Addendum to IDSP Report No.12 Report to the Workers' Compensation Board on Lung Cancer in the Hardrock Mining Industry

September, 1996
ODP Report No. 12A
Occupational Disease Panel (Industrial Disease Standards Panel)
Toronto


Relevant Links

Gold Mining
Healthy Worker Effect
Uranium Mining
Scleroderma
Hardrock Mining Industry
Nickel Industry:Cancer of Larnyx

Occupational Disease Panel

In 1985, the Ontario legislature established the Industrial Disease Standards Panel to investigate and identify diseases related to work. The Panel is independent of both the Ministry of Labour and the Workers' Compensation Board. At the end of each fiscal year the WCB reimburses the Ministry for the Panel's expenditures. In 1995, the name was changed to the Occupational Disease Panel (ODP).

The Panel's authority flows from section 95 of the Workers' Compensation Act and its functions are set out as follows:

95(8)

(a) to investigate possible industrial diseases;

(b) to make findings as to whether a probable connection exists between a disease and an industrial process, trade or occupation in Ontario;

(c) to create, develop and revise criteria for the evaluation of claims respecting industrial diseases; and

(d) to advise on eligibility rules regarding compensation for claims.

Decisions of the Panel are made by its members who represent labour, management, scientific, medical and community interests. Once the Panel makes a finding, the WCB is required to publish the Panel's report in the Ontario Gazette and solicit comments from interested parties. After considering the submissions the WCB Board of

Directors decide if the Panel's recommendations are to be implemented, amended or rejected.

To assist with its work, the Panel has a small staff of researchers, analysts and support people. In addition to its own staff, the Panel relies heavily on the advice of outside experts in science, medicine and law, as well as input from parties of interest.

Additional copies of this publication are available by writing:

Occupational Disease Panel
69 Yonge Street, Suite 1004
Toronto, Ontario M5E 1K3
(416) 327-4156


Panel Membership

Panel Members
Appointment
Ms. Nicolette Carlan (Chair)   May 16, 1991 to May 15, 1997
Mr. James Brophy January 23, 1992 to January 22, 1998
Dr. Carol Buck June 1, 1991 to June 16, 1997
Mr. William Elliott November 7, 1991 to November 6, 1997
Mr. John Macnamara November 7, 1991 to November 6, 1997
Mr. Homer Seguin May 28, 1992 to May 27, 1998
Dr. Michael Wills November 7, 1991 to November 6, 1997

Panel Staff

Panel Staff  
Carolyn Archer Senior Research Officer
Robert Chase Medical Consultant
Francis Macri Policy Analyst
Cara Melbye Policy Analyst
Anne Rekenye Data Entry Clerk
Tracy Soyka Project Co-Ordinator
Barry Spinner Policy Analyst
Salima Storey Administrative Officer
George Tomlinson Biostatistician
Jason Tung Occupational Hygienist

TABLE OF CONTENTS

Letter of transmittal

Section One

Introduction
Background
Refinement of Cohort

Section Two

Results
Overall
Sintering Plant
Underground Production Mining(UGPM)
Milling
Smelting
Refining
Iron Ore Recovery Plant(IORP)
Transportation and Maintenance Personnel

Section Three

Discussion

Section Four

Conclusion

References

Appendix A

Glossary and Tables

Tables

Table 5. Adjusted SIR's
Lung Cancer incidence - Underground Mining

Table 12. Cause-specific SMR
Combined cohort (never sinter)

Table 13. Cause-specific SMR
Combined cohort (any sinter)

Table 14. Cause-specific SMR
Combined cohort UGPM (never sinter)

Table 15. Cause-specific SMR
Combined Sudbury Cohort (never UGPM) (never sinter)

Table 21. Lung Cancer
Sudbury Cohort (never sinter)

Table 22. Lung Cancer
INCO Port Colborne (never sinter)

Table 23. Lung Cancer
INCO Sintering - Copper Cliff & Port Colborne

Table 24. Lung Cancer
Copper Cliff Sinter Plant

Table 25 Lung Cancer
Other Sintering - Falconbridge & Coniston Sinter Plants

Table 26 Lung Cancer
INCO-Falconbridge combined UGPM (never sinter)

Table 27. Lung Cancer
INCO-Falconbridge UGPM (never sinter)

Table 28. Lung Cancer SIRs & CMFs
INCO UGPM, hourly & foreman (never sinter) by decade of 1st exposure

Table 30. Lung Cancer SIRs & CMFs
Falconbridge UGPM (never sinter) by decade of 1st exposure

Table 32. Lung Cancer Risk Estimates
INCO-Falconbridge combined milling (never sinter)

Table 33. Lung Cancer Risk Estimates
INCO-Falconbridge Milling (never sinter)

Table 34. Lung Cancer Risk Estimates
INCO-Falconbridge combined smelting (never sinter)

Table 35. Lung Cancer Risk Estimates
INCO Copper Cliff & Coniston Smelters (never sinter)

Table 36. Lung Cancer Risk Estimates
Falconbridge smelter

Table 37. Lung Cancer Risk Estimates
INCO Copper Cliff Refinery and Tankhouse (never sinter)

Table 38. Lung Cancer Risk Estimates
INCO Iron Ore Recovery Plant (never sinter)

Table 39. Lung Cancer Risk Estimates
INCO Transportation & Maintenance Personnel (never sinter)


SECTION ONE

Introduction

In 1990, the Industrial Disease Standards Panel (now the Occupational Disease Panel (ODP)), contracted with a research team at McMaster University to undertake a comprehensive morbidity study of laryngeal and other cancers among nickel workers in Ontario. A summary of the findings of this study as they pertain to lung cancer among nickel workers is presented in the following pages and should be regarded as supplemental to pages 26-29 of the Occupational Disease Panel's report No.12, "Report to the Workers' Compensation Board on Lung Cancer in the Hardrock Mining Industry ", March 1994 (3).

Background

In a letter dated September 15, 1988, Dr. Robert G. Elgie, Chairman of the Workers' Compensation Board, asked the Panel "to review the Board's current guidelines on the adjudication of claims for laryngeal cancer in the nickel industry " (2). In particular, the Board requested advice with respect to the following questions:

1) Is there a causal relationship between occupational exposure to nickel and the development of laryngeal cancer?

2) If yes, what should be the criteria and eligibility rules for evaluation of claims respecting laryngeal cancer among nickel-exposed workers?

Of particular concern at the time of the referral was that the majority of studies reviewed to date had focused on mortality data as an endpoint, rather than incidence data. Since laryngeal cancer has a high survival rate, substantial numbers of workers with laryngeal cancer could have been missed if only deaths were counted. Hence suspicions regarding increased risks from laryngeal cancer among nickel workers could neither be proved nor disproved.

Accordingly, the Panel contracted with Dr. David Muir and colleagues at McMaster University to conduct a study of the incidence of cancer of the larynx among Ontario nickel workers at INCO and Falconbridge. Because previous studies had also shown pockets of other cancers among various occupational subgroups within the nickel industry, the ODP requested that other cancers, especially respiratory, be included. Dr. Muir is Head of the Occupational Health Program, the unit which conducted the previous mortality studies on Ontario nickel workers.

A revised protocol was accepted by the Panel in February, 1990 and an addendum adding the Falconbridge cohort was approved in September, 1990. This exhaustive combined cohort study was therefore underway during the time of the Panel deliberations that resulted in Report No. 12 on the hardrock mining industry. Report No.12 contains a summary of findings of the earlier mortality studies conducted by various McMaster teams as they pertained to lung cancer.

A draft report of the incidence study was received in April, 1995 and sent out to three peer reviewers as is the practice of the Panel. These reviews were shared with the McMaster team. The final report, "A Study of Cancer Incidence in Ontario Nickel Workers" was received by the Panel on January 15, 1996 (5).

Refinement of the Cohort

The process for defining the cohort from two large nickel operations was exceedingly complex. The original INCO cohort assembled by Roberts and colleagues consisted of approximately 54,500 men while Shannon et al.'s Falconbridge cohort comprised about 11,600. In addition, more than 2500 men worked for both companies. Difficulties in reconciling job titles between the two corporations were also encountered because the activities were not identical. The process at Falconbridge did not include the final refining process. Because of earlier and strong evidence linking Ontario sintering operations with sino-nasal and lung cancer, workers with any sintering plant experience were removed from the main cohort to form one of many sub-cohorts.

Because few reliable exposure estimates were available, INCO cohort members were classified into sub-groups by process and/or location based on their hierarchical job codes. These classifications were originally designed for payroll and accounting purposes. Falconbridge, on the other hand, assigned workers as exposed or unexposed based on hygiene assessments of areas defined by department codes.

Following a preliminary presentation of the study results at a meeting in September, 1994, Panel members expressed concern that the development of the INCO cohort using job classifications intended for payroll and accounting needs had diluted the actual workplace cohorts by including large numbers of unexposed and out-of-Province nickel workers. Accordingly, the Panel requested that the research team:

The Panel also requested various sub-group analyses for both cohorts, a detailed description of which can be found in the McMaster report on page 19.

Seven linkages involving three agencies were further supplemented by additional diligent efforts on the part of the McMaster team to resolve conflicts and questionable links. This cohort should now reflect the best ascertainment to date with the longest period of follow-up of nickel workers in Ontario. It is hoped that these herculean efforts have resulted in what is now the most accurate analysis to date of cancer, and in particular, lung cancer, in this large working population.

The data on lung cancer among nickel workers from this study therefore forms the basis of this Addendum to the Hardrock Mining Report and should be viewed as supplemental to pages 26-29 of Panel Report No.12.


SECTION TWO

Results

For reasons outlined in the full report, the McMaster team used several outcome measures. For simplicity's sake and as the study was originally commissioned to analyze cancer incidence, the results in this Addendum are described for the Standard Incidence Ratio (SIR) only(1). Charts from the Muir/Julian study referred to in this text are included as Appendix A.

Overall

Tables 21 through 39 in the McMaster Study depict the incidence of lung cancer among the various cohorts and sub-cohorts. Data for the large Sudbury area cohorts of INCO and Falconbridge workers, never sinter exposed, are shown in Table 21. INCO workers show a statistically significant excess risk for lung cancer (SIR=134) with 35+ years duration of exposure(DOE)(2). The INCO Port Colborne cohort, never sinter, shows no excess risk (Table 22).

Sintering Plant

Copper Cliff and Port Colborne L,C&S(3)

As shown in previous studies (6,7,1), an increase in lung cancer risk is apparent, even among workers exposed for short durations, at the Copper Cliff sintering plant and less marked in the Port Colborne L,C&S plant(Table 23). A statistically significant SIR was reached with less than three months of exposure in the Copper Cliff operation (SIR=193) and with three to six months of exposure (SIR=228) at the Port Colborne facility.

[Extracted from Table 23]
                 Copper Cliff     Port Colborne
                 ------------     -------------
DOE                       SIR               SIR
<1mo                       47               133
1<3mo                     193*               83
3<6mo                      90               228*
6<12mo                    209*              186
01<02yr                   228*              126
02-04yr                   308*              138
05-09yr                   457*              298*
>10yr                     729*            283.5*

* = statistically significant

The increased incidence at Copper Cliff appeared within 10 years or more since first exposure (YSFE) but not until 15 YSFE at Port Colborne. The lifespan of the Copper Cliff sintering plant was short (1948-1963). Table 24 reflects the investigators' attempt to evaluate reports that process changes made in late 1951 greatly reduced the risks for lung (and nasal) cancer. Most of the lung cancer cases occurred in the group first exposed before 1952, leaving few cases in the exposure cells in 1952 or later. Even so, each of the several summary methods is elevated beyond one year and reaches statistical significance after 5 years.

Coniston and Falconbridge

Table 25 shows a statistically significant elevation overall for the Falconbridge sinter plant cohort (SIR=141). However, there is not a completely regular increase in risk with duration of exposure. The Coniston operation shows an increasing trend with duration but is limited by small numbers of cases.(4)

[Extracted from Table 25]
            Falconbridge       INCO Coniston
            ------------       -------------
DOE             SIR                 SIR
<3mo            149	
3<6mo           169
6<12mo          104                  79
01<02yr         124
02-04yr         180                 179  
05-09yr          93                 461
10+yr           194                 162
All             141*                173

* = statistically significant

Underground Production Mining (UGPM)

Table 26 shows the risk estimates for lung cancer in the combined INCO-Falconbridge cohort (28,270 and 6,046 men respectively) by duration of exposure. The SIR at 25-29 years of exposure is a statistically significant 142. Tests for trend were significant beyond 20 years for the combined cohort. Table 27 shows that the SIR for INCO reaches statistical significance in the 25-29 year cell (SIR=132) and rises to 178 in the 35+ cell(Table 27). Falconbridge SIRs do not reach statistical significance in the SIR outcome measure, possibly due to the smaller number of observed and expected deaths, the authors postulate. However, the combined INCO-Falconbridge underground mining cohort is a statistically significant 171, in the 35+ cell.

[Extracted from Tables 26 & 27]
            INCO    Falconbridge        Combined
            ----    ------------        --------
DOE          SIR             SIR             SIR
00<01         66              59              62
01<02         82              94              79
02-04         86              57              77
05-09         95             106              97
10-14         81             100              86
15-19        108             148             118
20-24        111             135             106
25-29        132*            158             142*
30-34        133*            184             139*
35+          178*            135             171*				 			

* = statistically significant

The authors also examined possible effects of changes in mining methods and hence possibly exposures over time by forming sub-cohorts by decade of first exposure to nickel mining (Table 28).

For the INCO UGPM cohort, the SIRs of those who first mined before 1930 are almost all statistically significant, regardless of duration of exposure. Dose-response trends are inconsistent for 1930-1939 and 1940-49, while INCO miners first exposed in the 50's show a trend for increasing risk with exposure after 15 years or more. Those most recently exposed in 1960 or later show an unexpectedly large excess (SIR of 195, but not statistically significant) for durations of one to two years.

An analysis by number of years worked for each of the decades of first nickel exposure revealed that for the pre-1930 workers there was a flat relative risk, but for the other decades, there was an increasing trend after 20 years employment and statistically significant risk in the 35+ cell, with SIRs ranging from 122 to 147). The curious cluster of 9 cancer cases in the one to two year bin first nickel exposed after 1960, now appears in the 15 to 20 years duration of work level (SIR=167). In other words, these cases had worked in other departments for INCO for at least 14 years.

The Falconbridge data show similar patterns but are more difficult to assess for trend because of the relatively small number of cases spread over many cells (Table 30). In the miners first exposed between 1940 and 1949, a linear trend is apparent from fifteen years on and statistically significant doubling of the risk occurs with 25 or more years of exposure.(5) The risk estimates for 1950-59 show no statistically significant excesses, while for those first exposed in 1960 or later, 11 of the 13 cases observed occur in those exposed for 10 years or more (SIR 259) overall.

Milling

Relative risk estimates for lung cancer in the combined milling cohort and in the company-specific cohorts show no trends of increasing risk with increasing duration of exposure (Tables 32-33). However, the INCO millers showed a scattered pattern of elevated SIRs and for those with between one and five years exposure, the SIR was a statistically significant 153.

Smelting

The combined cohort showed no indication of an increased risk with any duration examined (Table 34). The company-specific results, broken down into INCO's Copper Cliff and Coniston smelter operations, and Falconbridge's smelter, did not show any increased incidence of lung cancer. The latter analysis was based on a very small number of exposed workers as a result of the removal of the sinter plant workers and many men who had worked as smelter labourers (Table 35). When these sinter plant workers were added back to the "pure" smelter worker cohort, two and three-fold elevated risks, though not statistically significant, were seen in workers with two to 10 years smelter experience [p.79] (Table 36).

Refining

INCO's Copper Cliff refinery workers show elevated risks especially with exposures of greater than 25 years, although not statistically significant. Workers with greater than 30 years exposure in the tankhouse department exhibit a risk two to three times normal, although again, not statistically significant (Table 37). Falconbridge ships their nickel matte to Norway for refining and hence has no Ontario refining facility.

Iron Ore Recovery Plant (INCO)

Most of the lung cancer cases are again clustered in the lowest duration categories suggesting, according to the authors, that most of these men are probably longer duration employees who worked only a short time in the Iron plant. There is a non-significant two-fold elevation in the 5 to 9 year exposure period.

Transportation and Maintenance Personnel

All hourly non-sinter employees and foremen from any of the transportation and maintenance, including electrical, departments from INCO's Sudbury and Port Colborne operations were placed in this cohort. A subset from only the mines was also analyzed (Table 39). No elevated risks for lung cancer are seen either in the overall T&M group or the mining subset.


SECTION THREE

Discussion

In general, the results of this comprehensive morbidity study confirm and extend the earlier mortality data regarding elevated lung cancer risk among some subgroups of Ontario nickel workers. Some particular features of this latest study, however, require additional discussion.

Refinement of the cohort:

As noted previously in this Addendum, salaried and non-Ontario employees were removed from the various INCO sub-cohorts and placed in the Transportation, Maintenance and Electrical group (Table 39). The complete lack of any elevated risks for lung cancer in this sub-cohort, especially in the sub-cohort of Mine Transportation and Maintenance workers, underscores the value of removing them from the exposed categories. It is likely that the earlier mortality studies on the INCO cohort underestimated the true risk of lung cancer due to the dilution effect caused by the inclusion of some 12,000(6) out-of-Province, non-exposed or part-time exposed workers and their accompanying person years.

Differences by Decade Hired

As mentioned previously, study results seem to indicate a pattern of increased lung cancer risk in the UGPM group first hired after 1960 (Tables 28 & 30). Although it is generally agreed that with improving ventilation and more modern techniques, dust levels have decreased since the earliest days in the mines, new processes have been introduced. Diesel engines appeared in underground mines in Ontario in the early sixties and were in widespread use by the seventies. Diesel engine exhaust has been designated by the International Agency for Research on Cancer (IARC) as "probably" carcinogenic to humans (IARC Group 2A). The exhaust is a complex mixture of polycyclic aromatic hydrocarbons (PAHs), benzene, soot, nitrites and formaldehyde.

It is probable that this latest follow-up of this cohort has revealed lung cancer cases resulting from these more modern mining exposures. As the authors stated at their presentation to the Panel and stakeholders in Sudbury, the three-fold risk after ten years of exposure "has to be work-related".

Out-of-Province Migration and Other Ore Experience

The McMaster team devoted considerable thought and expertise to what they perceived to be a major problem with differential loss to follow up in this cohort. Dr. Muir and colleagues concluded that nickel workers, and more specifically miners, with short duration of employment, tended to leave the Province in greater numbers than long term employees. Hence underascertainment of cases was greater among short term workers than among those with longer duration of employment. This would tend to lower the SIRs for the short DOE groups and would give the appearance of increasing SIRs by DOE even if no such trend existed.

However, set against this problem is another bias uninvestigated by the McMaster team. From previous analysis of the Mining Master File(MMF), it is known that only approximately 16% of nickel miners worked exclusively in that ore. A further analysis of patterns of work among miners listed in the MMF conducted by ODP staff reveals that miners with only a short time in nickel tended to have more time in other ores than miners with a long time mining nickel(8). Over forty percent of the person years that would be assigned to the 0-1 "years of nickel" group come after five or more years of exposure to other ores. Twenty percent of the person years come after 10 years of exposure to other ores. Of the 6,855 workers who have mined nickel for 5-10 years, 4221 of them (61.6%) show no other ore experience. For the longest term workers, time spent in other ores is minimal.

It is known that working in uranium or gold increases lung cancer risk and hence some of the risk of lung cancer in the short duration nickel miners will be a result of mining these other ores. The effect will be to inflate the SIRs for the short duration of exposure groups relative to the true SIR for mining only nickel, and to reduce the apparent trend with duration of exposure.

In Table 5 the authors attempt to correct for the ascertainment bias by giving adjusted SIRs in the last column to the right. In all but the 10-14 duration of exposure sub-group, the adjusted SIRs are equal to or exceed 100 which could reflect either an underascertainment problem or other ore experience. Table 5 also indicates that for nickel workers after 25 years of exposure, the adjusted SIRs are statistically significant. These men would have had minimal exposure to other ores.

Neither of these problems appears as serious after 15 or more years of nickel mining.

Smoking

As mentioned above, the combined cohort of underground miners showed statistically significant elevated SIRs for lung cancer at 25+ years and significant trends for increased risk with duration of employment >20 years.

In their presentation to stakeholders in September, 1995, the McMaster team presented data that effectively addresses the oft-voiced concern that the excess lung cancer risk among the underground mining cohort can be attributed to smoking. The researchers examined the effect of duration of exposure on lung cancer risk among workers at various ages. When they examined the risk for all miners age 50-59, for example, they found the data showed the same pattern of increasing lung cancer risk with increasing exposure. If smoking were the most significant cause of the excess lung cancer in this cohort, one would expect to see no trend with DOE, in other words, a flat line for the 50-59 year old group. The assumption is that workers of the same age, living in the same locale, and working in the same industry would have similar smoking histories. The results are depicted graphically in Figure 1.

Kusiak et al. reported no association between the proportion of smokers and cumulative exposure to radon-progeny in his uranium miners cohort(4). In other words, there is no evidence that the number of smokers increases with time spent mining.

In addition, Tables 12 - 15 examine several causes of death for various cohort combinations. There is no excess respiratory disease deaths for any group studied. There is a statistically significant excess of cardiovascular disease mortality apparent in the 1964-84 period, which is peculiar since that time period is associated with a general declining trend

in cardiovascular disease mortality in North America. However, the absence of concomitant increased risk of death from respiratory disease suggests that there is no positive confounding by smoking in this cohort.

Smoking is not a satisfactory explanation for the pattern of increased risks seen in this study.


SECTION FOUR

Conclusion

In 1994, the Panel concluded that there was a "probable connection" between lung cancer and all hardrock mining.

The Panel is of the unanimous opinion that the results of this most recent study confirm the Panel's earlier conclusion that there is a "probable connection" between lung cancer and nickel mining.

In addition, the findings support the whole of the hardrock mining report with evidence that working in other ores contributes to lung cancer excess, and that smoking cannot provide a satisfactory explanation for the excesses seen.

The results reconfirm that some sub-groups of workers in the nickel mining industry have statistically significant increases in lung cancer that cannot be attributed to any non-work confounder. This comprehensive report should be of immense help to the Panel and the Board in delineating a reasonable rebuttal matrix for lung cancer among hardrock miners.


REFERENCES

1. Chovil, A.; Sutherland, R. B.;Halliday, M. Respiratory cancer in a cohort of nickel sinter plant workers. British Journal of Industrial Medicine. Vol.38,no.4(1981). p.327-33.

2. Elgie, R.G. [Letter of referral requesting the IDSP to review the Board's current guidelines on the adjudication of claims for lung cancer in the nickel industry]. September 15, 1988.

3. Industrial Disease Standards Panel (IDSP). Report to the Workers' Compensation Board on Lung Cancer in the Hardrock Mining Industry. (IDSP Report No.12). Toronto: Industrial Disease Standards Panel, March 1994.

4. Kusiak, R.A.;Ritchie, A.C.;Muller, J.;Springer, J. Mortality from lung cancer in Ontario uranium miners. British Journal of Industrial Medicine. Vol.50(1993). p.920-28.

5. Muir, D.M.;Julian, J.A. A Study of Cancer Incidence in Ontario Nickel Workers. Report prepared for the Occupational Disease Panel. January 15, 1996.

6. Sutherland, R.B. Summary Report on Respiratory Cancer Mortality 1930-57. Unpublished report to INCO. Port Colborne, Ontario: International Nickel Company of Canada, November 27, 1959.

7. Sutherland, R.B. Mortality Among Sinter Workers. Unpublished report to INCO. Copper Cliff, Ontario: International Nickel Company of Canada, January 17, 1969.

8. Tomlinson, G. [Memorandum to C. Archer]. December 30,1995.


APPENDIX A

GLOSSARY FOR TABLES:

YSFE    Years Since First Exposure

CMF    Comparative Morbidity (or Mortality) Figure

The CMF is the ratio of the weighted incidence rate for the cohort to the weighted incidence rate for the comparison group. The weights are given by the proportion of the reference population in each stratum. With

Ri = reference incidence rate in age-year group i
Wi = proportion of reference population in age-group i
Di = number of cases in study age-year group i
Ni = number of person years in age-year group i

CMF =       the sum of  WiDi / Ni                  the sum of weight* cohort
                                                   incidence rate
           -------------------------    =         -----------------------------
                the sum of Wi Ri                   the sum of weight*         
                                                   reference incidence rate

The study population rates are usually based on rather small numbers of cases, so they are not very "stable" and as a result, a difference of one or two cases in the study population can have a large effect on the CMF.

PcMR    Proportionate Cancer Morbidity (or Mortality) Ratio

Define DS as the number of cancers with the diagnosis of interest in the study group and DR as the number of cancers of the same type in the reference group.

Define TS as the total number of cancers in the study group and TR as the total number in the reference group. TS and TR may be defined to exclude certain cancers known to be associated with exposure, other than the diagnosis of interest.

PcMR is the ratio of the fractions of cancers with the diagnosis of interest in the study and reference groups:

(DS/TS)	        fraction due to diagnosis of interest in study group					
----------  =  ----------------------------------------------------------
(DR/TR)	        fraction due to diagnosis of interest in reference group

Notice that if the type of interest is common, say 1/2 of all cancers in the reference group (DR/TR = 1/2), then the PcMR can only go as large as 2, in the case where all cancers in the study group are due to the diagnosis of interest (DS/TS = 1). This limits the usefulness of the PcMR as a risk estimate to rare cancers.

MOR    Morbidity Odds Ratio

The MOR is the ratio of the odds of observing the cancer of interest in the study group and the odds of observing the cancer of interest in the reference group:

  (DS/(TS-DS))	    odds for cancer of interest in study group	
----------------- = ----------------------------------------------
  (DR/(TR-DR))      odds for cancer of interest in reference group

Since the cancers of interest are subtracted out of total cancers, the upper limit of the MOR is not restricted by the prevalence of the cancer of interest. Further, there is no reason why the TR and TS should be limited to cancer, so long as they do not include other diagnoses that may be in excess in the study group.

Table 5
Adjustment of SIRs to Account for Ascertainment Bias:
1964-84 Lung Cancer (ICD9 162) Incidence for Underground Mining1 by Duration of Exposure
(15 years or more from first exposure)

  Lung Cancer Deaths Lung Cancer SMR Lung Cancer Cases Lung Cancer SIR
Years
Exposed
(DOE)

[1]

Observed
ALL

[2]

Observed
Ex-ONT

[3]

%
Ex-ONT

[4]


  ALL  

[5]

ONT
 only 

[6]

Ratio
 [5]/[6] 

[7]

Observed
ONT

[8]

Observed
Ex-ONT

[9]

Estimated
Ex-ONT

[10]

Observed
SIR

[11]

Adjusted
SIR

[12]
00 < 01 36 11 31 97 65 1.48 33 9 15 68 100
01 < 02 31 8 26 129 93 1.40 28 9 10 88 123
02 - 04 29 8 28 92 65 1.42 33 6 13 80 113
05 - 09 34 6 18 124 99 1.26 34 5 7 95 120
10 - 14 16 1 6 86 77 1.12 20 0 1 84 93
15 - 19 23 1 4 102 95 1.08 34 0 2 116 125
20 - 24 35 1 3 110 104 1.05 44 1 1 108 114
25 - 29 46 2 4 126* 117 1.07 70 0 3 153* 164*
30 - 34 53 2 4 178* 169* 1.05 59 1 2 161* 170*
35 + 20 0 0 160* 159* 1.01 24 0 0 159* 160*
ALL 323 40 12 119* 101 1.17 379 31 54 109 128*

* statistically significant at the 5% level (one sided)

1 underground production mining (hourly and foremen) for INCO and underground mining (exposed) for Falconbridge

Table 12
Combined Cohort: Never Sinter
Cause-Specific Standardized Mortality Ratios (SMR) and 95% Confidence Intervals
by Follow-up Period

  1950-63 Period 1964-84 Period
Cause of Death   Obs     Exp     SMR     Obs     Exp     SMR  
All Causes
ICD 0-999
1523 1566.7 97
92 - 102
6984 6464.8 108
106 - 111
Circulatory Disease
ICD 390-459
647 710.7 91
84 - 98
3192 2988.9 107
103 - 111
Accidents, Violence
ICD 800-999
429 336.5 128
116 - 140
1222 853.2 143
135 - 152
Cancer
ICD 140-208
271 253.3 107
95 - 121
1544 1504.5 103
98 - 108
Respiratory Disease
ICD 460-519
48 66.3 72
53 - 96
359 350.7 102
92 - 114
Cirrhosis of Liver
ICD 571
14 22.9 61
33 - 103
176 186.5 94
81 - 109
Nasal-related Cancer
ICD 147, 160, 170.0
4 3.1 128
35 - 328
14 9.4 149
81 - 250
Larynx Cancer
ICD 161
4 3.0 132
36 - 337
20 22.2 90
55 - 139
Lung Cancer
ICD 162
75 54.3 138
109 - 173
555 493.1 113
103 - 122
YSFE: 0 - 14 years
87 - 256
15 9.7 155
87 - 256
20 18.5 108
66 - 167
YSFE: 15 + years 60 44.7 134
103 - 173
535 474.6 113
103 - 123

Table 13
Combined Cohort: Any Sinter Cause-Specific Standardized Mortality Ratios (SMR) and 95% Confidence Intervals
by Follow-up Period

  1950-63 Period 1964-84 Period
Cause of Death Obs Exp SMR Obs Exp SMR
All Causes
ICD 0-999
193 188.5 102
88 - 118
779 647.7 120
112 - 129
Circulatory Disease
ICD 390-459
79 89.2 89
70 - 110
373 312.2 120
108 - 132
Accidents, Violence
ICD 800-999
38 36.2 105
74 - 144
84 68.8 122
97 - 151
Cancer
ICD 140-208
54 31.5 172
129 - 224
234 153.0 153
134 - 174
Respiratory Disease
ICD 460-519
6 8.3 73
27 - 158
28 36.4 77
51 - 111
Cirrhosis of Liver
ICD 571
1 2.6 38
1 - 213
23 19.2 120
76 - 179
Nasal-related Cancer
ICD 147, 160, 170.0
10 0.4 2643
1267 - 4860
20 1.0 2105
1286 - 3251
Larynx Cancer
ICD 161
1 0.4 255
7 - 1424
0 2.3 0
0 - 160
Lung Cancer
ICD 162
22 6.9 318
199 - 482
116 50.4 230
190 - 276
YSFE: 0 - 14 years 2 1.6 124
15 - 449
3 1.9 155
32 - 453
YSFE: 15 + years 20 5.3 377
230 - 582
113 48.5 233
192 - 280

Table 14
Combined Cohort: UG Production Mining (Never Sinter)
Cause-Specific Standardized Mortality Ratios (SMR) and 95% Confidence Intervals
by Follow-up Period

  1950-63 Period 1964-84 Period
Cause of Death Obs Exp SMR Obs Exp SMR
All Causes
ICD 0-999
762 751.1 102
94 - 109
4088 3617.1 113
110 - 117
Circulatory Disease
ICD 390-459
274 316.9 87
77 - 97
1804 1650.4 109
104 - 115
Accidents, Violence
ICD 800-999
289 185.9 155
138 - 174
824 491.7 168
156 - 179
Cancer
ICD 140-208
119 117.9 101
84 - 121
890 852.6 104
98 - 112
Respiratory Disease
ICD 460-519
18 29.8 61
36 - 96
194 186.9 104
90 - 120
Cirrhosis of Liver
ICD 571
6 11.9 50
19 - 110
94 111.0 85
68 - 104
Nasal-related Cancer
ICD 147, 160, 170.0
2 1.6 128
16 - 464
7 5.5 128
51 - 262
Larynx Cancer
ICD 161
1 1.4 73
2 - 404
13 12.9 101
54 - 173
Lung Cancer
ICD 162
33 25.0 132
91 - 185
334 283.2 118
106- 131
YSFE: 0 - 14 years 8 5.5 146
63 - 288
12 11.3 106
55 - 185
YSFE: 15 + years 25 19.5 128
83 - 187
322 271.9 118
106 - 132

Table 15
Combined Sudbury Cohort: Never UG Production Mining (Never Sinter)
Cause-Specific Standardized Mortality Ratios (SMR) and 95% Confidence Intervals
by Follow-up Period

  1950-63 Period 1964-84 Period
Cause of Death Obs Exp SMR Obs Exp SMR
All Causes
ICD 0-999
637 652.5 98
90 - 106
2409 2264.1 106
102 - 111
Circulatory Disease
ICD 390-459
307 321.0 96
85 - 107
1143 1070.9 107
101 - 113
Accidents, Violence
ICD 800-999
124 113.1 110
91 - 131
338 278.4 121
109 - 135
Cancer
ICD 140-208
124 109.6 113
94 - 135
552 520.6 106
97 - 115
Respiratory Disease
ICD 460-519
25 29.5 85
55 - 125
145 130.9 111
94 - 130
Cirrhosis of Liver
ICD 571
8 8.9 90
39 - 176
64 60.0 107
82 - 136
Nasal-related Cancer
ICD 147, 160, 170.0
1 1.3 80
2 - 445
5 3.1 162
53 - 378
Larynx Cancer
ICD 161
3 1.4 221
46 - 645
4 7.5 53
15 - 136
Lung Cancer
ICD 162
36 24.0 150
105 - 208
191 168.2 114
98 - 131
YSFE: 0 - 14 years 7 3.9 180
73 - 372
9 6.4 141
65 - 268
YSFE: 15 + years 29 20.1 144
97 - 207
182 161.8 113
97 - 130

Table 21
1964-89 Lung Cancer (ICD9 162) Risk Estimates and 95% Confidence Intervals:
(a) Sudbury Area Cohorts (Never Sinter) by Duration of Exposure
(15 years or more since first exposed)

  INCO: hourly and foremen Falconbridge: exposed
DOE
[1]
OBS
[2]
SIR
[3]
CMF
[4]
PcMR
[5]
MOR
[6]
OBS
[7]
SIR
[8]
CMF
[9]
PcMR
[10]
MOR
[11]
00 < 01 33 1(12) 54
37 - 76
37
24 - 56
95
65 - 133
90
62 - 127
6 1(4) 52
19 - 114
30
13 - 70
99
36 - 216
88
32 - 191
01 < 02 45 (10) 76
56 - 102
55
35 - 89
124
91 - 166
125
91 - 168
8 (3) 86
37 - 169
62
29 - 136
132
57 - 259
138
60 - 272
02 - 04 65 (6) 80
61 - 101
62
45 - 87
114
88 - 145
118
91 - 150
8 (3) 57
24 - 112
65
26 - 164
84
36 - 166
74
32 - 146
05 - 09 42 (8) 70
51 - 95
62
37 - 102
97
70 - 131
94
67 - 126
10 (2) 92
44 - 169
119
40 - 349
139
67 - 256
143
69 - 264
10 - 14 23 (3) 68
43 - 103
63
38 - 105
85
54 -128
80
51 - 120
10 (1) 106
51 - 196
74
35 - 156
122
58 - 224
116
56 -213
15 - 19 53 (2) 105
79 - 138
74
54 - 102
97
73 - 127
98
74 - 129
15 (1) 133
75 - 220
155
81 - 295
129
72 - 213
130
73 - 215
20 - 24 83 (3) 105
83 - 130
105
83 - 132
112
89 - 139
111
89 - 138
14 (0) 103
56 - 173
74
44 - 125
112
61 - 187
118
65 - 198
25 - 29 127 (3) 109
91 - 130
105
87 -126
115
96 - 137
126
105 - 150
14 (0) 105
58 - 177
84
47 - 149
128
70 - 214
133
73 - 224
30 - 34 152 (1) 117
99 - 137
105
89 - 124
114
97 - 134
123
104 - 144
16 (0) 166
95 - 270
165
98 - 276
130
75 - 212
153
88 - 249
35 + 121 (0) 134
112 - 161
150
110 - 205
124
103 - 148
134
111 - 160
7 (0) 118
47 - 242
94
42 - 213
94
38 - 194
125
50 - 258
ALL 744 (48) 98
91 - 105
101
93 - 109
111
103 - 120
116
107 - 124
108 (14) 99
81 - 120
99
78 - 126
118
96 - 142
122
100 - 147

Table 22
1964-89 Lung Cancer (ICD9 162) Risk Estimates and 95% Confidence Intervals:
(b) INCO Port Colborne Cohort (Never Sinter) by Duration of Exposure
(15 years or more since first exposed)

  INCO Port Colborne: hourly and foremen
DOE
[1]
OBS
[2]
SIR
[3]
CMF
[4]
PcMR
[5]
MOR
[6]
00 < 01 1 1(0) 37
1 - 205
19
3 - 136
59
2 - 330
50
1 -281
01 < 02 3 (0) 167
34 - 487
966
142 - 6574
99
20 - 289
99
20 - 290
02 - 04 3 (0) 83
17 - 242
31
10 - 101
81
17 - 236
71
15 - 208
05 - 09 2 (0) 59
7 - 214
26
7 - 104
65
8 - 236
62
8 - 224
10 - 14 1 (0) 38
1 - 212
27
4 - 192
61
2 - 337
52
1 - 292
15 - 19 4 (0) 75
20 - 191
75
25 - 225
118
32 - 302
187
51 - 479
20 - 24 9 (0) 122
56 - 231
137
69 - 270
117
54 - 222
166
76 - 316
25 - 29 9 (0) 111
51 - 210
95
49 - 184
131
60 - 248
148
68 - 281
30 - 34 9 (0) 99
45 - 188
104
53 - 206
102
47 - 194
84
38 - 159
35 + 3 (0) 39
8 - 114
37
11 - 126
57
12 - 166
40
8 -117
ALL 44 (0) 85
62 - 114
83
61 - 114
97
71 - 131
95
69 - 128

1 number of ex-ONT cases in the brackets

Table 23
1964-89 Lung Cancer (ICD9 162) Risk Estimates and 95% Confidence Intervals:
(c) INCO Sintering - Copper Cliff and Port Colborne by Duration of Exposure
(10 /15 years or more since first exposed)

  Copper Cliff Sinter Plant: hourly (10 or more YSFE) Port Colborne L,C&S: hourly (15 or more YSFE)
DOE OBS SIR
[2]
CMF
[3]
PcMR
[4]
MOR
[5]
OBS
[6]
SIR
[7]
CMF
[8]
PcMR
[9]
MOR
[10]
< 1 mo 2 1 (0) 47
6 - 169
54
13 - 215
64
8 - 230
51
6 - 185
8 1 (0) 133
57 - 262
161
68 - 379
137
59 - 269
146
63 - 287
1 < 3 mo 14 (0) 193
105 - 323
299
117 - 768
194
106 - 325
293
160 - 491
5 (0) 83
27 - 195
135
49 - 372
86
28 - 200
136
44 - 317
3 < 6 mo 7 (0) 90
36 - 186
88
35 - 222
117
47 - 242
127
51 - 262
9 (0) 228
104 - 433
226
106 - 484
220
101 - 417
448
205 - 850
6 < 12 mo 15 (1) 209
117 - 344
152
85 - 271
201
113 - 332
334
187 - 551
9 (0) 186
85 - 352
231
106 - 503
203
93 - 385
368
168 - 698
01 < 02 12 (0) 228
118 - 398
164
88 - 307
168
87 - 294
291
151 - 509
5 (0) 126
41 - 294
117
49 - 282
108
35 - 252
143
46 - 333
02 - 04 12 (1) 308
159 - 538
368
124 - 1094
236
122 - 413
528
273 - 921
9 (1) 138
63 - 262
147
73 - 299
134
61 - 254
125
57 - 237
05 - 09 15 (5) 457
256 - 754
285
162 - 502
268
150 - 443
997
558 - 1644
16 (0) 298
170 - 484
265
160 - 441
181
104 - 295
290
166 - 471
10 - 19 31 (0) 729
496 - 1035
560
390 - 804
295
200 - 418
1721
1170 - 2443
4 (0) 167
45 - 427
275
75 - 1012
140
38 - 360
235
64 - 602
20 +           8 (0) 400
173 - 788
454
183 - 1127
168
73 - 331
232
100 - 457
ALL 108 (7) 250
205 - 302
206
160 - 265
207
170 - 250
380
312 - 459
73 (1) 178
139 - 224
196
153 - 252
152
119 - 191
209
163 - 262

1 number of ex-ONT cases in the brackets

Table 24
1964-89 Lung Cancer (ICD9 162) Risk Estimates and 95% Confidence Intervals:
(d) Copper Cliff Sinter Plant - Early versus Late First Exposure by Duration of Exposure
(10 years or more since first exposed)

  First Exposed before 1952 (hourly) First Exposed 1952 or later (hourly)
DOE
[1]
OBS
[2]
SIR
[3]
CMF
[4]
PcMR
[5]
MOR
[6]
OBS
[7]
SIR
[8]
CMF
[9]
PcMR
[10]
MOR
[11]
< 1 mo 2 1(0) 53
7 - 193
64
16 - 258
68
8 - 246
55
7 - 199
2 1(0) 88
11 - 317
440
67 - 2878
147
18 - 532
143
17 - 515
1 < 3 mo 12 (0) 214
111 - 374
195
105 - 361
198
102 - 346
328
169 - 572
         
3 < 6 mo 6 (0) 108
40 - 235
101
40 - 259
121
44 - 262
138
51 - 301
2 (0) 51
6 - 182
12
3 - 47
93
11 - 334
73
9 - 265
6 < 12 mo 14 (1) 262
143 - 440
191
107 - 338
223
122 - 375
477
261 - 801
         
01 < 02 9 (0) 234
107 - 445
143
71 - 288
186
85 - 352
421
192 - 799
3 (0) 210
43 - 613
440
105 - 1849
131
27 - 383
151
31 - 442
02 - 04 10 (1) 445
213 - 818
498
204 - 1216
245
118 - 451
526
252 - 968
2 (0) 121
15 -439
112
28 - 453
200
24 - 722
533
65 - 1925
05 - 09 10 (5) 490
235 - 901
326
166 - 642
252
121 - 462
1272
610 - 2340
5 (0) 337
110 - 787
392
113 - 1362
269
87 - 627
695
226 - 1622
10 + 31 (0) 773
525 - 1097
620
430 - 895
302
205 - 429
1721
1170 - 2443
         
ALL 94 (7) 290
235 - 355
217
170 - 276
217
175 - 265
444
358 - 543
14 (0) 130
71 - 217
292
88 - 968
161
88 - 271
194
106 - 326

1 number of ex-ONT cases in the brackets

Table 25
1964-89 Lung Cancer (ICD9 162) Risk Estimates and 95% Confidence Intervals:
(e) Other Sintering - Falconbridge and Coniston Sinter Plants (Never CCSP or L,C&S Exposed) by Duration of Exposure
(15 years of more since first exposed)

  Falconbridge Sinter Plant INCO Coniston Sinter Plant: hourly
DOE
[1]
OBS
[2]
SIR
[3]
CMF
[4]
PcMR
[5]
MOR
[6]
OBS
[7]
SIR
[8]
CMF
[9]
PcMR
[10]
MOR
[11]
< 3 mo 6 1(0) 149
55 - 325
109
41 - 290
171
63 - 371
200
73 - 435
         
3 < 6 mo 5 (0) 169
55 - 395
205
73 - 581
173
56 - 404
221
72 - 517
1 1(0) 79
2 - 439
364
51 - 2585
103
3 - 571
94
2 - 524
6 < 12 mo 6 (0) 104
38 - 225
68
29 - 156
160
59 - 349
163
60 - 354
         
01 < 02 9 (0) 124
57 - 236
108
48 - 247
112
51 - 212
103
47 - 196
2 (0) 179
22 - 647
72
15 - 340
130
16 - 469
121
15 - 437
02 - 04 12 (0) 180
93 - 315
182
92 - 359
134
69 - 234
143
74 - 251
         
05 - 09 3 (0) 93
19 - 272
93
29 - 300
80
17 - 234
70
14 - 203
2 (0) 461
56 - 1665
495
118 - 2084
260
32 - 940
491
60 - 1774
10 + 4 (0) 194
53 - 496
129
48 - 345
143
39 - 366
171
47 - 437
2 (0) 162
20 - 585
106
26 - 428
92
11 - 332
66
8 - 239
ALL 45 (0) 141
103 - 189
151
106 - 215
134
97 - 179
138
100 - 184
7 (0) 173
69 - 356
155
70 - 344
128
52 - 264
114
46 - 234

1 number of ex-ONT cases in the brackets

Table 26
1964-89 Lung Cancer (ICD9 162) Risk Estimates and 95% Confidence Intervals:
(f) INCO - Falconbridge Underground Production Mining2 (Never Sinter)
by Duration of Exposure
(15 years or more since first exposed)

  INCO - Falconbridge Underground Mining
DOE
[1]
OBS
[2]
SIR
[3]
CMF
[4]
PcMR
[5]
MOR
[6]
00 < 01 51 1(11) 62
46 - 82
58
40 - 83
94
70 - 124
90
67 - 118
01 < 02 43 (9) 79
57 - 106
116
54 - 246
123
89 - 166
128
93 - 173
02 - 04 53 (8) 77
58 - 100
82
57 - 119
109
82 - 142
114
85 - 149
05 - 09 55 (6) 97
73 - 127
92
64 - 134
117
88 - 152
125
94 - 163
10 - 14 31 (1) 86
58 - 122
84
56 - 126
101
69 - 143
99
67 - 140
15 - 19 49 (1) 118
87 - 156
115
80 - 165
115
85 - 152
109
81 - 144
20 - 24 58 (1) 106
81 - 137
113
82 - 155
114
87 - 148
122
93 - 158
25 - 29 89 (1) 142
114 - 174
136
104 - 178
133
107 - 163
148
119 - 183
30 - 34 79 (1) 139
110 - 173
130
103 - 165
127
100 - 158
138
110 - 172
35 + 40 (0) 171
122 - 233
294
140 - 614
129
92 - 176
142
102 - 194
ALL 548 (39) 102
94 - 111
112
100 - 127
117
107 - 127
122
112 - 133

1 number of ex-ONT cases in the brackets

2 underground production mining (hourly and foremen) for INCO and underground mining (exposed) for Falconbridge

Table 27
1964-89 Lung Cancer (ICD9 162) Risk Estimates and 95% Confidence Intervals:
(g) INCO and Falconbridge Underground Mining (Never Sinter) by Duration of Exposure
(15 years or more since first exposed)

  INCO Underground Production Mining: hourly and foremen Falconbridge Underground Mining: exposed
DOE
[1]
OBS
[2]
SIR
[3]
CMF
[4]
PcMR
[5]
MOR
[6]
OBS
[7]
SIR
[8]
CMF
[9]
PcMR
[10]
MOR
[11]
00 < 01 52 1(8) 66
49 - 86
61
42 - 87
98
73 - 129
95
71 - 124
6 1(4) 59
22 - 129
31
14 - 71
107
39 - 233
98
36 - 213
01 < 02 43 (7) 82
59 - 110
118
56 - 249
119
86 - 160
121
88 - 164
7 (3) 94
38 - 194
61
27 - 137
183
73 - 376
237
95 - 488
02 - 04 55 (6) 86
65 - 111
80
58 - 109
118
89 - 154
125
94 - 162
6 (1) 57
21 - 124
92
28 - 302
74
27 - 161
69
25 - 151
05 - 09 47 (4) 95
70 - 126
90
61 - 134
106
78 - 141
108
80 - 144
9 (2) 106
49 - 202
141
48 - 419
183
84 - 347
256
117 - 487
10 - 14 23 (1) 81
51 - 121
81
52 - 127
94
59 - 141
93
59 - 139
7 (0) 100
40 - 205
55
26 - 118
119
48 - 245
101
41 - 208
15 - 19 37 (0) 108
76 - 149
107
71 - 162
110
77 - 151
104
73 - 144
11 (1) 148
74 - 264
143
70 - 292
120
60 - 215
116
58 - 208
20 - 24 51 (1) 111
82 - 145
114
82 - 158
116
87 - 153
123
92 - 162
12 (0) 135
70 - 236
144
62 - 336
140
72 - 244
197
102 - 343
25 - 29 71 (1) 132
103 - 167
132
98 - 178
129
101 - 163
143
111 - 180
14 (0) 158
87 - 266
118
68 - 204
131
72 - 220
138
76 - 232
30 - 34 65 (1) 133
103 - 169
122
94 - 158
120
92 - 152
128
99 - 163
13 (0) 184
98 - 314
206
113 - 379
183
98 - 313
255
136 - 435
35 + 36 (0) 178
125 - 246
327
150 - 712
138
96 - 190
157
110 - 217
4 (0) 135
37 - 345
124
43 - 360
92
25 - 237
85
23 - 218
ALL 480 (29) 101
92 - 110
112
98 - 127
115
105 - 126
119
109 - 130
89 (11) 113
91 - 139
122
88 - 168
131
105 - 161
140
112 - 172

1 number of ex-ONT cases in the brackets

Table 28
1964-89 Lung Cancer (ICD9 162) SIRs and CMFs:
(h) INCO Underground Production Mining: hourly and foremen (Never Sinter)
by Decade of First Exposure and Duration of Exposure
(15 years of more since first exposed)

  First Exposed before 1930 First Exposed 1930-39 First Exposed 1940-49 First Exposed 1950-59 First Exposed 1960 or later
DOE
[1]
OBS
[2]
SIR
[3]
CMF
[4]
OBS
[5]
SIR
[6]
CMF
[7]
OBS
[8]
SIR
[9]
CMF
[10]
OBS
[11]
SIR
[12]
CMF
[13]
OBS
[14]
SIR
[15]
CMF
[16]
00 < 01 3 1(0) 245 151 6 1(1) 73 44 21 1(3) 78 56 19 1(3) 53 36 3 1(1) 46 3
01 < 02 2 (0) 300 207 2 (0) 47 35 14 (3) 88 75 16 (3) 59 77 9 (1) 195* 263
02 - 04 3 (0) 297 400* 10 (0) 118 74 28 (4) 107 95 10 (2) 43 21 4 (0) 76 32
05 - 09 1 (0) 93 316 11 (2) 94 84 16 (2) 106 76 18 (0) 93 54 1 (0) 43 74
10 - 14 3 (0) 195 269 4 (0) 49 30 6 (0) 79 169 8 (1) 87 92 2 (0) 105 252
15 - 19 1 (0) 67 59 6 (0) 101 173 14 (0) 148 131 10 (0) 73 42 6 (0) 169 93
20 - 24 4 (0) 208 135 7 (0) 85 68 22 (0) 115 110 17 (0) 109 268 1 (0) 94 16
25 - 29 4 (0) 121 79 21 (1) 159* 174* 28 (0) 124 115 18 (0) 124 105  
30 - 34 12 (0) 205* 131 22 (1) 128 105 17 (0) 99 62 14 (0) 162* 321*  
35 + 11 (0) 202* 252* 13 (1) 155* 239 12 (0) 187* 211*    
ALL 44 (0) 187* 170* 102 (6) 109 91 178 (12) 107 94 130 (9) 78 78 26 (2) 103 70

1 number of ex-ONT cases in the brackets

* statistically significant at the 5% level (one-sided)

Table 30
1964-89 Lung Cancer (ICD9 162) SIRs and CMFs:
(j) Falconbridge Underground Mining (Never Sinter)
by Decade by First Exposure and Duration of Exposure
(15 years or more since first exposed)

  First Exposed before 1940 First Exposed 1940-49 First Exposed 1950-59 First Exposed 1960 or later
DOE
[1]
OBS
[2]
SIR
[3]
CMF
[4]
OBS
[5]
SIR
[6]
CMF
[7]
OBS
[8]
SIR
[9]
CMF
[10]
OBS
[11]
SIR
[12]
CMF
[13]
00 < 01 0 1(0) 0 0 1 1(0) 63 47 4 1(3) 61 27 1 1(1) 59 104
01 < 02 1 (0) 775 584 3 (1) 203 156 3 (2) 66 31 0 (0) 0 0
02 - 04 1 (0) 352 132 3 (0) 114 91 2 (1) 36 27 0 (0) 0 0
05 - 09 0 (0) 0 0 1 (1) 38 75 7 (1) 165 182 1 (0) 88 25
10 - 14 0 (0) 0 0 0 (0) 0 0 3 (0) 79 59 4 (0) 319* 144
15 - 19 1 (0) 198 174 2 (1) 140 92 2 (0) 61 161 6 (0) 269* 268*
20 - 24 0 (0) 0 0 3 (0) 121 111 8 (0) 147 106 1 (0) 131 44
25 - 29 0 (0) 0 0 8 (0) 199* 128 6 (0) 157 109  
30 - 34 4 (0) 217 159 8 (0) 215* 236* 1 (0) 67 26  
35 + 2 (0) 81 45 2 (0) 398 175    
ALL 9 (0) 118 108 31 (3) 141* 140 36 (7) 93 69 13 (1) 124 67

1 number of ex-ONT cases in the brackets

* statistically significant at the 5% level (one-sided)

Table 32
1964-89 Lung Cancer (ICD9 162) Risk Estimates and 95% Confidence Intervals:
(l) INCO - Falconbridge Milling (Never Sinter)
by Duration of Exposure
(15 years or more since first exposed)

  INCO - Falconbridge Mills: hourly, foremen and exposed
DOE
[1]
OBS
[2]
SIR
[3]
CMF
[4]
PcMR
[5]
MOR
[6]
00 < 01 31 1(1) 93
63 - 132
96
56 - 165
113
77 - 161
116
79 - 165
01 < 02 18 (1) 171
101 - 270
150
82 - 275
164
97 - 260
212
126 - 335
02 - 04 15 (0) 116
65 - 192
156
66 - 367
121
68 - 200
132
74 - 217
05 - 09 7 (0) 83
33 - 170
87
39 - 195
109
44 - 224
88
35 - 180
10 - 14 4 (0) 86
24 - 221
238
57 - 1000
106
29 - 271
97
26 - 248
15 - 19 5 (0) 109
35 - 253
159
65 - 386
85
28 - 199
82
27 - 191
20 - 24 10 (0) 163
78 - 300
156
82 - 298
128
61 - 235
148
71 - 272
25 - 29 5 (0) 70
23 - 163
117
33 - 408
95
31 - 222
116
38 - 271
30 - 34 3 (0) 63
13 - 184
62
19 - 196
64
13 - 187
65
13 - 190
35 + 6 (0) 153
56 - 333
142
58 - 350
108
40 -236
115
42 - 249
ALL 104 (2) 108
88 - 131
109
87 - 137
115
94 - 140
121
99 - 147

1 number of ex-ONT cases in the brackets

Table 33
1964-89 Lung Cancer (ICD9 162) Risk Estimates and 95% Confidence Intervals:
(m) INCO and Falconbridge Milling (Never Sinter) by Duration of Exposure
(15 years or more since first exposed)

  INCO Mills: hourly and foremen Falconbridge Mills: exposed
DOE
[1]
OBS
[2]
SIR
[3]
CMF
[4]
PcMR
[5]
MOR
[6]
OBS
[7]
SIR
[8]
CMF
[9]
PcMR
[10]
MOR
[11]
00 < 01 30 1(1) 99
67 - 141
101
58 - 173
113
76 - 161
114
77 - 163
         
01 < 02 16 (0) 180
103 - 293
155
84 - 287
173
99 - 281
229
131 - 372
5 1(1) 73
24 - 171
87
20 - 331
99
32 - 232
95
31 - 223
02 - 04 14 (0) 132
72 - 221
182
79 - 420
135
74 - 227
165
90 - 278
         
05 - 09 7 (0) 99
40 - 204
107
48 - 240
123
50 -254
104
42 - 214
1 (0) 45
1 - 252
101
14 - 718
87
2 - 484
62
2 - 344
10 - 14 3 (0) 81
17 - 236
242
55 - 1074
89
18 - 259
80
16 - 233
         
15 - 19 5 (0) 134
43 - 312
193
80 - 468
89
29 - 207
82
27 - 191
         
20 - 24 9 (0) 175
80 - 333
167
82 - 338
137
63 - 260
175
80 - 333
         
25 - 29 5 (0) 82
27 - 190
142
40 - 508
109
36 - 255
134
44 - 313
1 (0) 23
1 - 128
74
10 - 523
22
1 - 120
21
1 - 116
30 - 34 3 (0) 72
15 - 210
71
22 - 228
82
17 - 239
102
21 - 298
         
35 + 6 (0) 209
77 - 455
206
86 - 493
147
54 - 321
138
51 - 300
         
ALL 98 (1) 118
96 - 144
120
96 - 151
123
100 - 150
132
107 - 160
7 (1) 52
21 - 108
43
20 - 92
65
26 - 133
60
24 - 124

1 number of ex-ONT cases in the brackets

Table 34
1964-89 Lung Cancer (ICD9 162) Risk Estimates and 95 % Confidence Intervals:
(n) INCO - Falconbridge Smelting (Never Sinter)
by Duration of Exposure
(15 years or more since first exposed)

  INCO - Falconbridge Smelters: hourly, foremen and exposed
DOE
[1]
OBS
[2]
SIR
[3]
CMF
[4]
PcMR
[5]
MOR
[6]
00 < 01 66 1(6) 79
61 - 100
69
52 - 92
100
77 - 127
94
73 - 120
01 < 02 32 (4) 107
73 - 151
172
90 - 328
138
94 - 195
148
101 - 209
02 - 04 42 (2) 93
67 - 126
87
57 - 134
113
82 - 153
120
86 - 162
05 - 09 25 (1) 76
49 - 112
83
50 - 138
82
53 - 121
80
52 - 118
10 - 14 21 (1) 118
73 - 181
100
63 - 158
112
69 - 171
118
73 - 180
15 - 19 20 (1) 93
57 - 144
91
56 - 147
88
54 - 135
91
56 - 141
20 - 24 29 (1) 94
63 - 135
84
58 - 121
93
62 - 133
92
62 - 132
25 - 29 26 (2) 89
58 - 131
98
65 - 149
109
71 - 159
122
80 - 179
30 - 34 32 (0) 111
76 - 156
103
72 - 148
106
73 - 150
114
78 - 160
35 + 25 (0) 101
66 - 149
86
51 - 144
124
80 - 183
131
85 - 193
ALL 318 (18) 92
82 - 103
91
81 - 103
105
93 - 117
107
95 - 119

1 number of ex-ONT cases in the brackets

Table 35
1964-89 Lung Cancer (ICD9 162) Risk Estimates and 95% Confidence Intervals:
(o) INCO Copper Cliff and Coniston Smelters (Never Sinter) by Duration of Exposure
(15 years or more since first exposed)

  Copper Cliff Smelter: hourly and foremen Coniston Smelter: hourly and foremen
DOE
[1]
OBS
[2]
SIR
[3]
CMF
[4]
PcMR
[5]
MOR
[6]
OBS
[7]
SIR
[8]
CMF
[9]
PcMR
[10]
MOR
[11]
00 < 01 69 1(8) 83
64 - 105
109
56 - 213
103
80 - 130
99
77 - 125
9 1(0) 76
35 - 144
197
49 - 787
100
46 - 190
91
42 - 173
01 < 02 32 (4) 110
75 - 155
161
91 - 284
138
94 - 194
153
104 - 215
3 (0) 67
14 - 195
28
9 - 90
102
21 - 299
89
18 - 259
02 - 04 42 (2) 97
70 - 131
83
58 - 119
112
81 - 152
118
85 - 159
5 (1) 77
25 - 179
60
20 - 182
114
37 - 266
185
60 - 432
05 - 09 25 (0) 80
52 - 118
87
54 - 140
86
56 - 127
85
55 - 125
3 (0) 73
15 - 212
142
34 - 601
54
11 - 158
47
10 - 137
10 - 14 17 (0) 102
59 - 163
87
52 - 145
106
62 - 170
113
66 - 181
3 (1) 108
22 - 316
100
31 - 327
127
26 - 370
121
25 - 354
15 - 19 21 (1) 107
66 - 163
103
65 - 165
98
61 - 150
105
65 - 160
2 (0) 58
7 - 208
23
6 - 92
56
7 - 201
52
6 - 189
20 - 24 27 (1) 98
65 - 143
91
62 - 134
101
67 - 148
105
69 - 153
1 (0) 35
1 - 197
18
3 - 127
38
1 - 211
31
1 - 172
25 - 29 24 (2) 91
59 - 136
101
65 - 157
114
73 - 169
129
82 - 191
3 (0) 181
37 - 530
171
45 - 655
114
23 - 332
94
19 - 274
30 - 34 27 (0) 112
74 - 163
107
107 - 158
112
74 - 163
128
84 - 186
2 (0) 74
9 - 268
32
8 - 128
69
8 - 248
55
7 - 199
35 + 22 (0) 107
67 - 162
88
52 - 149
122
76 - 184
130
82 - 198
2 (0) 74
9 - 269
100
25 - 402
112
14 - 406
101
12 - 363
ALL 306 (18) 95
85 - 106
94
83 - 107
108
96 - 121
112
100 - 125
33 (2) 77
53 - 107
80
54 - 119
87
60 - 123
81
56 - 114

1 number of ex-ONT cases in the brackets

Table 36
1964-89 Lung Cancer (ICD9 162) Risk Estimates and 95% Confidence Intervals:
(p) Falconbridge Smelter (Two Versions) by Duration of Exposure
(15 years or more since first exposed)

  Falconbridge Smelter (Never Sinter) Falconbridge Smelter (including FALC Sinter Plant)
DOE
[1]
OBS
[2]
SIR
[3]
CMF
[4]
PcMR
[5]
MOR
[6]
OBS
[7]
SIR
[8]
CMF
[9]
PcMR
[10]
MOR
[11]
00 < 01           11 1(0) 125
63 - 224
79
40 - 156
170
85 - 305
181
90 - 324
01 < 02 0 1(0) 0
0 - 195
? 0
0 - 516
0
0 - 301
2 (0) 43
5 - 155
25
6 - 101
47
6 - 171
35
4 - 127
02 - 04           9 (0) 177
81 - 335
214
87 - 530
185
85 - 351
235
107 - 446
05 - 09           9 (0) 294
135 - 558
293
131 - 655
182
83 - 346
265
121 - 503
10 - 14 3 (0) 194
40 - 567
66
21 - 205
164
34 - 480
87
2 - 484
2 (0) 75
9 - 270
45
10 - 202
143
17 - 516
163
20 - 590
15 - 19           2 (0) 83
10 - 299
30
8 - 122
54
7 - 193
47
6 - 169
20 - 24           4 (0) 135
37 - 347
119
42 - 340
213
58 - 544
273
74 - 698
25 - 29 0 (0) 0
0 - 212
? 0
0 - 263
0
0 - 245
3 (0) 86
18 - 250
58
17 - 194
66
14 - 194
53
11 - 156
30 - 34           6 (0) 203
75 - 443
205
79 - 530
116
43 - 253
148
55 - 323
35 +           1 (0) 76
2 - 422
37
5 - 260
75
2 - 418
63
2 - 353
ALL 3 (0) 58
12 - 169
66
21 - 205
76
16 - 222
77
16 - 226
49 (0) 131
97 - 173
132
95 - 182
127
94 - 168
132
97 - 174

1 number of ex-ONT cases in the brackets

Table 37
1964-89 Lung Cancer (ICD9 162) Risk Estimates and 95% Confidence Intervals:
(q) INCO Copper Cliff Copper Refinery and Tankhouse (Never Sinter) by Duration of Exposure
(15 years or more since first exposed)

  Copper Refinery: hourly and foremen Copper Refinery Tankhouse: hourly and foremen
DOE
[1]
OBS
[2]
SIR
[3]
CMF
[4]
PcMR
[5]
MOR
[6]
OBS
[7]
SIR
[8]
CMF
[9]
PcMR
[10]
MOR
[11]
00 < 01 16 1(1) 93
53 - 151
65
37 - 115
135
77 - 219
144
82 - 234
8 1(1) 126
54 - 248
210
64 - 682
136
59 - 267
137
59 - 269
01 < 02 9 (1) 158
72 - 301
176
66 - 469
154
71 - 293
178
81 - 337
11 (0) 64
2 - 354
116
16 - 824
57
2 - 320
43
1 - 239
02 - 04 4 (0) 70
19 - 180
100
32 - 307
97
26 - 248
91
25 - 232
3 (0) 175
36 - 511
354
71 - 1769
168
35 - 491
188
39 - 549
05 - 09 3 (0) 71
15 - 208
70
22 - 219
84
17 - 244
79
16 - 230
2 (0) 123
15 - 445
103
26 - 414
140
17 - 506
126
15 - 454
10 - 14 1 (1) 30
1 - 169
41
6 - 291
37
1 - 209
30
1 - 166
0 (0) 0
0 - 243
0 0
0 - 510
0
0 - 438
15 - 19 4 (0) 96
26 - 246
74
27 - 207
102
28 - 260
110
30 - 283
1 (0) 73
2 - 404
551
78 - 3911
49
1 - 275
37
1 - 208
20 - 24 4 (1) 75
21 - 193
54
20 - 145
82
22 - 209
71
19 - 182
2 (0) 156
19 - 562
131
32 - 545
166
20 - 601
167
20 - 604
25 - 29 11 (1) 173
86 - 309
143
76 - 267
154
77 - 276
165
82 - 294
1 (0) 73
2 - 404
237
33 - 1681
69
2 - 387
81
2 - 450
30 - 34 9 (0) 124
57 - 236
98
48 - 199
132
60 - 250
139
63 - 263
4 (0) 238
65 - 610
300
83 - 1081
252
69 - 646
488
133 - 1251
35 + 10 (0) 247
119 - 455
222
113 - 436
205
99 - 378
340
163 - 626
         
ALL 71 (5) 112
88 - 142
115
90 - 147
127
99 - 161
134
104 - 169
22 (1) 119
75 - 180
121
78 - 187
123
77 - 187
121
76 - 184

1 number of ex-ONT cases in the brackets

Table 38
1964-89 Lung Cancer (ICD9 162) Risk Estimates and 95 % Confidence Intervals:
(r) INCO Iron Ore Recovery Plant (Never Sinter) by Duration of Exposure (15 years or more since first exposed)

  Iron Ore Recovery Plant hourly and foremen
DOE
[1]
OBS
[2]
SIR
[3]
CMF
[4]
PcMR
[5]
MOR
[6]
00 < 01 15 1(1) 128
72 - 211
111
55 - 222
134
75 - 221
160
90 - 264
01 < 02 1 (0) 29
1 - 164
22
3 - 159
60
2 - 335
54
1 - 299
02 - 04 4 (0) 105
29 - 270
161
39 - 655
116
32 - 296
114
31 - 292
05 - 09 6 (0) 232
85 - 505
176
75 - 412
155
57 - 337
182
67 - 397
10 - 14 1 (0) 30
1 - 167
36
5 - 252
24
1 - 134
22
1 - 123
15 - 19 3 (0) 110
23 - 322
88
26 - 301
74
15 - 215
91
19 - 267
20 - 24 1 (0) 56
1 - 312
27
4 - 188
70
2 - 388
47
1 - 264
25 + 1 (0) 129
3 - 721
109
15 - 772
58
2 - 322
52
1 - 291
ALL 32 (1) 106
73 - 150
101
51 - 201
100
69 - 142
106
72 - 149

1 number of ex-ONT cases in the brackets

Table 39
1964-89 Lung Cancer (ICD9 162) Risk Estimates and 95% Confidence Intervals:
(s) INCO Transportation & Maintenance Personnel (Never Sinter) by Duration of Exposure
(15 years or more since first exposed)

  All INCO Transportation & Maintenance: hourly and foremen INCO Mine Transportation & Maintenance: hourly and foremen
DOE
[1]
OBS
[2]
SIR
[3]
CMF
[4]
PcMR
[5]
MOR
[6]
OBS
[7]
SIR
[8]
CMF
[9]
PcMR
[10]
MOR
[11]
00 < 01 43 1(2) 95
68 - 127
103
70 - 150
121
88 - 164
126
91 - 170
18 1(0) 87
51 - 137
137
63 - 298
103
61 - 163
104
62 - 165
01 < 02 18 (0) 110
65 - 174
107
64 - 179
140
83 - 221
154
91 - 243
12 (0) 145
75 - 253
138
70 - 272
186
96 - 325
330
171 - 577
02 - 04 20 (0) 93
57 - 143
95
59 - 151
92
56 - 142
83
50 - 127
9 (0) 75
34 - 142
70
36 - 137
71
32 - 134
66
30 - 124
05 - 09 9 (1) 44
20 - 83
46
23 - 96
53
24 - 101
41
19 - 79
10 (1) 89
43 - 164
85
49 - 148
101
48 - 185
87
42 - 161
10 - 14 21 (1) 109
68 - 167
99
64 - 153
109
67 - 167
111
69 - 170
12 (0) 105
54 - 183
110
56 - 216
119
61 - 207
120
62 - 210
15 - 19 26 (2) 108
71 - 158
104
69 - 157
106
69 - 155
112
73 - 164
7 (0) 74
30 - 153
64
30 - 138
76
30 - 156
67
27 - 138
20 - 24 34 (0) 104
72 - 146
105
74 - 150
105
73 - 146
113
78 - 158
15 (0)
153
86 - 253
140
82 - 238
140
78 - 231
171
96 - 282
25 - 29 37 (1) 107
75 - 148
101
73 - 141
106
75 - 147
122
86 - 168
9 (0) 98
45 - 186
87
42 - 179
80
36 - 151
95
43 - 179
30 - 34 22 (0) 87
54 - 131
85
55 - 132
91
57 - 138
101
63 - 152
9 (0) 99
45 - 188
88
35 - 221
109
50 - 206
130
59 - 247
35 + 10 (0) 56
27 - 102
45
23 - 88
69
33 - 127
60
29 - 111
         
ALL 240 (7) 93
82 - 106
92
81 - 105
101
89 - 115
103
90 - 117
101 (1) 100
81 - 121
102
82 - 126
105
85 - 128
110
90 - 134

1 number of ex-ONT cases in the brackets


September 5, 1996

Mr. Glen Wright
Chairman
Workers' Compensation Board
200 Front Street West, 18th floor
Toronto, Ontario
M5V 3J1

Dear Mr. Wright,

I enclose a copy of the Panel's Report No. 12A, "Addendum to IDSP Report no. 12, Report to The Workers' Compensation Board on lung cancer in the Hardrock Mining Industry".

I would be pleased to discuss the Report with you. Please let me know when it would be convenient to do so.

Sincerely,


Nicolette Carlan
Chair


Endnotes

1. The SIR is the ratio of the observed number of site-specific cases of cancer which occurred in the cohort divided by the expected number of cases in the cohort (times 100).

2. In the McMaster report, both one-sided p-values and 95% confidence intervals were used. The one- sided p-value was used primarily as a screening tool to highlight the significant SIR estimates.

3. leaching, calcining and sintering

4. Tests for trend are carried out to see if the pattern of increasing risk parallels another variable, in this case, duration of exposure. Trends, like SIRs, can be either statistically or not-statistically significant.

5. INCO began operations in 1902 and Falconbridge in 1929, hence the Falconbridge tables by decade of first exposure start "pre-1940" rather than "pre-1930".

6. The exact number of personnel excluded was unobtainable. This is an approximate number based on available data and calculated by ODP staff.