Workshop: Public Health Significance of Smoking-Asbestos Interactions
PUBLIC HEALTH SIGNIFICANCE OF SMOKINGASBESTOS INTERACTIONS Arthur L. Frank Environmental Sciences Laboratory Department of Community Medicine Mount Sinai School of Medicine The City University of New York New York.New York 10029
Dr. Frank opened the session by briefly reviewing the, status of knowledge regarding smoking-asbestos interactions. The seminal paper on this subject was cited, that of Selikoff, et al.’ Dr. Meurman spoke of the experience in Finland. He stated that from studies i n Finland, it appeared that asbestos exposure in general is minimal, but every adult person has small amounts of asbestos in their lungs. He stated that there might be differences in the health effects of various types of asbestos but in Finland there appeared to be no rise in the risk of lung cancer. The asbestos levels near the Finnish anthophyllite mines seemed to cause pleural changes but not to raise the risk of lung cancer among the general population. The risk of employees appear to be 1.4: 1 if they had been exposed to low to moderate asbestos dust levels. (Ed. note: no numbers were cited.) For heavily exposed miners and millers with two years or longer exposure, the risk of lung cancer appears to be 3.3:l. suggesting a dose-response relationship with anthophyllite. All cases of lung cancer were in males, and of the 44 cases, all but one occurred in smokers. He suggested that a nonsmoking asbestos worker had a risk of I .6, a non asbestos exposed smoker 12, and a smoking asbestos worker 19. Dr. Frank reviewed other multiple factor interactions and reviewed the biological and medical problems caused by all forms of asbestos. Mr. Seidman presented some unpublished results on death rates in relation to asbestos work and cigarette smoking exposures from the study by Hammond, Selikoff and Seidman.* I n that study, age standardized death rates for asbestos insulation workers subsequent to 20 years from first asbestos employment were compared for the period 1967-1976 with rates based on a control group of men who were analogous in various respects aside from the asbestos work exposure. The control group was composed of men from the American Cancer Society prospective epidemiological study who met the following specifications: white, not a farmer, no more than high school education, a history of occupational exposure to dust, fumes, vapors, gases, chemicals or radiation, and alive as of January 1, I967 and traced therafter. TABLES 1 and 2 show data for four groups of men: Group I. No asbestos work and no smoking-the control group men who never smoked regularly. Group I I . No asbestos work but cigarettes-the control group men who were either current or ex-cigarette smokers. Group 111. Asbestos work and no smoking-the asbestos insulation workers who had never smoked regularly. Group IV. Asbestos work and cigarette sn,oking-the asbestos insulation workers who were either current or ex-cigarette smokers.
79 1 0077-8923/79/033&079I 501.75 0 1979. NYAS
Annals New York Academy of Sciences
792
TABLE1 AGE STANDARDIZED DEATHRATESFOR CIGARETTE SMOKING AND/OR OCCUPATIONAL EXPOSURE TO ASBESTOSDUST COMPARED WITH NO SMOKING AND NO OCCUPATIONAL EXPOSURE TO ASBESTOSDUST FOR SELECTED CAUSES OF DEATH*
Group
Noninfectious Pulmonary Diseases All All All (Total includes Other Causes Cancer Asbestosis) Asbestosis Causes
A. Death Rates Per 100.000 Man-Years 1. No asbestos work and no smoking 980.9 208.2 11. No asbestos work and cigarettes 1580.7 353.1 Ill. Asbestos work and no smoking 1430.9 563.9 2659.0 1317.0 IV. Asbestos work and cigarettes
28.8
**
743.9
103.8
**
1123.8
77.1
77.1 225.5
789.9 1005.5
286.5
B. Mortality Ratios No asbestos work and no smoking (I + I) No asbestos work and cigarettes (11 i I) Asbestos work and no smoking (Ill t I) Asbetos work and cigarettes (IV + I) C. Excess in Death Rates V. “Cigarettes only” (I1 - I) VI. “Asbestos work only” (111 - I) VII. “Synergism” (IV - I - v - VI) D. Percent Excess in Death Rates “Cigarettes only” (IOOV iI) “Asbestos work only” (IooVI i I) “Synergism” rioovri + I)
1.oo
I .oo
1.oo
-
1 .oo
1.61
I .70
3.60
-
1.51
1.46
2.71
2.68
-
1.06
2.71
6.33
9.95
-
1.42
599.8
144.9
75.0
**
379.9
450.0
355.7
48.3
77.1
46.0
628.3
608.2
134.4
148.4
- 114.3
61
70
260
-
51
46
171
168
-
6
64
292
467
-
- 15
*Rate per 100,OOO man-years standardized for age on the distribution of the man-years of all the asbestos insulation workers 20+ years after onset of asbestos work. Rates for the asbestos work exposure groups are based on cause of death coded according to best evidence available (BE). **Death rates not available for the no asbestos work exposure groups, but these have been rare causes of death in the general population.
In order to show more difinitive figures for asbestosis and mesothelioma, the death 1 and 2 were based on cause of rates for the asbestos insulation workers in TABLES death coded according to best evidence available (BE), rather than on death certificate information only (DC). See Hammond, Selikoff and Seidman.* TABLE1 is concerned with all causes of death, all cancer, all noninfectious pulmonary diseases (including asbestosis), separate figures for asbestosis, and all 2 shows the findings for several types of cancer. other causes. TABLE Four sections a r e shown for each of the relevant causes of death. Section A
793
Frank: Asbestos Exposure and Smoking
presents the age-standardized death rates per 100,000 man-years for each of the four groups. For example, for total cancer the death rate was 208 per 100,000 man-years in the absence of both asbestos work exposure and smoking. It was 353 with cigarette smoking only, 564 with asbestos work exposure only, and 13 17 with both exposures. Section B shows the death rates in the various groups as a ratio of the rates in Group I. Thus for total cancer the ratio was 1 .OO in the absence of both asbestos work exposure and smoking (by definition). It was 1.70 times as high for cigarette smoking only, 2.71 times as high for asbestos work exposure only and 6.33 times as high with both asbestos work exposure and cigarette smoking. TABLE2 AGE STANDARDIZED DEATHRATESFOR ClGARElTE S M O K I N G AND/OR OCCUPATIONAL EXPOSURE TO ASBESTOSDUST COMPARED WITH NO SMOKING AND NO OCCUPATIONAL EXPOSURE TO ASBESTOSDUSTFOR SELECTED CAUSES OF DEATH*
Group
Lung MesoCancer thelioma
A. Death Rates Per 100,000 Man-Years I. No asbestos work and no smoking 11.3 I I . No asbestos work and 122.6 cigarettes 111. Asbestos work and no 80.2 smoking IV. Asbestos work and cigarettes 693.8
Cancer of Esophagus, Larynx, Buccal, Pharynx
ColonRectum Cancer
All Other Cancers
**
2.5
38.4
156.0
**
18.1
39.7
172.7
230.4 236.6
0.0 57.2
57.9 75.1
195.4 253.7
B. Mortality Ratios to No Asbestos and No Smoking No asdestos work and no smoking (I t I) No asbestos work and cigarettes (I1 i I) Asbestos work and no smoking (111 i I) Asbetos work and cigarettes (IV t I ) C. Excess in Death Rates V. “Cigarettes only” (I1 - I) VI. “Asbestos work only” (111 - I) VII. “Synergism” (IV - I - v - VI) D. Percent Excess in Death Rates “Cigarettes only” (IOOV i I) “Asbestos work only” (IOOVI t I ) “Synergism” (ioOvii t I)
1.oo
I .oo
1 .oo
1.oo
10.85
7.24
I .03
1.1 I
7.10
0.00
1.51
I .25
61.40
22.88
1.97
1.63
15.6
1.3
16.7
19.5
39.4
16.5
41.6
624
3
11
100
51
25
1664
43
27
111.3
-2.5
68.9
41.6
502.3 985 610 4445
-
~
*Rate per 100,000 man-years standardized for age on the distribution of the man-years of all asbestos insulation workers 20+ years after onset of asbestos work. Rates for the asbestos work exposure groups are based on cause of death coded according to best evidence available (BE). **Death rates not available for the no asbestos work exposure groups, but these have been rare causes of death in the general population.
794
Annals New
York Academy of Sciences
In Section C the death rates in the absence of both exposures have been. regarded as “baseline” figures. Subtracting the “baseline” rates from the cigarette smoking only rates and from the asbestos work exposure only rates yields the excesses in rates assignable to “cigarettes only” and to “asbestos work only.” For total cancer the “baseline” rate was 208 per 100,000 man-years, the “cigarette only” excess was 353 - 208 145, and the “asbestos work exposure only” excess was 564 - 208 356. Assuming that cigarette smoking and asbestos work exposure acted independently with respect to cancer death rates we would expect the cancer rates for men with both asbestos work exposure and cigarette smoking to be approximately the sum of 208 +
-
185
-
+ 356 = 709.
-
The observed figures was 1317. The difference, 1317 - 709 608, was presumably the synergistic effect of the combined exposure. Section D gives the excess in rates calculated in Section C as a percent of the “baseline” rates. For total cancer, “cigarettes only” added 70% more deaths, “asbestos work only” added 171% more deaths and the “synergistic” excess was almost 300%. Obviously, other factors are involved and the synergism figures derived should not be taken literally, but rather as approximations. Nevertheless it is amply clear that cigarette smoking poses special hazards to asbestos workers. Conversely, avoiding cigarette smoking offers them special benefits.
REFERENCES 1 . SELIKOFF, 1. J., E. C. HAMMOND & J. CHURC.1968. Asbestos exposure, smoking and neoplasia. JAMA. 204: 106-1 12. 2. HAMMOND. E. C.. 1. J . SELIKOFF & H. SEIDMAN, 1979. Asbestos exposure, cigarette smoking and death rates. Ann. N.Y.Acad. Sci. This volume.
PUBLIC HEALTH SIGNIFICANCE OF SMOKINGASBESTOS INTERACTIONS Arthur L. Frank Environmental Sciences Laboratory Department of Community Medicine Mount Sinai School of Medicine The City University of New York New York.New York 10029
Dr. Frank opened the session by briefly reviewing the, status of knowledge regarding smoking-asbestos interactions. The seminal paper on this subject was cited, that of Selikoff, et al.’ Dr. Meurman spoke of the experience in Finland. He stated that from studies i n Finland, it appeared that asbestos exposure in general is minimal, but every adult person has small amounts of asbestos in their lungs. He stated that there might be differences in the health effects of various types of asbestos but in Finland there appeared to be no rise in the risk of lung cancer. The asbestos levels near the Finnish anthophyllite mines seemed to cause pleural changes but not to raise the risk of lung cancer among the general population. The risk of employees appear to be 1.4: 1 if they had been exposed to low to moderate asbestos dust levels. (Ed. note: no numbers were cited.) For heavily exposed miners and millers with two years or longer exposure, the risk of lung cancer appears to be 3.3:l. suggesting a dose-response relationship with anthophyllite. All cases of lung cancer were in males, and of the 44 cases, all but one occurred in smokers. He suggested that a nonsmoking asbestos worker had a risk of I .6, a non asbestos exposed smoker 12, and a smoking asbestos worker 19. Dr. Frank reviewed other multiple factor interactions and reviewed the biological and medical problems caused by all forms of asbestos. Mr. Seidman presented some unpublished results on death rates in relation to asbestos work and cigarette smoking exposures from the study by Hammond, Selikoff and Seidman.* I n that study, age standardized death rates for asbestos insulation workers subsequent to 20 years from first asbestos employment were compared for the period 1967-1976 with rates based on a control group of men who were analogous in various respects aside from the asbestos work exposure. The control group was composed of men from the American Cancer Society prospective epidemiological study who met the following specifications: white, not a farmer, no more than high school education, a history of occupational exposure to dust, fumes, vapors, gases, chemicals or radiation, and alive as of January 1, I967 and traced therafter. TABLES 1 and 2 show data for four groups of men: Group I. No asbestos work and no smoking-the control group men who never smoked regularly. Group I I . No asbestos work but cigarettes-the control group men who were either current or ex-cigarette smokers. Group 111. Asbestos work and no smoking-the asbestos insulation workers who had never smoked regularly. Group IV. Asbestos work and cigarette sn,oking-the asbestos insulation workers who were either current or ex-cigarette smokers.
79 1 0077-8923/79/033&079I 501.75 0 1979. NYAS
Annals New York Academy of Sciences
792
TABLE1 AGE STANDARDIZED DEATHRATESFOR CIGARETTE SMOKING AND/OR OCCUPATIONAL EXPOSURE TO ASBESTOSDUST COMPARED WITH NO SMOKING AND NO OCCUPATIONAL EXPOSURE TO ASBESTOSDUST FOR SELECTED CAUSES OF DEATH*
Group
Noninfectious Pulmonary Diseases All All All (Total includes Other Causes Cancer Asbestosis) Asbestosis Causes
A. Death Rates Per 100.000 Man-Years 1. No asbestos work and no smoking 980.9 208.2 11. No asbestos work and cigarettes 1580.7 353.1 Ill. Asbestos work and no smoking 1430.9 563.9 2659.0 1317.0 IV. Asbestos work and cigarettes
28.8
**
743.9
103.8
**
1123.8
77.1
77.1 225.5
789.9 1005.5
286.5
B. Mortality Ratios No asbestos work and no smoking (I + I) No asbestos work and cigarettes (11 i I) Asbestos work and no smoking (Ill t I) Asbetos work and cigarettes (IV + I) C. Excess in Death Rates V. “Cigarettes only” (I1 - I) VI. “Asbestos work only” (111 - I) VII. “Synergism” (IV - I - v - VI) D. Percent Excess in Death Rates “Cigarettes only” (IOOV iI) “Asbestos work only” (IooVI i I) “Synergism” rioovri + I)
1.oo
I .oo
1.oo
-
1 .oo
1.61
I .70
3.60
-
1.51
1.46
2.71
2.68
-
1.06
2.71
6.33
9.95
-
1.42
599.8
144.9
75.0
**
379.9
450.0
355.7
48.3
77.1
46.0
628.3
608.2
134.4
148.4
- 114.3
61
70
260
-
51
46
171
168
-
6
64
292
467
-
- 15
*Rate per 100,OOO man-years standardized for age on the distribution of the man-years of all the asbestos insulation workers 20+ years after onset of asbestos work. Rates for the asbestos work exposure groups are based on cause of death coded according to best evidence available (BE). **Death rates not available for the no asbestos work exposure groups, but these have been rare causes of death in the general population.
In order to show more difinitive figures for asbestosis and mesothelioma, the death 1 and 2 were based on cause of rates for the asbestos insulation workers in TABLES death coded according to best evidence available (BE), rather than on death certificate information only (DC). See Hammond, Selikoff and Seidman.* TABLE1 is concerned with all causes of death, all cancer, all noninfectious pulmonary diseases (including asbestosis), separate figures for asbestosis, and all 2 shows the findings for several types of cancer. other causes. TABLE Four sections a r e shown for each of the relevant causes of death. Section A
793
Frank: Asbestos Exposure and Smoking
presents the age-standardized death rates per 100,000 man-years for each of the four groups. For example, for total cancer the death rate was 208 per 100,000 man-years in the absence of both asbestos work exposure and smoking. It was 353 with cigarette smoking only, 564 with asbestos work exposure only, and 13 17 with both exposures. Section B shows the death rates in the various groups as a ratio of the rates in Group I. Thus for total cancer the ratio was 1 .OO in the absence of both asbestos work exposure and smoking (by definition). It was 1.70 times as high for cigarette smoking only, 2.71 times as high for asbestos work exposure only and 6.33 times as high with both asbestos work exposure and cigarette smoking. TABLE2 AGE STANDARDIZED DEATHRATESFOR ClGARElTE S M O K I N G AND/OR OCCUPATIONAL EXPOSURE TO ASBESTOSDUST COMPARED WITH NO SMOKING AND NO OCCUPATIONAL EXPOSURE TO ASBESTOSDUSTFOR SELECTED CAUSES OF DEATH*
Group
Lung MesoCancer thelioma
A. Death Rates Per 100,000 Man-Years I. No asbestos work and no smoking 11.3 I I . No asbestos work and 122.6 cigarettes 111. Asbestos work and no 80.2 smoking IV. Asbestos work and cigarettes 693.8
Cancer of Esophagus, Larynx, Buccal, Pharynx
ColonRectum Cancer
All Other Cancers
**
2.5
38.4
156.0
**
18.1
39.7
172.7
230.4 236.6
0.0 57.2
57.9 75.1
195.4 253.7
B. Mortality Ratios to No Asbestos and No Smoking No asdestos work and no smoking (I t I) No asbestos work and cigarettes (I1 i I) Asbestos work and no smoking (111 i I) Asbetos work and cigarettes (IV t I ) C. Excess in Death Rates V. “Cigarettes only” (I1 - I) VI. “Asbestos work only” (111 - I) VII. “Synergism” (IV - I - v - VI) D. Percent Excess in Death Rates “Cigarettes only” (IOOV i I) “Asbestos work only” (IOOVI t I ) “Synergism” (ioOvii t I)
1.oo
I .oo
1 .oo
1.oo
10.85
7.24
I .03
1.1 I
7.10
0.00
1.51
I .25
61.40
22.88
1.97
1.63
15.6
1.3
16.7
19.5
39.4
16.5
41.6
624
3
11
100
51
25
1664
43
27
111.3
-2.5
68.9
41.6
502.3 985 610 4445
-
~
*Rate per 100,000 man-years standardized for age on the distribution of the man-years of all asbestos insulation workers 20+ years after onset of asbestos work. Rates for the asbestos work exposure groups are based on cause of death coded according to best evidence available (BE). **Death rates not available for the no asbestos work exposure groups, but these have been rare causes of death in the general population.
794
Annals New
York Academy of Sciences
In Section C the death rates in the absence of both exposures have been. regarded as “baseline” figures. Subtracting the “baseline” rates from the cigarette smoking only rates and from the asbestos work exposure only rates yields the excesses in rates assignable to “cigarettes only” and to “asbestos work only.” For total cancer the “baseline” rate was 208 per 100,000 man-years, the “cigarette only” excess was 353 - 208 145, and the “asbestos work exposure only” excess was 564 - 208 356. Assuming that cigarette smoking and asbestos work exposure acted independently with respect to cancer death rates we would expect the cancer rates for men with both asbestos work exposure and cigarette smoking to be approximately the sum of 208 +
-
185
-
+ 356 = 709.
-
The observed figures was 1317. The difference, 1317 - 709 608, was presumably the synergistic effect of the combined exposure. Section D gives the excess in rates calculated in Section C as a percent of the “baseline” rates. For total cancer, “cigarettes only” added 70% more deaths, “asbestos work only” added 171% more deaths and the “synergistic” excess was almost 300%. Obviously, other factors are involved and the synergism figures derived should not be taken literally, but rather as approximations. Nevertheless it is amply clear that cigarette smoking poses special hazards to asbestos workers. Conversely, avoiding cigarette smoking offers them special benefits.
REFERENCES 1 . SELIKOFF, 1. J., E. C. HAMMOND & J. CHURC.1968. Asbestos exposure, smoking and neoplasia. JAMA. 204: 106-1 12. 2. HAMMOND. E. C.. 1. J . SELIKOFF & H. SEIDMAN, 1979. Asbestos exposure, cigarette smoking and death rates. Ann. N.Y.Acad. Sci. This volume.
