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HEALTH CONSULTATION

LIBBY ASBESTOS SITE
LIBBY, LINCOLN COUNTY, MONTANA


TABLES 1 - 6

Table 1. Population Estimates
Geographic Regions of Analysis Area (in Square Miles) Population (1990 Census)
Libby City Limits
1.1
 2,532
Extended Libby Boundary
2.2
 3,694
Air Modeling
16.0
 4,300
Medical Screening
25.0
 6,072
Libby Valley
65.0
 8,617
Central Lincoln County
314.0
 9,521
Montana (Reference)
145,556.0
 799,065
U.S. (Reference)
3,597,693.0
 248,790,925


Table 2. Libby Study Population Sizes
Number of Libby Area Decedents
Libby Area Decedents Number
Initial Study Population 435
After Review of Libby Care Center Records 419
After Georeferencing 413
Decedents Falling within the Following Geographic Areas of Analysis
Central Lincoln County 400
Libby Valley 398
Medical Screening 328
Air Modeling 289
Extended Libby Boundary 278
Libby City Limits 237


Table 3. Crude Mortality Rates for Libby, Montana, 1979-1998*
 
Areas of Analysis

Underlying Causes of Mortality

State
Central Lincoln County
Libby Valley
Medical Screening
Extended Libby Boundary
Libby City Limits
Lung Cancer
[ICD-9 160-165] †
998
(8,223/823,838)
840
(80/9,521)
928
(80/8,617)
1,021
(62/6,072)
1,326
(49/3,694)
1,540
(39/2,532)
Non-Malignant Respiratory Diseases [ICD-9 460-519]
1,745
(14,373/823,838)
1,229
(117/9,521)
1,346
(116/8,617)
1,614
(98/6,072)
2,274
(84/3,694)
2,883
(73/2,532)
Digestive Cancer
[ICD-9 150-159]
912
(7,512/823,838)
546
(52/9,521)
592
(51/8,617)
708
(43/6,072)
975
(36/3,694)
1,106
(28/2,532)
Diseases of Pulmonary Circulation
[ICD-9 415-417]
102
(842/823,838)
137
(13/9,521)
151
(13/8,617)
165
(10/6,072)
244
(9/3,694)
356
(9/2,532)
Cerebrovascular Disease
[ICD-9 430-438]
1,268
(10,449/823,838)
977
(93/9,521)
1,079
(93/8,617)
1,285
(78/6,072)
1,895
(70/3,694)
2,449
(62/2,532)
Breast Cancer
[ICD-9 174]
306
(2,518/823,838)
221
(21/9,521)
244
(21/8,617)
329
(20/6,072)
487
(18/3,694)
592
(15/2,532)
Prostate Cancer
[ICD-9 185]
297
(2,444/823,838)
147
(14/9,521)
162
(14/8,617)
198
(12/6,072)
325
(12/3,694)
395
(10/2,532)

*Rates are reported per 100,000 persons and are not age-adjusted.
†ICD: International Classification of Diseases.


Table 4. Standardized Mortality Ratios by Areas of Analysis Using the Montana Population as a Reference, 1979-1998

Malignant Neoplasm of Digestive Organs and Peritoneum
[ICD-9 150-159]

Area of Analysis Observed Expected SMR* Lower 95% CI† Upper 95% CI
Libby City Limits
28
 34.4 0.8 0.5 1.2
Extended Libby Boundary
34
 41.4 0.8 0.6 1.1
Air Modeling
36
 50.0 0.7 0.5 1.0
Medical Screening
43
 61.1 0.7 0.5 0.9
Libby Valley
52
 78.7 0.7 0.5 0.9
Central Lincoln County
53
 84.1 0.6 0.5 0.8

Malignant Neoplasm of Esophagus, Stomach, Small Intestine, Colon, and Rectum
[ICD-9 150-154]

Area of Analysis Observed Expected SMR Lower 95% CI Upper 95% CI
Libby City Limits
20
 22.6 0.9 0.5 1.4
Extended Libby Boundary
24
 27.1 0.9 0.6 1.3
Air Modeling
26
 32.7 0.8 0.5 1.2
Medical Screening
29
 40.0 0.7 0.5 1.0
Libby Valley
36
 51.5 0.7 0.5 1.0
Central Lincoln County
37
 55.0 0.7 0.5 0.9

Malignant Neoplasm of Pancreas
[ICD-9 157]

Area of Analysis Observed Expected SMR Lower 95% CI Upper 95% CI
Libby City Limits
8
 7.6 1.0 0.5 2.1
Extended Libby Boundary
8
 9.2 0.9 0.4 1.7
Air Modeling
8
 11.2 0.7 0.3 1.4
Medical Screening
9
 13.7 0.7 0.3 1.2
Libby Valley
10
 17.8 0.6 0.3 1.0
Central Lincoln County
10
 19.0 0.5 0.3 1.0

Malignant Neoplasm of Respiratory and Intrathoracic Organs,
Excluding Nasal Cavities and Accessory Sinuses
[ICD-9 161-165]

Area of Analysis Observed Expected SMR Lower 95% CI Upper 95% CI
Libby City Limits
39
 35.2 1.1 0.8 1.5
Extended Libby Boundary
49
 43.4 1.1 0.8 1.5
Air Modeling
56
 53.5 1.0 0.8 1.4
Medical Screening
62
 67.1 0.9 0.7 1.2
Libby Valley
82
 88.4 0.9 0.7 1.2
Central Lincoln County
82
 95.0 0.9 0.7 1.1

Malignant Neoplasm of Trachea, Bronchus, and Lung
[ICD-9 162]

Area of Analysis Observed Expected SMR Lower 95% CI Upper 95% CI
Libby City Limits
37
 34.0 1.1 0.8 1.5
Extended Libby Boundary
47
 41.9 1.1 0.8 1.5
Air Modeling
54
 51.6 1.0 0.8 1.4
Medical Screening
60
 64.7 0.9 0.7 1.2
Libby Valley
80
 85.3 0.9 0.7 1.2
Central Lincoln County
80
 91.6 0.9 0.7 1.1

Malignant Neoplasm of Female Breast
[ICD-9 174]

Area of Analysis Observed Expected SMR Lower 95% CI Upper 95% CI
Libby City Limits
15
 10.6 1.4 0.8 2.3
Extended Libby Boundary
18
 13.3 1.4 0.8 2.1
Air Modeling
18
 16.2 1.1 0.7 1.8
Medical Screening
20
 20.5 1.0 0.6 1.5
Libby Valley
22
 27.2 0.8 0.5 1.2
Central Lincoln County
22
 29.4 0.7 0.5 1.1

Malignant Neoplasm of Prostate
[ICD-9 185]

Area of Analysis Observed Expected SMR Lower 95% CI Upper 95% CI
Libby City Limits
10
 12.3 0.8 0.4 1.5
Extended Libby Boundary
12
 14.2 0.8 0.4 1.5
Air Modeling
12
 16.9 0.7 0.4 1.2
Medical Screening
12
 19.8 0.6 0.3 1.1
Libby Valley
14
 24.4 0.6 0.3 1.0
Central Lincoln County
14
 25.8 0.5 0.3 0.9

Diseases of Pulmonary Circulation
[ICD-9 415-417]

Area of Analysis Observed Expected SMR Lower 95% CI Upper 95% CI
Libby City Limits
9
 3.9 2.3¶ 1.1 4.4
Extended Libby Boundary
9
 4.7 1.9 0.9 3.7
Air Modeling
10
 5.6 1.8 0.9 3.3
Medical Screening
11
 6.8 1.6 0.8 2.9
Libby Valley
14
 8.7 1.6 0.9 2.7
Central Lincoln County
14
 9.3 1.5 0.8 2.5

Cerebrovascular Disease
[ICD-9 430-438]

Area of Analysis Observed Expected SMR Lower 95% CI Upper 95% CI
Libby City Limits
63
 55.5 1.1 0.9 1.5
Extended Libby Boundary
71
 62.7 1.1 0.9 1.4
Air Modeling
72
 73.4 1.0 0.8 1.2
Medical Screening
79
 83.6 0.9 0.7 1.2
Libby Valley
94
 101.4 0.9 0.7 1.1
Central Lincoln County
94
 106.6 0.9 0.7 1.1

Diseases of Respiratory System,
Excluding Upper Respiratory Tract Infections
[ICD-9 480-519]

Area of Analysis Observed Expected SMR Lower 95% CI Upper 95% CI
Libby City Limits
72
 72.0 1.0 0.8 1.3
Extended Libby Boundary
84
 83.0 1.0 0.8 1.3
Air Modeling
83
 98.4 0.8 0.7 1.0
Medical Screening
98
 115.1 0.9 0.7 1.0
Libby Valley
116
 142.5 0.8 0.7 1.0
Central Lincoln County
117
 150.8 0.8 0.6 0.9

Chronic Obstructive Pulmonary Disease
[ICD-9 490-496]

Area of Analysis Observed Expected SMR Lower 95% CI Upper 95% CI
Libby City Limits
33
 37.5 0.9 0.6 1.2
Extended Libby Boundary
42
 44.3 0.9 0.7 1.3
Air Modeling
39
 53.3 0.7 0.5 1.0
Medical Screening
48
 64.0 0.7 0.6 1.0
Libby Valley
59
 80.9 0.7 0.6 0.9
Central Lincoln County
60
 86.1 0.7 0.5 0.9

Asbestosis (Represents all Pneumoconioses)
[ICD-9 501]

Area of Analysis Observed Expected SMR Lower 95% CI Upper 95% CI
Libby City Limits
5
 0.1 40.8¶ 13.2 95.3
Extended Libby Boundary
7
 0.1 47.3¶ 18.9 97.5
Air Modeling
8
 0.2 44.3¶ 19.1 87.2
Medical Screening
9
 0.2 40.6¶ 18.5 77.1
Libby Valley
11
 0.3 38.7¶ 19.3 69.2
Central Lincoln County
11
 0.3 36.3¶ 18.1 64.9

Other Diseases of the Respiratory System
[ICD-9 510-519]

Area of Analysis Observed Expected SMR Lower 95% CI Upper 95% CI
Libby City Limits
9
 4.9 1.9 0.8 3.5
Extended Libby Boundary
10
 5.7 1.7 0.8 3.2
Air Modeling
10
 6.8 1.5 0.7 2.7
Medical Screening
13
 8.1 1.6 0.8 2.7
Libby Valley
15
 10.3 1.5 0.8 2.4
Central Lincoln County
15
 10.9 1.4 0.8 2.3

*SMR: Standardized mortality ratio.
†CI: Confidence interval.
¶Statistically significant elevated SMRs.


Table 5. Standardized Mortality Ratios by Areas of Analysis Using the U. S. Population as a Reference, 1979-1998

Malignant Neoplasm of Digestive Organs and Peritoneum
[ICD-9 150-159]

Area of Analysis Observed Expected SMR* Lower 95% CI† Upper 95% CI
Libby City Limits
28
 37.5 0.7 0.5 1.1
Extended Libby Boundary
34
 45.1 0.8 0.5 1.1
Air Modeling
36
 54.6 0.7 0.5 0.9
Medical Screening
43
 66.8 0.6 0.5 0.9
Libby Valley
52
 86.1 0.6 0.5 0.8
Central Lincoln County
53
 92.0 0.6 0.4 0.8

Malignant Neoplasm of Esophagus, Stomach, Small Intestine, Colon, and Rectum
[ICD-9 150-154]

Area of Analysis Observed Expected SMR Lower 95% CI Upper 95% CI
Libby City Limits
20
 25.2 0.8 0.5 1.2
Extended Libby Boundary
24
 30.3 0.8 0.5 1.2
Air Modeling
26
 36.7 0.7 0.5 1.0
Medical Screening
29
 44.8 0.6 0.4 0.9
Libby Valley
36
 57.7 0.6 0.4 0.9
Central Lincoln County
37
 61.7 0.6 0.4 0.8

Malignant Neoplasm of Pancreas
[ICD-9 157]

Area of Analysis Observed Expected SMR Lower 95% CI Upper 95% CI
Libby City Limits
8
 7.6 1.0 0.5 2.1
Extended Libby Boundary
8
 9.2 0.9 0.4 1.7
Air Modeling
8
 11.2 0.7 0.3 1.4
Medical Screening
9
 13.8 0.7 0.3 1.2
Libby Valley
10
 17.8 0.6 0.3 1.0
Central Lincoln County
10
 19.0 0.5 0.3 1.0

Malignant Neoplasms of Respiratory and Intrathoracic Organs,
Excluding Nasal Cavities and Accessory Sinuses
[ICD-9 161-165]

Area of Analysis Observed Expected SMR Lower 95% CI Upper 95% CI
Libby City Limits
39
 39.7 1.0 0.7 1.3
Extended Libby Boundary
49
 49.2 1.0 0.7 1.3
Air Modeling
56
 60.6 0.9 0.7 1.2
Medical Screening
62
 76.3 0.8 0.6 1.0
Libby Valley
82
 100.8 0.8 0.6 1.0
Central Lincoln County
82
 108.4 0.8 0.6 0.9

Malignant Neoplasms of Trachea, Bronchus, and Lung
[ICD-9 162]

Area of Analysis Observed Expected SMR Lower 95% CI Upper 95% CI
Libby City Limits
37
 38.4 1.0 0.7 1.3
Extended Libby Boundary
47
 47.6 1.0 0.7 1.3
Air Modeling
54
 58.6 0.9 0.7 1.2
Medical Screening
60
 73.8 0.8 0.6 1.0
Libby Valley
80
 97.4 0.8 0.7 1.0
Central Lincoln County
80
 104.8 0.8 0.6 1.0

Malignant Neoplasm of Female Breast
[ICD-9 174]

Area of Analysis Observed Expected SMR Lower 95% CI Upper 95% CI
Libby City Limits
15
 11.7 1.3 0.7 2.1
Extended Libby Boundary
18
 14.6 1.2 0.7 2.0
Air Modeling
18
 17.8 1.0 0.6 1.6
Medical Screening
20
 22.5 0.9 0.5 1.4
Libby Valley
22
 29.9 0.7 0.5 1.1
Central Lincoln County
22
 32.3 0.7 0.4 1.0

Malignant Neoplasm of Prostate
[ICD-9 185]

Area of Analysis Observed Expected SMR Lower 95% CI Upper 95% CI
Libby City Limits
10
 10.3 1.0 0.5 1.8
Extended Libby Boundary
12
 11.9 1.0 0.5 1.8
Air Modeling
12
 14.2 0.8 0.4 1.5
Medical Screening
12
 16.7 0.7 0.4 1.3
Libby Valley
14
 20.7 0.7 0.4 1.1
Central Lincoln County
14
 21.9 0.6 0.3 1.1

Diseases of Pulmonary Circulation
[ICD-9 415-417]

Area of Analysis Observed Expected SMR Lower 95% CI Upper 95% CI
Libby City Limits
9
 3.7 2.4 1.1 4.6
Extended Libby Boundary
9
 4.5 2.0 0.9 3.8
Air Modeling
10
 5.4 1.8 0.9 3.4
Medical Screening
11
 6.7 1.7 0.8 3.0
Libby Valley
14
 8.6 1.6 0.9 2.7
Central Lincoln County
14
 9.2 1.5 0.8 2.6

Diseases of Respiratory System,
Excluding Upper Respiratory Tract Infections
[ICD-9 480-519]

Area of Analysis Observed Expected SMR Lower 95% CI Upper 95% CI
Libby City Limits
72
 62.2 1.2 0.9 1.5
Extended Libby Boundary
84
 72.0 1.2 0.9 1.4
Air Modeling
83
 85.2 1.0 0.8 1.2
Medical Screening
98
 99.9 1.0 0.8 1.2
Libby Valley
116
 124.0 0.9 0.8 1.1
Central Lincoln County
117
 131.2 0.9 0.7 1.1

Chronic Obstructive Pulmonary Disease
[ICD-9 490-496]

Area of Analysis Observed Expected SMR Lower 95% CI Upper 95% CI
Libby City Limits
33
 27.5 1.2 0.8 1.7
Extended Libby Boundary
42
 32.6 1.3 0.9 1.7
Air Modeling
39
 39.1 1.0 0.7 1.4
Medical Screening
48
 46.9 1.0 0.8 1.4
Libby Valley
59
 59.4 1.0 0.8 1.3
Central Lincoln County
60
 63.2 1.0 0.7 1.2

Asbestosis (Represents all Pneumoconioses)
[ICD-9 501]

Area of Analysis Observed Expected SMR Lower 95% CI Upper 95% CI
Libby City Limits
5
 0.1 63.5¶ 20.5 148.3
Extended Libby Boundary
7
 0.1 74.9¶ 30.0 154.4
Air Modeling
8
 0.1 71.0¶ 30.6 139.9
Medical Screening
9
 0.1 66.1¶ 30.2 125.5
Libby Valley
11
 0.2 63.7¶ 31.7 114.0
Central Lincoln County
11
 0.2 59.8¶ 29.8 107.0

Other Diseases of the Respiratory System
[ICD-9 510-519]

Area of Analysis Observed Expected SMR Lower 95% CI Upper 95% CI
Libby City Limits
9
 5.0 1.8 0.8 3.4
Extended Libby Boundary
10
 5.9 1.7 0.8 3.1
Air Modeling
10
 7.1 1.4 0.7 2.6
Medical Screening
13
 8.6 1.5 0.8 2.6
Libby Valley
15
 10.9 1.4 0.8 2.3
Central Lincoln County
15
 11.6 1.3 0.7 2.1

*SMR: Standardized mortality ratio.
†CI: Confidence interval.
¶Statistically significant elevated SMRs.


Table 6. Gender Specific Standardized Mortality Ratios by Areas of Analysis Using the Montana Population as a Reference, 1979-1998

Asbestosis (Represents all Pneumoconioses) -- Male
[ICD-9 501]

Area of Analysis Observed Expected SMR* Lower 95% CI Upper 95% CI
Libby City Limits
5
 0.1 52.0¶ 16.8 121.4
Extended Libby Boundary
7
 0.1 55.4¶ 22.2 114.2
Air Modeling
8
 0.2 49.3¶ 21.2 97.2
Medical Screening
8
 0.2 38.7¶ 16.6 76.2
Libby Valley
10
 0.3 36.4¶ 17.4 67.0
Central Lincoln County
10
 0.3 34.1¶ 16.3 62.7

Asbestosis (Represents all Pneumoconioses) -- Female
[ICD-9 501]

Area of Analysis Observed Expected SMR Lower 95% CI Upper 95% CI
Libby City Limits
0
 0.1 0 - -
Extended Libby Boundary
0
 0.2 0 - -
Air Modeling
0
 0.2 0 - -
Medical Screening
1
 0.2 4.6 0.1 25.7
Libby Valley
1
 0.3 3.7 0.0 20.5
Central Lincoln County
1
 0.3 3.5 0.0 19.2

*SMR: Standardized mortality ratio.
¶Statistically significant elevated SMRs.


Table 7. Gender Specific Standardized Mortality Ratios by Areas of Analysis Using the U.S. Population as a Reference, 1979-1998

Asbestosis (Represents all Pneumoconioses) -- Male
[ICD-9 501]

Area of Analysis Observed Expected SMR* Lower 95% CI Upper 95% CI
Libby City Limits
5
 0.1 76.5¶ 24.6 178.5
Extended Libby Boundary
7
 0.1 82.7¶ 33.1 170.3
Air Modeling
8
 0.1 74.7¶ 32.1 147.1
Medical Screening
8
 0.1 59.4¶ 25.6 117.0
Libby Valley
10
 0.2 56.7¶ 27.2 104.3
Central Lincoln County
10
 0.2 53.1¶ 25.4 97.7

Asbestosis (Represents all Pneumoconioses) -- Female
[ICD-9 501]

Area of Analysis Observed Expected SMR Lower 95% CI Upper 95% CI
Libby City Limits
0
 0.0 0.0 - -
Extended Libby Boundary
0
 0.0 0.0 - -
Air Modeling
0
 0.0 0.0 - -
Medical Screening
1
 0.0 161.2¶ 2.1 897.0
Libby Valley
1
 0.0 131.7¶ 1.7 732.7
Central Lincoln County
1
 0.0 124.2¶ 1.6 691.3

*SMR: Standardized mortality ratio.
¶Statistically significant elevated SMRs.


FIGURES 1 - 3

Figure 1. Aerial Photography


Figure 1a. Downtown Area


Figure 1b. Mining Area


Figure 1c. Distribution Area


Figure 1d. Exfoliation Area

Figure 2. Geographic Areas of Analysis


Figure 2a. General Vicinity


Figure 2b. Central Lincoln County


Figure 2c. Libby Valley


Figure 2d. Medical Screening


Figure 2e. Air Modeling


Figure 2f. Extended Libby Boundary


Figure 2g. Libby City Limits

Figure 3. Standardized Mortality Ratio Graphs of Asbestosis

Standardized mortality ratios (SMRs) are presented as point estimates (diamonds) along with 95% confidence intervals (bands). The geographic areas of analysis progress from the smallest region (Libby City Limits) to the largest region (Central Lincoln County).



APPENDICES 1 - 2

Appendix 1. International Classification of Diseases - 9th Revision

ICD-9 Codes Description of Underlying Cause of Death
150-159 Malignant neoplasm of digestive organs and peritoneum
   150-154 Malignant neoplasm of esophagus, stomach, small intestine, colon, and rectum
   157 Malignant neoplasm of pancreas
161-165 Malignant neoplasms of respiratory and intrathoracic organs, excluding nasal cavities and accessory sinuses
   162 Malignant neoplasms of trachea, bronchus, and lung
174 Malignant neoplasm of female breast
185 Malignant neoplasm of prostate
199 Malignancy without specification to site
415-417 Diseases of pulmonary circulation (acute cor pulmonale, pulmonary embolism and infarction, pulmonary hypertension)
430-438 Cerebrovascular disease
480-519 Nonmalignant diseases of the respiratory system, excluding upper respiratory tract infections
   490-496 Chronic obstructive pulmonary disease
   500-505 Pneumoconioses
   501 Asbestosis
   510-519 Other disease of respiratory system (emphysema, pleurisy, pneumothorax, pulmonary congestion, pulmonary collapse, respiratory failure)


Appendix 2. Montana Death Certificate

Table of Contents








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