objectives. To accomplish the first objective, each of the
relationships summarized in the Literature Review Section, with a few
exceptions to be noted presently, was studied. The appropriate national PMR
for white men was estimated and a statistical test of the null hypothesis that
it was less than or equal to 100.0 was performed. A one-tail Student's t-test
(with 19 degrees of freedom - see DHHS, 1980 — for the statistical
justification) at the 0.05 probability level of significance was used. These
relationships were tested for each mining industry or occupation as there was
no a priori basis to exclude any.

To accomplish the second objective, national PMR's for all other combinations
of mining industry or occupation and disabling conditions were estimated and
statistically analyzed. In each case the hypothesis that the national PMR was
less than or equal to 100.0 was tested with a Student's t-test in a manner
similiar to that described in the preceding paragraph except for the
probability level of the test. Since the alternative hypothesis had not been
suggested a priori, e.g., in the literature, the level of significance was set
at 0.001. This tended to ensure that the overall error probability, of
inferring one or more high national PMR's to be greater than 100.0 when none
were, would be approximately 0.05 for each mining industry or occupation
studied. This allows for the fact that there are 67 different disabling
condition PMR's for each mining industry or occupation which could be falsely
higher than 100.0 by sampling error.

The literature review indicates that the occurrence of cor pulmonale appears
to be higher for miners with pneumoconiosis and other chronic respiratory
diseases such as bronchitis and emphysema. However, only three digit ICDA
codes were available and fourth digit coding would be necessary to study cor
pulmonale. Thus, this study cannot examine PMR's for cor pulmonale. Nor was
it known whether workers disabled from cor pulmonale would be included with
those coded for circulatory disease or for the associated respiratory
disease.

Similarly, there was no grouping for chronic respiratory diseases. The
individual PMR's for bronchitis and asthma, emphysema, and bronchiectasis were
examined, but only if not precluded by small numbers of cases. The lack of
coding in more detail than the three digit level also meant that it was not
possible to study the various types of pneumoconiosis, e.g. silicosis, coal
workers pneumoconiosis, etc., separately. Similarly, the coding did not
separate accidents from poisonings and violence so that the category of
accidents, poisonings, and violence was used.

Sail


U.S. Department of Labor, 1965. Dictionary of Occupational Titles, Vols., 1
and 2, 3rd Edition. U.S. Government Printing Office, Washington, D.C.

Wagoner, J.K., R.W. Miller, F.E. Lundin Jr., J.F. Fraumeni Jr., and M.E.Haij.
1963. Unusual Cancer Mortality Among a Group of Underground Metal Miners.
NEJM 269 (6): p. 284-289.

Wagoner, J.K., V.E. Archer, B.E. Carroll, D.A. Holaday, and P.A. Lawrence.
1964. Cancer Mortality Patterns Among U.S. Uranium Miners and Millers, 1950
Through 1962. J. Nat. Cancer Inst. 32: p. 787-801.

Wagoner, J.K., V.E. Archer, F.E. Lundin Jr., D.A. Hiliday, and J.W. Lloyd.

1965. Radiation as a Cause of Lung Cancer Among Uranium Miners NEJM (4) 273:
p. 181-188.

Wilks, Samuel S. 1962. Mathematical Statistics. John Wiley and Sons, Inc.,
New York.

28


TABLE 8: Estimated number and age-adjusted proportional morbidity ratios,
PMR, and standard errors, S.E. (PMR), for white males employed in
occupations in the extraction of minerals, n.

mining industries (SIC 100-149) by disabling condition:

Security Disability Allowances, 1975-1976.

All disabling conditions

Infective & parasitic diseases
Tuberculosis
Pulmonary tuberculosis

Neoplasms
Malignant neoplasms
Digestive organs & peritoneum
Respiratory system
Bone, connective tissue,
& skin
Genital organs
Urinary organs
Other & unspecified sites
Neoplasms of lymphatic &
hematopoietic tissue
Sarcoma (lympho-,reticulo-),
other lymphomas
Leukemia
Neoplasms of unspecified nature

Endocrine, nutritional,
& metabolic diseases
Diabetes mellitus

Mental disorders
Schizophrenia
Neuroses
Alcoholism

Diseases of nervous system
& sense organs
Multiple sclerosis
Cataract
Glaucoma
Blindness

Diseases of circulatory system
Heart & hypertensive disease
Hypertensive disease
Ischemic heart disease

000-136
010-019
O11

140-239
140-199
150-159
160-163

170-173
180-187
188-189
190-199

200-209

200, 202
204-207
230-239

240-279
250

290-315
295
300
303

320-389
340
374
375
379

390-458
393-429
400-404
410-414

48

PMR

39
27

65

42°
120

24

e.c. (DOT 939) in

RK
aK
RK
RAK

ReK

aK
RE

RK
wR

kk

aK

kak

RAK

RK

kk

Social
1975-1976
SE(PMR) TOTAL
4199
24 21
14
14
6 166
6 124
9 28
11 45
11 2
10
14
24 25
28 40
15
20
2
13 51
12 27
8 235
13 51
19 93
20 6
8 141
4
10
1 1
14
4 927
5 784
21 42
5 702


rheumatoid arthritis was observed for both time periods; osteoarthritis
caused more disabilities than expected but this was statistically significant
only for 1969-73. More allowances were granted for displacement of
intervertebral disc (ICDA 725), slipped disc, than expected, but the
difference was statistically significant only for the 1975-76 data.

A statistically significant excess of disabilities due to accidents, poisoning
and violence occurred in the 1969-1973 data only. The PMR for 1975-76 was
greater than 100.0 but was not significant.

No disabilities were reported due to hearing loss.

None of the PMR's for disabling conditions for which there had not been a
previous report of a relationship were significant at the required 0.001 level.

Results by Specific Mining Occupations

Persons engaged in boring, drilling, cutting, and related occupations (DOT
930) exhibited a disability pattern generally consistent with that described
for all mining occupations. (Table 3). With the exception of a significantly
high PMR for respiratory system cancer for 1975-76, there were too few
blasters (DOT 931) to evaluate their disability pattern (N=282 for 1969-73 and
N=123 for 1975-76). Loaders and conveyors (DOT 932) exhibited the same basic
pattern of disability as for all mining occupations (Table 4). However,
accidents, poisoning and violence were significantly high in 1969-1973 but
were significantly low in 1975-76. There were too few disabilities awarded to
persons employed in crushing (DOT 933) and screening and related occupations
(DOT 934) to assess their disability patterns reliably. The basic pattern of
disability described for all mining occupations, (DOT 930-939) obtained for
other mining occupations (DOT 939) (Table 5). The PMR for silicotuberculosis
was significantly high in 1969-73, but the number of miners disabled from this
cause in 1975-76 did not fulfill the criterion to estimate a PMR. In the
earlier period the observed number of miners disabled from silicotuberculosis
was more than 11 times the expected number.

No previously unknown relationships were suggested by any of the analyses for
specific occupations

Mining Industry Analyses for 1975-76

The analysis was further restricted to mining occupations (DOT 930-939) within
the mining industry (SIC 100-149) (Table 6). This was possible for the
1975-76 data only. The pattern of disproportionately greater disability from
respiratory disease and musculoskeletal diseases was observed again. The
observed PMR for pneumoconiosis from silica and silicates was higher than for
the mining occupations not restricted to the mining industry ( see Table 2),
but not significantly so. The number of disabilities caused by
silicotuberculosis was smaller than the minimum established to estimate a

PMR. The PMR's for musculoskeletal system and connective tissue and

=14-


TABLE A~9 (Cont'd.)

1975-1976
ICDA PMR SE (PMR) TOTAL
Diseases of musculoskeletal
system & connective tissue 710-738 139 * 17 271
Rheumatoid arthritis 712 12 *e* ll 2
Osteoarthritis 713 144 41 92
Other & unspecified arthritis 710~711,
714-715 — 10
Displacement of intervertebral
disc 725 171 45 81
Congenital anomalies 740-759 — 7
Accidents, poisonings, & violence 800-999 143 43 88

--- The expected total number of disabled workers is less than 25 and the PMR is not
significant at the .001 level.
* The difference between PMR and 100 is statistically significant at the .05 level.
** The difference between PMR and 100 is statistically significant at the .01 level.
*** The difference between PMR and 100 is statistically significant at the -001 level.

81


TABLE 3 (Cont'd.)

1969-1973 1975-1976
ICDA PMR SE(PMR) TOTAL PMR SE(PMR) TOTAL

Diseases of nervous sytem

& sense organs 320-389 48 ** 15 159 82 23 90
Multiple sclerosis 340 -- 15
Cataract 374 226 128 25 -_ 2
Glaucoma 375 — 5
Blindness 379 -— 11 — 12
Diseases of circulatory
system 390-458 66 *** 5 1158 79 * 7 437
Heart & hypertensive
diseases 393-429 72 ** 7 971 81 * 8 357
Hypertensive disease 400-404 90 20 42 —- 36
Ischemic heart disease 410-414 70 ** 8 839 77 * 9 296
Cerebrovascular disease 430-438 41 #RR 9 98 53 22 32
Cerebral thrombosis &
embolism 433-434 45 * 22 24 —_ 7
Arteriosclerosis 440 45 ee 13 30 = 20
Diseases of respiratory
system 460-519 264 *** 16 1192 275 **® 28 356
Bronchitis & asthma 490-491,493 143 58 50 _ 36
Emphysema 492 245 **k 14 686 170 55 82
Pneumoconiosis & related
diseases 515-516 1498 ** 326 295 2323 *** 444 125
Pneumoconiosis due to
silica & silicates 515 1528 ** 328 295 2395 *** 451 125
Bronchiectasis 518 — 6 — 10
Diseases of digestive
system 520-577 51 *** 10 82 114 31 57
Peptic ulcer 531-533 —-- 5) — 20
Chronic enteritis &
ulcerative colitis 563 — 2
Cirrhosis of liver 571 — 28
Diseases of genitourinary
system 580-629 51 27 21 — 25
Nephritis & nephrosis 580-584 --- 7 _ 25
Chronic nephritis 582 _ 7 a 25
Other diseases of urinary
system 590-599 --- 10
Diseases of male genital
organs 600-607 --- 4

35


TABLE A-7: Estimated number and age-adjusted proportional morbidity ratios,
PMR, and standard errors, S.E. (PMR), for white males employed in
occupations in the extraction of minerals, n.e.c. (DOT 939) in
mining industries (SIC 100-149) by disabling condition other
than respiratory: Social Security Disability Allowances,

1975-1976.
1975-1976
ICDA PMR SE(PMR) TOTAL
All disabling conditions 2696
Infective & parasitic diseases 000-136 —> 7
Neoplasms 140-239 60 ** 10 166
Malignant neoplasms 140-199 53 ** 12 124
Digestive organs & peritoneum 150-159 54 ** 14 28
Respiratory system 160-163 52 * 20 45
Bone, connective tissue, &
skin 170-173 16 *** 17 2
Genital organs 180-187 a 10
Urinary organs 188-189 —< 14
Other & unspecified sites 190-199 70 36 25
Neoplasms of lymphatic &
hematopoietic tissue 200-209 117 39 40
Sarcoma (lympho-,reticulo-),
other lymphomas 200,202 — 15
Leukemia 204-207 — 20
Neoplasms of unspecified nature 230-239 — 2
Endocrine, nutritional, & metabolic
diseases 240-279 56 * 15 51
Diabetes mellitus 250 39 ** 17 27
Mental disorders 290-315 86 12 235
Schizophrenia 295 53 ** 13 51
Neuroses 300 166 * 28 93
Alcoholisn 303 _ 6
Diseases of nervous system & sense
organs 320-389 83 14 141
Multiple sclerosis 340 => 4
Cataract 374 — 10
Glaucoma 375 21 *** 2 1
Blindness 379 c= 14
Diseases of circulatory system 390-458 100 7 927
Heart & hypertensive disease 393-429 105 8 784
Hypertensive disease 400-404 114 40 42
Ischemic heart disease 410-414 108 9 702

76


TABLE 10: Estimated number and age-adjusted proportional morbidity ratios,
PMR, and standard errors, S.E. (PMR), for white males employed in
occupations in the extraction of minerals, n.e.c. (DOT 939) in
bituminous, lignite and anthracite coal mining (SIC 110-121) by

disabling condition: Social Security Disability Allowances,

1975-1976.

ICDA
All disabling conditions
Infective & parasitic diseases 000-136
Tuberculosis 010-019
Pulmonary tuberculosis 011
Neoplasms 140-239
Malignant neoplasms 140-199
Digestive organs & peritoneum 150-159
Respiratory system 160-163
Genital organs 180-187
Urinary organs 188-189
Other & unspecified sites 190-199
Endocrine, nutritional, &
metabolic diseases 240-279
Diabetes mellitus 250
Mental disorders 290-315
Schizophrenia 295
Neuroses 300
Alcoholism 303
Diseases of nervous system &
sense organs 320-389
Cataract 374
Diseases of circulatory system 390-458
Heart & hypertensive disease 393-429
Hypertensive disease 400-404
Ischemic heart disease 410-414
Cerebrovascular disease 430-438
Cerebral thrombosis & embolism 433-434
Arteriosclerosis 440
Diseases of respiratory system 460-519
Bronchitis & asthma 490-491 ,493
Emphysema 492

53

PMR

aK
ak

aK
RE

kk

RRK

kk

aK

kk

1975-1976
SE(PMR)

19

13
17
54

17

On

B
© co

38

51

TOTAL
1833

als}
10
10

52
52
5
16
5
5
21


TABLE A-7 (Cont'd.)

1975-1976
ICDA PMR SE (PMR) TOTAL
Cerebrovascular disease 430-438 98 27 98
Cerebral thrombosis & embolism 433-434 — 26
Arteriosclerosis 440 128 50 36
Diseases of digestive system 520-577 109 23 90
Peptic ulcer 531-533 — 33
Chronic enteritis &
ulcerative colitis 563 — 6
Cirrhosis of liver 571 63 26 26
Diseases of genitourinary system 580-629 = 23
Nephritis & nephrosis 580-584 — 8
Chronic nephritis 582 = 8
Other diseases of urinary system 590-599 — 15
Diseases of skin & sub-
cutaneous tissue 680-709 = 10
Diseases of musculoskeletal
system & connective tissue 710-738 160 *** 9 758
Rheumatoid arthritis 712 84 30 35
Osteoarthritis 713 179 * 31 274
Other & unspecified arthritis 710-711,
714-715 — 28
Displacement of intervertebral
disc 725 196 * 33 228
Congenital anomalies 740-759 60 22 17
Accidents, poisonings, & violence 800-999 172 * 27 269
Unknown or not classifiable a 2

~-- The expected total number of disabled workers is less than 25 and the PMR is not
significant at the .001 level.
* The difference between PMR and 100 is statistically significant at the .05 level.
** The difference between PMR and 100 is statistically significant at the .01 level.
*** The difference between PMR and 100 is statistically significant at the .001 level.

77


depressing effects of the huge PMR's for respiratory diseases, the high PMR’
for musculoskeletal system diseases, and perhaps that for accidents, poisoning
and violence as well. However, even when disabilities from respiratory
diseases were completely eliminated from the data significantly low PMR's for
these malignant neoplastic diseases (and others in some cases) were observed.

One tempting potential explanation does not seem reasonable when considered
more fully. This is the explanation that such diseases produce death too
rapidly for workers to apply for SSA disability benefits. While it is
certainly plausible, and it probably happens, such a phenomenon seems as
likely to occur for miners as for non-miners; hence, it probably (in terms of
present evidence) produces a constant effect across all industries and
occupations while the low PMR's reflect a variation from the norm. A constant
cannot account for a variable.

Another explanation, which is conjecture, is that there is "competition" for
causes of disabilities among disease conditions in terms of latency. Once a
worker receives a disability award for one disease, that worker does not get a
second award if he/she develops another disease. If the same exposures tend
to produce several different diseases then the diseases with the shortest
latencies will be the ones which cause disabilities. If this is true for
those most susceptible to diseases with long latencies, then such persons will
be removed from the workforce by disabilities from the diseases with the
shorter latencies before they have a chance to develop the competing diseases
with a longer latencies. If such hazards are not present for workers in other
occupations or industries, then among those workers the ones who are most
susceptible to the diseases with the longer latencies will develop such
diseases and become disabled. This could produce the negative PMR's for the
longer latency diseases in the first industries. Such a phenomenon may occur
for lung cancer and digestive system cancer relative to the mining industry.
Those workers who are at greatest genetic risk for such cancers may also be a
high risk for pneumoconiosis or emphysema, etc., and develop those diseases to
such an extent as to cause disability before they develop the cancers, unlike
workers with similar genetic characteristics in other occupations or
industries. To the extent that this speculation is accurate, then miners
disabled from respiratory disease, especially pneumoconiosis, maybe at higher
risk for subsequent lung cancer and digestive system cancer. Thus, follow-up
studies of such workers are recommended to determine their risks for malignant
neoplastic disease.

No conditions not previously considered related to mining work were found
associated with any of the mining occupations or mining industries analyzed in
this study.

Based on the results of this analysis, the following recommendations are
made: 1) Conduct follow-up studies of mine workers disabled from respiratory
diseases to determine subsequent morbidity and mortality from malignant
neoplasma as these persons may be at high risk; 2) Continue to monitor the
incidence of respiratory disease, especially pneumoconiosis, of miners with
surveillance data systems including both mortality data and morbidity data, to

22


ACKNOWLEDGMENTS

We thank Carol Burnett, Illness Effects Section, Surveillance Branch, NIOSH,
for major assistance in the literature review, revisions, and numerous
readings to help us prepare the final draft. The following staff members made
important contributions in the preparation of this report: Audrey B. Coe,
SSA, who supervised data compilation from SSA master files, Jerome H. Green,
SSA, and Paula Franklin, SSA. Other staff members who made significant
contributions during the preparation of this report were John P. Sestito,
Chief, Illness Effects Section, Todd M. Frazier, Chief, Surveillance Branch,
NIOSH, and Aaron Krute, Director, Division of Disability Studies, SSA.

With thanks, we acknowledge Lois L. Schuster, Sharon Jenkins,
Corliss R. Straus, Jewel J. Evans, and Judith A. Neyer, NIOSH, for their
efforts in providing typing and other clerical support.

A special acknowledgment of gratitude for her support goes to Alice.


TABLE 4: Estimated number and age-adjusted Proportional morbidity ratios, PMR
and standard errors, S.E.(PMR), for white males employed in loading
and conveying occupations (DOT 932) by disabling condition: Social
Security Disability Awards, 1969-1973, and Allowances, 1975-1976.

1969-1973 1975-1976
ICDA PMR SE(PMR) TOTAL PMR SE(PMR) TOTAL
All disabling conditions 2217 804
Infective and parasitic
diseases 000-136 35 3100615 —- 5
Tuberculosis 010-019 51 42 15 _ 5
Pulmonary tuberculosis 011 58 49 15 = 5
Neoplasms 140-239 46 *** 86899 32 ** 618 25
Malignant neoplasms 140-199 34 #** 8 61 38 * 20 25
Buccal cavity & pharynx 140-149 --- 6
Digestive organs &
peritoneum 150-159 12 **e 9 5 = 10
Respiratory system 160-163 52 * 19) 35)
Bone, connective tissue,
& skin 170-173 --- 5
Urinary organs 188-189 --- 4
Other & unspecified
sites 190-199 22 **k «615 60 -— 15
Neoplasms of lymphatic &
hematopoietic tissue 200-209 132 70 38

Sarcoma (lympho-,
reticulo-), other

lymphomas 200,202 ~--- 6
Leukemia 204-207 -~- 10
Endocrine, nutritional, &
metabolic diseases 240-279 = 53 21 36 -—— 25
Diabetes mellitus 250 63 270 320 20
Diseases of blood & blood-
forming organs 280-289 = 10
Mental disorders 290-315 75 11165 58 20 40
Schizophrenia 295 69 22, 60 —— 5
Neuroses 300 69 26 270 =~ 5
Alcoholism 303 — 15
Diseases of nervous system &
sense organs 320-389 32 *** 10 42 67 33 32
Glaucoma 375 > 6 5
Blindness 379 > j => 5

37


A-9 Estimated number and age-adjusted proportional morbidity
ratios, PMR, and standard errors, S.E.(PMR), for white
males employed in occupations in the extraction of minerals,
n.e.c. (DOT 939) in bituminous, lignite, and anthracite
coal mining (SIC 110-121) by disabling condition other than
respiratory: Social Security Disability Allowances,
1975-1976 6 6 we ee

A-10 Estimated number and age-adjusted proportionate morbidity
ratios, PMR, and standard errors, S.E.(PMR), for white
males employed in extraction of minerals (DOT 930-939) in
oil and gas extraction industries (SIC 130-138) by disabling
condition other than respiratory: Social Security Disability
Allowances, 1975-1976 2. 1 6 6 ww ee ww ee eee we

A-11 Estimated number and age-adjusted proportionate morbidity
ratios, PMR, and standard errors S.E.(PMR), for white
males employed in boring, drilling, cutting, and related
occupations (DOT 930) in oil and gas extraction industries
(SIC 130-138) by disabling conditions other than respiratory:
Social Security Disability Allowances, 1975-1976 .......

A-12 Estimated number and age-adjusted proportionate morbidity
ratios, PMR, and standard errors, S.E.(PMR), for white
males employed in extraction of minerals (DOT 930-939) in
metal mining and non-metallic minerals (SIC 100-109, 140-149)
by disabling conditions other than respiratory: Social
Security Disability Allowances, 1975-1976 . 2... 2. 2 2 se we

ix

80

82

84

86


TABLE 2: Estimated number and age-adjusted proportional morbidity ratios, PMR,
and standard errors, S.E.(PMR), for white males employed in the
extraction of minerals (DOT 930-939) by disabling condition: Social
Security Disability Awards, 1969-1973, and Allowances, 1975-1976.

1969-1973 1975-1976
ICDA PMR SE(PMR) TOTAL PMR SE(PMR) TOTAL
All disabling conditions 23854 7330
Infective and parasitic
diseases 000-136 =77 * 8 332 56* 19 40
Tuberculosis 010-019 98 13 287 93 34 33
Silicotuberculosis 010 958 * 303 39 = 2
Pulmonary tuberculosis 011 87 12 220 110 38 31
Neoplasms 140-239 9-47 -**k 2 1104 49 #RK 7 341
Malignant neoplasms 140-199 46 *** 4 909 47 Rk 9 (274
Buccal cavity & pharynx 140-149 45 ** 13 55 32 * 23 10
Digestive organs &
peritoneum 150-159 37 eK 8 170 30 *ee 8 40
Respiratory system 160-163 52 *** 6 392 53 *** 10 116
Bone, connective
tissue, & skin 170-173 48 23 44 38 50 12
Genital organs 180-187 51 * 19 67 92 44 40
Urinary organs 188-189 37 ** 16 46 40 * 22 14
Other & unspecified
sites 190-199 47 *** = 10 135 47 * 23 42
Neoplasms of lymphatic &
hematopoietic tissue 200-209 53 ** 13 158 72 20 61

Sarcoma (lympho-,
reticulo-), other

lymphomas 200,202 56 * 17 51 57 *eR 4 15
Leukemia 204-207. 57 26 42 100 40 25
Benign neoplasms 210-228 821 *** = 9 15 *** 19 2
Neoplasms of unspecified
nature 230-239 91 53 28 _ 4
Endocrine, nutritional, &
metabolic diseases 240-279 54 *** 7 402 41 eRR 7 92
Diabetes mellitus 250 51 *** 9 282 32 #kk 8 56
Diseases of blood & blood-
forming organs 280-289 123 31 49 — 10
Mental disorders 290-315 65 *** 2 1391 67 ** 8 451
Schizophrenia 295 44 RK 5 342 57 * 17 136
Neuroses 300 110 7 432 116 16 ©6160
Alcoholism 303 39 *ee 12 56 14 *ek 13 6

31


PMR's were estimated for all occupation, industry, and disease combinations
for which the expected number of disabled workers for the U.S., the
denominator of the PMR, was 25 or more. This procedure tends to ensure that
the standard errors were useful guides to the precision of the PMR's. If the
expected number was less than 25, a PMR was presented only if the expected
number was at least 5 and the PMR was statistically significantly different
from 100 at the .001 level using the two-tailed test described by NIOSH (DHHS ,
1980). This modification was motivated by the objective to present a maximum
of reliable information. It was based on an asymptotic approximation to
Chebyshev's Inequality (Wilks, 1963). Extreme but reliable PMR's were not
ignored. The presence of "---" indicates that neither of the criteria just
described were fulfilled and the PMR was not estimated.

PMR's presented in this report were estimates of national values and were
subject to sampling error. Estimates of the standard errors of these PMR's
are presented so that the risk of various magnitudes of sampling error may be
determined. Estimation of the standard errors of the PMR's is complicated by
the fact that the PMR estimators are ratios and there is no known expression
for the standard error. This was overcome by the use of a sample replicate
procedure (see DHHS, 1980).

The appearance of one, two, or three asterisks after the values of the PMR's
presented in this report represents the outcome of the F-test described by
NIOSH (DHHS, 1980). A single asterisk indicates that the difference was
statistically significant at the five percent level, two asterisks indicate
statistical significance at the one percent level, and three asterisks
indicate statistical significance at the 0.001 level. No asterisk appears if
the estimated PMR does not differ from 100 by a statistically significant
amount.

-10-


MATERIALS AND METHODS

NIOSH/SSA Disability Data File

The source of data for this report was a statistically selected sample of
records for persons determined to be eligible for SSA disability benefit
awards for the years 1969 through 1973 and 1975 and 1976. Once SSA determines
a worker to be eligible for disability benefits, that worker remains eligible
until he/she is no longer disabled, dies, or becomes age 65. Thus, these are
incidence data. These records were obtained for routine administration of the
disability program. To support its own research, SSA selected a sample of
these administrative records each year using a stratified random sampling plan
with states as strata. Sampling rates varied by state and from year to year.
The sampling rate was made inversely proportional to the total awards for the
previous year. However, the overall sampling rate was approximately 20
percent. NIOSH has obtained a subset of this dataset for occupational health
research, The NIOSH dataset includes age, race, sex, diagnosis of primary
disabling condition, occupation, and industry (1975-1976 only). Detailed
information about the NIOSH-SSA disabled worker dataset, statistical inference
methods developed for its analysis, and measures of proporticnal morbidity
have been presented elsewhere (DHHS, 1980)

Age refers to age at the date of eligibility for a benefit award. Workers
were grouped into 5-year intervals for those aged 40 to 64. The remaining
workers fall into two age groups--those under 40 years and those over 64 years
(the last group includes workers age 65 and older at the time they were
awarded benefits for disabilities that occurred before they became 65). Race
was categorized by SSA as black, white, other, or unknown; however, because
there were few nonwhite and female miners, the analysis was restricted to
white men.

The disabling condition was the condition diagnosed as the primary cause of
the worker's disability. Disabling conditions were coded by SSA coders
according to the Eighth Revision of the International Classification of
Diseases Adapted for Use in the United States (ICDA) (U.S. Department of
Health, Education, and Welfare, 1968). Coding was done in terms of three
digit categories of the ICDA. The categories for disabling conditions used in
this report have been chosen for relevance to the surveillance objectives of
this study. The categories are shown in Table 1.

Occupation represents the disabled worker's longest full-time occupation in
the 10 years preceding the date of the disability. It was coded according to
the occupational classification in the Dictionary of Occupational Titles (DOT)
(U.S.Department of Labor, 1965). The occupations classified under 930-939,
Extraction of Minerals, were compared to all other occupations combined.
Specific categories included were:

930 Boring, Drilling, and Cutting
931 Blasting

932 Loading and Conveying

933 Crushing


Estimated number and age-adjusted proportional morbidity
ratios, PMR, and standard errors, S.E.(PMR), for white males
employed in boring, drilling, cutting, and related occupations
(DOT 930) by disabling condition: Social Security Disability
Awards and Allowances, 1969-1973, 1975-1976... .....24.4.4

Estimated number and age-adjusted proportional morbidity
ratios, PMR, and standard errors, S.E.(PMR), for white males
employed in loading and conveying occupations (DOT 932) by
disabling condition: Social Security Disability Awards

and Allowances, 1969-1973, 1975-1976 . 2... 2 ee wee eee

Estimated number and age-adjusted proportional morbidity
ratios, PMR, and standard errors, S.E.(PMR), for white males
employed in occupations in the extraction of minerals, n.e.c.
(DOT 939) by disabling condition: Social Security Disability
Awards and Allowances, 1969-1973, 1975-1976 .........

Estimated number and age-adjusted proportional morbidity
ratios, PMR, and standard errors, S.E.(PMR), for white males
employed in the extraction of minerals (DOT 930-939) in

mining industries (SIC 100-149) by disabling condition:

Social Security Disability Allowances, 1975-1976 .......

Estimated number and age-adjusted proportional morbidity
ratios, PMR, and standard errors, S.E.(PMR), for white

males employed in boring, drilling, cutting, and related
occupations (DOT 930) in mining industries (SIC 100-149)

by disabling condition: Social Security Disability
Allowances, 1975-1976 . 2 1 6 6 we ee eee ee ee

Estimated number and age-adjusted proportional morbidity
ratios, PMR, and standard errors, S.E.(PMR), for white

males employed in occupations in the extraction of minerals,
n.e.c. (DOT 939) in mining industries (SIC 100-149) by
disabling condition: Social Security Disability Allowances,
1975-1976 6 6 6 ww ee we ee ee we ew

Estimated number and age-adjusted proportional morbidity
ratios, PMR, and standard errors, S.E.(PMR), for white

males employed in extraction of minerals (DOT 930-939) in
bituminous, lignite, and anthracite coal mining (SIC

110-121) by disabling condition: Social Security Disability
Allowances, 1975-1976 . 2 2 21 2 ee ee ee ee ew we ww

vi

34

37

39

43

46

48

51


TABLE 13 (Cont'd.)

1975-1976
ICDA PMR SE(PMR) TOTAL
Diseases of digestive system 520-577 -—_ 15
Peptic ulcer 531-533 — 10
Cirrhosis of liver 571 — 5
Diseases of genitourinary system 580-629 — 7
Nephritis & nephrosis 580-584 — 7
Chronic nephritis 582 one 7
Diseases of skin & sub-
cutaneous tissue 680-709 — 5
Diseases of musculoskeletal
system & connective tissue 710-738 102 28 68
Rheumatoid arthritis 712 — 5
Osteoarthritis 713 — 23
Other & unspecified arthritis 710-711,
714-715 — 7
Displacement of intervertebral
disc 725 — 5
Accidents, poisonings, & violence 800-999 — 33

--- The expected total number of disabled workers is less than 25 and the PMR is not
significant at the .001 level.

* The difference between PMR and 100 is statistically significant at the .05 level.
** The difference between PMR and 100 is statistically significant at the .01 level.
**k The difference between PMR and 100 is statistically significant at the .001 level.

60


displacement of an intervertebral disc were significantly greater than 100.0
while that for osteoarthritis was greater than 100.0 but was not significant.
Significantly low PMR's were noted for the following diseases: cancer of the
respiratory system, cancer of the digestive organs and peritoneum, rheumatoid
arthritis, all neoplasms, and diseases of the circulatory system. This
pattern was also similar to that for all mining occupations not restricted to
mining industry. The PMR for accidents, poisoning and violence was greater
than 100.0 but was not significant.

Persons employed in boring, drilling, cutting, and related occupations (DOT
930) in mining industries experienced increased disability only from
respiratory diseases, specifically all pneumoconioses and silicosis, and
displacement of intervertebral disc (slipped disc) (Table 7). All disability
allowances for pneumoconiosis were due to silica and silicates. A
significantly low PMR was noted for cancer of the digestive organs and
peritoneum.

Again, too few blasters (DOT 931) were awarded disability to permit detailed
evaluation of their disability pattern (N=109). Significant excess of
respiratory system cancer and deficits of heart and hypertensive disease and
of musculoskeletal disease relative to expected numbers were noted. Persons
employed in loading and conveying occupations (DOT 932) experienced excess
disability from diseases of the respiratory system. Deficits of disability
were observed for accidents, poisoning, and violence and all neoplasms. Too
few men employed in crushing and screening occupations received disability to
evaluate the PMR's.

With the exception of musculoskeletal disease, persons employed in other
mining occupations (DOT 939) followed the general pattern of disability
exhibited by all mining occupations (DOT 930-939) (Table 8). Contrary to the
general pattern of disability, the proportion of disabilities due to diseases
of the musculoskeletal system was not significantly high.

None of the PMR's for disabilities from diseases not subjected to planned

tests were significant for the mining industry as a whole, for any specific
mining industry, or for any mining occupation within it that was studied.

Specific Mining Industry Analyses

Disabilities of men engaged in mining occupations (DOT 930-939) in the
bituminous, lignite, and anthracite coal mining industry (SIC 110-121) were
distributed in a pattern consistent with that described for all mining
industries (Table 9). The PMR for pneumoconiosis due to silica and silicates
for this occupation/industry was higher than for any considered except for
workers in the same industry restricted to “other” mining occupations as
described below. The corresponding ratio of observed cases to expected was
nearly 49 as the PMR was 4894, There was a significant deficit, relative to
the expected number, of disabilities due to circulatory system disease and to
rheumatoid arthritis. There were too few cases to estimate the PMR for peptic


LITERATURE REVIEW

Working conditions in the mining industry can be hazardous to health and
safety. These conditions produce illness, injury, and death and may be
classified into seven general types of hazard: 1) safety hazards that cause
injuries, 2) high levels of dust, 3) extremes of temperature and humidity,
4) noise and vibration, 5) gases, fumes, and smoke, 6) demanding physical
labor including repetitive low level trauma, and 7) ionizing radiation.

Demanding physical labor is a characteristic of the modern mining industry,
despite intensive mechanization. Many underground mining occupations require
working in close quarters with large pieces of equipment, especially in low
coal seams — some as low as 22 inches in height (Dadisman, 1970). Occupations
such as blasting and drilling involve kneeling and stooping for long periods
of time. These physical stresses may place the miner at increased risk of
disabling injury.

In addition to risks of occupational origin, persons employed in the mining
industry may be at increased risk of certain disabilities due to lifestyle.
Particularly significant is the high prevalence of cigarette smoking. Data
collected by the Health Interview Survey (1972) estimate that 72 percent of
miners are current or ex-smokers and 28 percent are non-smokers.
Corresponding estimates for non-miners are 56 percent and 44 percent,
respectively. Patterns of tobacco consumption by miners reported elsewhere
agree closely with the Health Interview Survey estimate (Higgins, et al.,
1981; Enterline and Lainhart, 1967). However the proportion of smokers in
comparison groups of nonminers is generally much higher than that reported by
the Health Interview Survey. Tobacco smoking has been linked to lung cancer,
cardiovascular disease, and respiratory disease, especially emphysema; a high
proportion of disabilities among miners might be expected to be due to these
diseases.

In a study of morbidity in 40 industries, the mining industry ranked in the
lowest quartile for the following measures of morbidity: days of restricted
activity, days of bed disability, days of work lost, and number of doctor
visits (Kaminski and Spirtas, 1980). The age-adjusted proportion of persons
employed in the mining industry having one or more work injuries was the same
as that of the total working population (2 percent).

The rate of injuries in the mining industry has been declining steadily (U.S.
Bureau of the Census, 1980). From 1965 to 1978, a period of increasing
employment in the mining industry, the fatal accident rate for coal mining
declined from 1.0 to 0.3 per million work-hours while that for all other
mining declined from 1.4 to 0.5. Nonfatal accidents for coal mining declined
from 45 to 38 per million work-hours while that for all other mining declined
from 92 to 56. The fatal accident rate for mining and quarrying was the
highest among all major industry groups in 1978 (63 per 100,000 miners); for
all industries combined, the rate was 14 per 100,000. The 1978 nonfatal


In addition to higher relative incidence of disabilities caused by
pneumoconiosis, workers in the mining industry also experience higher relative
incidence of other chronic respiratory diseases. In fact, in contrast to most
non-mining occupations (DHHS, 1980), respiratory diseases were the leading
cause of disabilities rather than diseases of the circulatory system. The
disability pattern discovered was consistent with the studies of mortality and
morbidity previously summarized. The number of disability awards or
allowances for emphysema and bronchitis and asthma was significantly higher
than expected in those occupation and industry groups where the PMR was based
on enough cases to provide reasonable power for statistical tests against
reasonable alternatives.

The leading cause of disability for miners for 1969-73 among all disease
rubrics analyzed was emphysema. One factor associated with emphysema is
smoking. This may be the source of the emphysema caused disabilities found in
this study. However, this relationship may result from the combined effects
of smoking and dust, or other factors not yet understood. Only one disease is
selected by SSA as the primary cause of disability for a disability award.
This is the cause of disability analyzed in this report. In fact, more than
one disease condition may contribute to a worker's impairment. Many of the
workers disabled by emphysema may also have had pneumoconiosis, and vice versa
so that these results may underestimate the incidence of both conditions.

Tuberculosis was not found to be a cause of higher relative incidence of
disability in either period but silicotuberculosis was for the 1969-73 period
but not for the 1975-76 period. This may reflect better control of this
disease or changes in diagnosis.

Nerve deafness and musculoskeletal disease are often trauma~induced diseases
of the mining industry. Although much of the equipment used in mining is
noisy, especially when sound is confined underground, there were no
disabilities awarded for hearing loss. There are several possible
explanations for this: 1) Nerve deafness is not perceived as a disabling
condition and compensation is not sought; 2) When hearing loss is first
detected, the miner is transferred to a quieter environment, thus limiting
hearing loss; or 3) The impairment is not severe enough to result in inability
to have employment.

Except for the possible changes previously discussed, the general pattern of
disability observed in mining occupations was consistent across the two time
periods, 1969-1973 and 1975-1976. The larger sample size of the dataset for
the earlier period permitted a more detailed analysis of disabling conditions
than was possible for the later period. Respiratory diseases caused
significant excess disability among miners in all occupations and individual
occupations. Pneumoconiosis due to silica and silicates, bronchitis and
asthma, and emphysema were causes of significant excess disability;
bronchiectasis was not.

The pattern of disability observed in the oil and gas extraction industry was

different from that observed in most other mining industries. Nonmalignant
respiratory disease, primarily pneumoconiosis, caused most of the disability

20


DEPARTMENT OF HEALTH AND HUMAN SERVICES
PUBLIC HEALTH SERVICE
CENTERS FOR DISEASE CONTROL
NATIONAL INSTITUTE FOR OCCUPATIONAL SAFETY AND HEALTH
ROBERT A. TAFT LABORATORIES
4676 COLUMBIA PARKWAY, CINCINNATI, OHIO 45226

OFFICIAL BUSINESS
PENALTY FOR PRIVATE USE. $300

Redistribution using indicia is illegal.

Special Fourth Class -Book

POSTAGE AND FEES PAID
U.S. DEPARTMENT OF HHS
HHS 396

DHHS (NIOSH) Publication No. 85-105


TABLE A~10: Estimated number and age~adjusted proportional morbidity ratios,
PMR, and standard errors, S.E. (PMR), for white males employed
in extraction of minerals (DOT 930-939) in oil and gas
extraction industries (SIC 130-138) by disabling condition

Social Security Disability Awards,

other than respiratory:

1975-1976.

All disabling conditions

Neoplasms
Malignant neoplasms
Respiratory system
Genital organs
Neoplasms of lymphatic &
hematopoietic tissue

Endocrine, nutritional, &
metabolic diseases
Diabetes mellitus

Mental disorders
Schizophrenia
Neuroses

Diseases of nervous system &
sense organs
Multiple sclerosis
Blindness

Diseases of circulatory system
Heart & hypertensive disease
Ischemic heart disease
Cerebrovascular disease
Arteriosclerosis

Diseases of digestive system
Chronic enteritis &
ulcerative colitis
Cirrhosis of liver

Diseases of musculoskeletal
system & connective tissue
Osteoarthritis
Displacement of inter-

vertebral disc

140-239
140-199
160-163
180-187

200-209

240-279
250

290-315
295
300

320-389
340
379

390-458
393-429
410-414
430-438
440
520-577
563
571
710-738
713

725

82

PMR

184 *
202

416 *

1975-1976

SE(PMR) TOTAL

626

32 34

29 25

21

4

9

12

12

31 26

63 6

6

50 59

10

14

19 215

22 170

25 168

26

10

22

2

20

32 201

55 71

101 113


accident rate in the mining industry was more than twice that for all other
industries (5040 vs. 2369 per 100,000).

Several population-based studies in the United States and England have
described morbidity and mortality associated with the mining industry.
Guralnick (1963), using a sample of U. S. 1950 death certificates, cited high
rates for tuberculosis, respiratory diseases, malignant neoplasms of the
stomach, other myocardial degeneration, arteriosclerosis and accidents for
coal miners. Crude petroleum and natural gas extraction workers exhibited
high risks for coronary artery disease and accidents. Reports of the
Registrar General (1957, 1971) for England and Wales, 1951 and 1961, showed
high rates for tuberculosis, respiratory diseases, malignant neoplasms of the
stomach and accidents for mineworkers. Myocardial degeneration was also high
in the 1951 report. In addition to these findings, mine operatives and
laborers were reported to have disproportionately high lung cancer in a
Washington State mortality study for 1950-1979 (Milham, 1983). Oil well
drillers exhibited high risks for only respiratory diseases.

NIOSH conducted a survey of cancer morbidity in relation to occupation for the
years 1956 to 1965 using data from Roswell Park Memorial Institute, a major
cancer treatment center in Buffalo, N. Y. (Decoufle, et al., 1977). No
increased risks were detected for mine operatives and laborers. Disability
insurance benefit awards made in 1959-1962 to men under age 65 showed higher
proportional morbidity ratios (PMR's) for tuberculosis with occupational
disease of lung, pneumoconiosis and other respiratory diseases, and
musculoskeletal diseases (Public Health Service, 1967).

An excess of risk of respiratory cancer mortality was reported in European
miners exposed to high levels of airborne radon and radon daughters (Hueper,
1942). In a mortality study of uranium miners and millers, significant excess
mortality was reported in white male miners with over 5 years underground
mining experience (Wagoner et al., 1964;). Causes of excess mortality were:
respiratory cancer (10-fold), “all other causes" (2.1-fold), and accidents
(3-fold). Excess mortality from “all other causes” was a reflection of
pulmonary fibrosis and its complications; 75 percent of the fatal accidents
occurred in the uranium mines. Cooper (1968) noted that the increased
incidence of lung cancer experienced by underground uranium miners was
characterized by the predominance of undifferentiated cell types, a younger
than average patient age, and rapid fatality. No excess respiratory cancer
deaths were reported at less than 5 years after onset of underground uranium
mining (Lundin, et al., 1969). Ten years after onset of mining, all exposure
levels had elevated rates.

A dose-response relationship was reported between the incidence of respiratory
cancer mortality and duration of underground uranium mining exposure (Wagoner
et al., 1965). This curve was linear in nonsmokers; smoking elevated and
distorted the curve (Archer et al., 1976). This is consistent with the
approximately 10-fold increase in risk of respiratory cancer among smoking
uranium miners compared with nonsmoking miners (Lundin et al., 1969). Archer
et al. (1976) observed a linear dose-response curve between mine radiation
‘exposure and respiratory disease mortality (noncancer) in nonsmoking miners.




TABLE 11 (Cont'd.)

1975-1976
ICDA PMR SE(PMR) TOTAL
Congenital anomalies 740-759 — 10
Accidents, poisonings, & violence 800-999 119 26 46
Unknown or not classifiable 1

--- The expected total number of disabled workers is less than 25 and the PMR is not
significant at the .001 level.

* The difference between PMR and 100 is statistically significant at the .05 level.
*k The difference between PMR and 100 is statistically significant at the .01 level.
*kk The difference between PMR and 100 is statistically significant at the .001 level.

56


Diseases of nervous system &
sense organs
Multiple sclerosis
Cataract
Glaucoma
Blindness

Disease of circulatory
system
Heart & hypertensive
disease
Hypertensive disease
Ischemic heart disease
Cerebrovascular disease
Cerebral thrombosis &
embolism
Arteriosclerosis

Diseases of digestive system
Peptic ulcer
Chronic enteritis &
ulcerative dolitis
Cirrhosis of liver

Diseases of genitourinary

system

Nephritis & nephrosis
Chronic nephritis

Other diseases of urinary
system

Diseases of male genital
organs

Diseases of skin & sub-
cutaneous tissue

Diseases of musculoskeletal
system and connective
tissue
Rheumatoid arthritis
Osteoarthritis
Other & unspecified
arthritis
Displacement of inter-
vertebral disc

TABLE A-1 (Cont'd.)

ICDA

320-389
340
374
375
379

390-458

393-429
400-404
410-414
430-438

433-434
440

520-577
531-533

563
571

580-629
580-584
582

590-599

600-607

680-709

710-738
712
713
710, 711
714-715

725

SE(PMR) TOTAL

1969-1973
PMR
68 #ee 66
16 **e 14
159 7
84 35
86 25
91 * 3
98 3
149 25
95 4
50 #ee G
65 22
94 22
79 ** 6
138 26
76 12
52 30
61 34
84 31
142 25
143 #eR OS
94 7
175 *** 10
161 37
150 ** 14

62

711
15
59
25
44

5431
4502
235
3870
405

118
216

412
112

98
35
35
44

19

79

3652
313
1377
167

1062

1975-1976
PMR SE(PMR)
86 uu
100 5
102 6
130 29
103 6
93 v7
104 64
136 33
114 20
93 26
131 38
163 **k 9
61 21
174 ** 22
107 38
209 *** 20

TOTAL

281
19
12

6

31
1714
1408
90
1241
174

33
71

176
58

8
71

53
38
38

15

30

1453
498
39
464


The characteristics of the SSA disability benefit program, as it existed at
the time applicable for the study population of this report, have been
described in the literature (SSA, 1982; SSA, 1971; Popick, 197la; Popick,
1971b, Popick, 1971c).

A worker applies for disability benefits at any office of SSA. The worker's
eligibility for benefits is determined by SSA while the medical determination
of the existence of a physical or mental impairment that has lasted or will
last at least 12 months or be terminal is accomplished by a state agency, such
as a state vocational rehabilitation agency. SSA.reviews the findings of the
state agency regarding the medical basis for the worker's claim and the
technical eligibility of the worker for SSA benefits in accordance with SSA
rules and regulations. If the worker's remaining capacity to perform physical
and mental activities ". . . falls short of the demands of jobs he could
reasonably be expected to perform, he is considered disabled. . . ."
(Popick,1971b). The worker's claim is regarded as "allowed", or his/her case
is termed “an allowance", if the SSA review determines that the worker .
fulfills the requirements for a cash benefit for his/her disability. Workers
may appeal a disallowance of their claims. If a worker whose claim is allowed
is then judged newly entitled to monthly cash benefits, his/her case is termed
an award (SSA, 1982). The NIOSH disability file has data from a sample of the
awards for the period from 1969 to 1973 and from a sample of allowances for
the period from 1975 to 1976. Allowances and awards are nearly equivalent.

Allowances almost always automatically become awards but workers receiving
allowances may not receive cash benefits (awards), or be considered a new
entitlement, under some conditions which occur relatively infrequently. Among
these conditions are the following: (1) The beneficiary's name is unknown;
(2) The address of the beneficiary is unknown; (3) Previous overpayment of
benefits; (4) The disability is a continuation of one previously associated
with an award (only after the worker had recovered sufficiently to return to
work and his/her impairment recurs within five years, see Popick,197la); and
(5) Benefits from workers’ compensation, government pensions, and/or other
public assistance programs exceed 80 percent of previous earnings while the
worker was employed. While allowance data appear more suitable for
occupational epidemiological study (because award data do not include some
cases which would seem informative), it does not appear that the differences
would have noticable effects on analyses.

Both award and allowance data are incidence data as a worker's eligibility for
SSA benefits continues until the worker is no longer disabled, dies, or
becomes eligible for SSA retirement benefits (Popick, 197la).

Various characteristics of the SSA disability benefit program and its
utilization by workers both enhance and reduce the usefulness of these data on
awards or allowances for occupational health research.

Characteristics which argue for the validity of these data for occupational
health research are: (1) Cash monthly benefits serve as an incentive for
workers with impairments to apply for benefits; (2) Physicians make
determinations of disabling conditions using medical evidence (but this may


If individuals with mining related hearing loss remain employed, possibly in
mining occupations not requiring hearing acuity, disability awards caused by
hearing loss will not occur. However, the PMR's were estimated for those
mining industries or occupations in which such disabilities occurred .

Different patterns of disability may occur among surface and underground
miners. The industry code did not provide information on whether a given
mining industry was surface or underground; it was not possible to separate
disability patterns by depth of mine.

Significantly elevated PMR's were expected for all mining industry and
occupations for the following disease categories:

tuberculosis (ICDA 010-019)
silicotuberculosis (ICDA 010)
malignant neoplasms of the digestive organs and peritoneum (ICDA 150-159)
malignant neoplasms of the respiratory system (ICDA 160-163)
diseases of the circulatory system (ICDA 390-458)
hearing loss
bronchitis and asthma (ICDA 490-491, 493)
emphysema (ICDA 492)
pneumoconiosis due to silica and silicates (ICDA 515)
bronchiectasis (ICDA 518)
peptic ulcer (ICDA 531-533)
rheumatoid arthritis (ICDA 712)
osteoarthritis (ICDA 713)
displacement of an intervertebral disc (ICDA 725)
accidents, poisonings, and violence (ICDA 800-999)

The data for 1969-73 were analyzed separately from that for 1975-76. The main
reason was that industry codes were available for the latter period but not
the first. Furthermore, the 1969-73 data are award data while those for
1975-76 are allowance data even though this difference may be of little
epidemiological significance. Finally, this division would permit detection
of change in relationships over time, at least for all mining occupations as a
whole. The dataset for the two years, 1975 and 1976, should provide sufficient
statistical power for separate analyses, but adding the 1975-76 dataset to the
dataset for 1969-73 would not markedly increase power for the occupational
analyses of the 1969-73 dataset.

-12-


TABLE 5 (Cont'd.)

1969-1973 1975-1976
ICDA PMR SE(PMR) TOTAL PMR SE(PMR) TOTAL

Diseases of nervous system &

sense organs 320-389 56 *** 7 503 62 **k 8 161
Multiple sclerosis 340 22 ** = =20 15 — 4
Cataract 374 94 42 34 — 14
Glaucoma 375 67 28 19 13 **k 1 1
Blindness 379 68 42 30 o> 14
Diseases of circulatory
system 390-458 65 *** 2 3693 69 *** 4 1027
Heart & hypertensive
disease 393-429 70 *** 1 3045 73 **k 4 861
Hypertensive disease 400-404 94 20 141 71 19 42
Ischemic heart disease 410-414 68 *** = 3 2651 75 #RR 5 774
Cerebrovascular disease 430-438 30 *** 3 236 69 16 «112
Cerebral thrombosis &
embolism 433-434 46 *** 11 80 95 41 26
Arteriosclerosis 440 80 20 182 79 21 36
Diseases of respiratory
system 460-519 385 *** 6 5808 440 *k* 21 1535
Bronchitis & asthma 490-491,493 215 ** 27 241 232 71 92
Emphysema 492 328 *** = 6 = 3123 327 *** 39° (425
Pneumoconiosis & related
diseases 515-516 2514 *** 89 1668 3542 *** 35] 532
Pneumoconiosis due to
silica & silicates 515 2565 *** 91 1668 3643 *** 361 532
Bronchiectasis 518 — 6 — 7
Diseases of digestive
system 520-577. --- 6 80 17-102
Peptic ulcer 531-533 115 18 86 — 33
Chronic enteritis &
ulcerative colitis 563 — 6
Cirrhosis of liver 571 57 21 36
Diseases of genitourinary
system 580-629 59 * 17 63 71 48 23
Nephritis & nephrosis 580-584 36 32 19 — 8
Chronic nephritis 582 43 35 19 a 8
Other diseases of urinary
system 590-599 74 36 34 — 15
Diseases of male genital
organs 600-607  -~- 10

41


TABLE A-12: Estimated number and age-adjusted proportional morbidity ratios,
PMR, and standard errors, S.E. (PMR), for white males employed
in extraction of minerals (DOT 930-939) in metal mining and
nonmetallic minerals (SIC 100-109, 140-149) by disabling

condition other than respiratory:

Allowances, 1975-1976.

All disabling conditions

Neoplasms
Malignant neoplasms
Respiratory system
Bone, connective tissue, &
skin
Urinary organs
Other & unspecified sites
Neoplasms of lymphatic &
hematopoietic tissue
Leukemia
Neoplasms of unspecified nature

Mental disorders
Schizophrenia

Diseases of nervous system &
sense organs
Multiple sclerosis
Glaucoma

Diseases of circulatory system
Heart & hypertensive disease
Hypertensive disease
Ischemic heart disease
Cerebrovascular disease
Cerebral thrombosis & embolism
Arteriosclerosis

Diseases of digestive system
Peptic ulcer
Cirrhosis of liver

Diseases of genitourinary system
Nephritis & nephrosis
Chronic nephritis

Diseases of skin & sub-
cutaneous tissue

ICDA

140-239
140-199
160-163

170-173
188-189
190-199

200-209
204-207
230-239

290-315
295

320-389
340
375

390-458
393-429
400-404
410-414
430-438
433-434
440

520-577
531-533
571

580-629

580-584
582

680-709

86

PMR

1975-1976
SE(PMR)

46

46

18
21

25

Social Security Disability

TOTAL
303
40

28
13

2
4
9


BIBLIOGRAPHY

Ahlman, K. 1968. Silicosis in Finland. Work, Environment, Health. 4:5-48.

Archer, V.E., J.D. Gillman, and J.K. Wagoner. 1976. Respiratory
Disease/Mortality among Uranium Miners. Ann NY Acad Sci. 271:280-293.

Axelson, 0. and L. Sundell 1978. Mining, Lung Cancer, and Smoking. Scand J
Work Environ Health 4:46-52.

Boyd, J.P., R. Doll, J.S. Faulds, and J. Leiper, 1970. Cancer of the Lung in
Iron Ore (hematite) Miners. Brit J Industry Med 27:97-105,

Cooper, W.C. 1968. Uranium Mining and Lung Cancer. JOM 10(2):82-88.

Dadisman, K.E. 1970. The Physical Demands of Coal Mining. In: Papers and
Proceedings of the National Conference on Medicine and the Federal Coal Mine
Health and Safety Act of 1969. Washington, D.C. pp. 80-81.

Decoufle, P., K. Stanislawczyk, L. Houten, I. D. J. Bross, and E. Viadana.
1977. A Retrospective Survey of Cancer in Relation to Occupation. DHEW
(NIOSH) Publication No. 77-178. NIOSH Research Report.

deVillers, A.J. and J.P. Windish. 1964, Lung Cancer in a Fluorspar Mining
Community. I. Radiation, Dust, and Mortality Experience. Brit J Industry
Med. 21:94-109,

Division of Disability Studies, Office of Research and Statistics, Social
Security Administration, 1978. Continuous Disability History Sample
Restricted Use Data File: Description and Documentation. Publication No.
024(1-78).

Edling, C. 1982. Lung Cancer and Smoking in a Group of Iron Ore Miners. Am J
Industry Med. 3(2):191-199.

Enterline, P.E. 1972. A Review of Mortality Data for American Coal Miners.
Ann NY Acad Sci 200:260-272.

Enterline, P.E. and W.S. Lainhart. 1967. The Relationship between Coal
Mining and Chronic Nonspecific Respiratory Disease. AJPH 57(3):484-495,

Executive Office of the President. 1972. Office of Management and Budget.
Standard Industrial Classification Manual.

Fairman, R.P., R.J. O'Brien, S. Swecker, H.E. Amandus, E.P. Shoub. 1977.

Respiratory Status of Surface Coal Miners in the United States. Arch Env Hlth
32(5) 2211-215.

24


not require a special examination of the claimant) according to SSA criteria;
(3) The accuracy of the determination of the cause and severity of the
disabling condition is important to the administration of the program; it is
not an issue concerning secondary uses of these data; (4) The determination of
occupation and industry of the longest held employment during the ten years
prior to disability is based on work histories obtained from the worker in
direct interviews by experienced staff; and (5) Occupational information is
obtained to satisfy administrative needs.

There are factors which reduce the usefulness or validity of these data for
epidemiologic study such as: (1) The precision and reliability of the data for
occupation and industry and disabling condition may be more related to the
administrative needs of the SSA disability system and less to occupational
health research; (2) Data on potential confounding factors, e.g. lifestyle,
use of tobacco, alcohol, and other drugs, are not available; (3) Only one
occupation and one industry is coded for each worker when, in reality, workers
may change from one occupation or industry to another and exposures in the
same occupation may vary by industry; (4) Only workers with impairments severe
enough to result in total disability are included; and (5) Not all workers
with impairments, serious injuries, or illnesses apply for benefits.

Workers may not apply for disability benefits or receive awards for a variety
of reasons which may be related to either their occupation and industry or
type of impairment. These include the following: (1) Lack of knowledge of
the benefits or confusion about requirements, e.g. a worker may erroneously
believe that the impairment must be occupationally caused; (2) The impairment
may not meet SSA requirements for severity; (3) The opportunity to apply may
be cut short by death or severe illness occurring soon after the manifestation
of the disease or the injury (although the worker's survivors may be eligible
for benefits); (4) Disease conditions with long latencies may not affect the
worker until after his retirement; and (5) Workers with conditions known to be
caused by their occupations who receive worker's compensation or other
compensation may not apply for or receive SSA disability benefit awards.

There is some evidence that tendencies to apply for benefits and appeal
initial denials are related to a worker's occupation, among other factors. It
is arguable that tendencies to apply may also be related to disease
conditions. If so the absolute incidence of disabilities by occupation and by
disabling condition, respectively, reflected by disability awards could be
deceptive. However, relationships between occupations and illness effects
might still be accurately represented by relationships between occupations and
disabling conditions of awardees. This would hold if differences among
occupational groups in tendencies to apply for benefits operate across all
types of impairments and if the characteristics of impairments related to
benefit application (if any), e.g. latency period, severity, life expectancy,
etc., operate equally across occupations. It seems reasonable that this is
the case, and there is no evidence that it is not. This is particularly
plausible for surveillance needs when the foremost objective is to detect
higher or increased risks for further investigation and knowledge of exact
magnitudes is of secondary importance.


TABLE 9 (Cont'd.)

1975-1976
ICDA PMR SE(PMR) TOTAL
Diseases of respiratory system 460-519 507 *** 28 1040
Bronchitis & asthma 490-491 ,493 —- 87
Emphysema 492 318 x** 49 244
Pneumoconiosis & related
diseases 515-516 4758 xe 512 424
Pneumoconiosis due to
silica & silicates 515 4894 xkk 530 424
Diseases of digestive system 520-577 92 26 68
Peptic ulcer 531-533 —_ 30
Cirrhosis of liver 571 63 28 23
Diseases of genitourinary system 580-629 21
Nephritis & nephrosis 580-584 16
Chronic nephritis 582 _ 16
Other diseases of urinary system 590-599 -—- 5
Diseases of skin & sub-
cutaneous tissue 680-709 — 5
Diseases of musculoskeletal
system & connective tissue 710-738 93 12 396
Rheumatoid arthritis 712 5 kkk 6 2
Osteoarthritis 713 89 18 129
Other & unspecified arthritis 710-711,
714-715 —> 12
Displacement of intervertebral
disc 725 118 26 117
Congenital anomalies 740-759 —= 13
Accidents, poisonings, & violence 800-999 77 23 98

--- The expected total number of disabled workers is less than 25 and the PMR is not
significant at the .001 level.
* The difference between PMR and 100 is statistically significant at the .05 level.
** The difference between PMR and 100 is statistically significant at the .01 level.
*** The difference between PMR and 100 is statistically significant at the .001 level.

52


10.

11.

12

13.

Estimated number and age-adjusted proportional morbidity
ratios, PMR, and standard errors, S.E.(PMR), for white

males employed in occupations in the extraction of minerals,
n.e.c. (DOT 939) in bituminous, lignite, and anthracite

coal mining (SIC 110-121) by disabling condition: Social
Security Disability Allowances, 1975-1976. .. 1... 5... ae

Estimated number and age-adjusted proportional morbidity
ratios, PMR, and standard errors, S.E.(PMR), for white

males employed in occupations in the extraction of minerals,
n.e.c. (DOT 939) in oil and gas extraction industries (SIC
130-138) by disabling condition: Social Security Disability
Allowances, 1975-1976 . 2. 1 1 2 2 ww ew ee eee we es

Estimated number and age-adjusted proportional morbidity
ratios, PMR, and standard errors, S.E.(PMR), for white

males employed in boring, drilling, cutting, and related
occupations (DOT 930) in oil and gas extraction industries
(SIC 130-138) by disabling condition: Social Security
Disability Allowances, 1975-1976 . 2... 6 2 2 ee we eee

Estimated number and age-adjusted proportional morbidity
ratios, PMR, and standard errors, S.E.(PMR), for white

males employed in extraction of minerals (DOT 930-939) in
metal mining and non-metallic minerals (SIC 100-109,

140-149) by disabling condition: Social Security Disability
Allowances, 1975-1976 . 2. 1 6 sw we we ee ete we

APPENDIX TABLES

Estimated number and age-adjusted proportional morbidity
ratios, PMR, and standard errors, S.E.(PMR), for white

males employed in the extraction of minerals (DOT 930-939)

by disabling condition other than respiratory: Social
Security Disability Awards and Allowances,

1969-1973, 1975-1976. 2 6 6 6 wee ee ee ee eee ee

Estimated number and age-adjusted proportional morbidity
ratios, PMR, and standard errors, S.E.(PMR), for white

males employed in boring, drilling, cutting, and related
occupations (DOT 930) by disabling condition other than
respiratory: Social Security Disability Awards and Allowances,
CE, EIS Go ooo DOO OOo OOD Oo ooo oO

vii

53

55

57

59

61

64


TABLE A-11: Estimated number and age-adjusted proportional morbidity ratios,
PMR, and standard errors, S.E. (PMR), for white males employed
in boring, drilling, cutting, and related occupations (DOT 930)
in oil and gas extraction industries (SIC 130-138) by disabling

condition other than respiratory:
Allowances, 1975-1976.

All disabling conditions

Neoplasms
Malignant neoplasms
Respiratory system
Neoplasms of lymphatic &
hematopoietic tissue

Endocrine, nutritional, &
metabolic diseases
Diabetes mellitus

Mental disorders
Neuroses

Diseases of nervous system &
sense organs
Multiple sclerosis

Diseases of circulatory system
Heart & hypertensive disease
Ischemic heart disease
Cerebrovascular disease
Arteriosclerosis

Diseases of digestive system
Chronic enteritis &
ulcerative colitis
Cirrhosis of liver

Diseases of musculoskeletal
system & connective tissue
Osteoarthritis
Displacement of intervertebral

disc

Congenital anomalies

140-239
140-199
160-163
200-209
240-279
250
290-315
300
320-389
340
390-458
393-429
410-414
430-438
440
520-577
563
571
710-738
713
725

740-759

84

145

100

kee
RK

1975-1976
SE(PMR)

32
29

26

58

22
27

36

Social Security Disability

42

139
111
111

10

14

143
43

83

10


TABLE 1: Diseases and ICDA-8 codes analyzed in this report.

Infective and parasitic diseases
Tuberculosis
Silicotuberculosis
Pulmonary tuberculosis
Neoplasms
Malignant neoplasms
Buccal cavity & pharynx
Digestive organs & peritoneum
Respiratory system
Bone, connective tissue, and skin
Breast
Genital organs
Urinary organs
Other & unspecified sites
Neoplasms of lymphatic & hematopoietic tissue
Sarcoma (lympho~,reticulo-), other lymphomas
Leukemia
Benign neoplasms
Neoplasms of unspecified nature
Endocrine, nutritional, & metabolic diseases
Diabetes mellitus
Diseases of blood & blood-forming organs
Mental disorders
Schizophrenia
Neuroses
Alcoholism
Diseases of nervous system & sense organs
Meningitis
Multiple sclerosis
Cataract
Glaucoma
Blindness
Diseases of circulatory system
Heart & hypertensive disease
Hypertensive disease
Ischemic heart disease
Cerebrovascular disease
Cerebral hemorrhage
Cerebral thrombosis & embolism
Arteriosclerosis
Diseases of respiratory system
Bronchitis & asthma
Emphysema
Pneumoconiosis & related diseases
Pneumoconiosis due to silica & silicates
Other pneumoconioses & related diseases
Bronchiectasis

29

000-136
010-019
010
011
140-239
140-199
140-149
150-159
160-163
170-173
174
180-187
188-189
190-199
200-209
200, 202
204-207
210-228
230-239
240-279
250
280-289
290-315
295

300

303
320-389
320

340

374

375

379
390-458
393-429
400-404
410-414
430-438
431
433-434
440
460-519
490-491, 493
492
515-516
515

518

518


Diseases of nervous system &

sense organs
Multiple sclerosis
Cataract

Glaucoma

Blindness

Diseases of circulatory

system

Heart & hypertensive
disease
Hypertensive disease
Ischemic heart disease

Cerebrovascular disease
Cerebral thrombosis &

embolism

Arteriosclerosis

Diseases of respiratory
system

TABLE 2 (Cont'd.)

ICDA

320-389
340
374
375
379

390-458
393-429
400-404
410-414
430-438
433-434
440

460-519

Bronchitis & asthma 490-491, 493

Emphysema
Pneumoconiosis & related
diseases
Pneumoconiosis due to
silica & silicates
Bronchiectasis

Diseases of digestive
system
Peptic ulcer
Chronic enteritis &
ulcerative colitis
Cirrhosis of liver

Diseases of genitourinary

system

Nephritis & nephrosis
Chronic nephritis

Other diseases of urinary
system

Diseases of male genital
organs

Diseases of skin & sub-
cutaneous tissue

492
515-516
515
518
520-577
531-533
563
571

580-629
580-584
582

590-599

600-607

680-709

SE(PMR) TOTAL

1969-1973
PMR
52 ake 6
13 *** 12
112 32
60 25
65 29
65 *** 1
70 akk 1
107 16
68 kkk 2
35 eee
46 *** 11
66 * 13
354 *RR
189 #ee 15
307 #RK 3
2280 *#* == 83
2327 ek 85
59 aK 5
101 14
58 * 15
41 ** 18
49 * 20
63 25
106 4l

32

5431
4502
235
3870
405
118
216

7716
310
4194
2180
2180
17

412
112

98
35
35
44

19

79

1975-1976
PMR SE(PMR) TOTAL
67 **R 6 (281
— 19
12
6
—- 31
73 #*k 3° 1714
75 *** 4 1408
97 «17-—s«90
76 *** 4 1241
68 «14174
77 2833
1008237
397 *** 16 2183
227, 59143
289 *** 27592
3147 *** 236 739
3240 #** 238 739
-- 17
8 = 13:16
2095558
—- 8
70 2171
1012953
148 4538
— 38
_ 15
—_— 30