Correction of AECL doses in the NDR, and Mortality and Cancer Incidence Analysis of Canadian NEWs

The over-arching objectives are to validate that the National Dose Registry (NDR) database contains all the best available data for Atomic Energy of Canada Limited (AECL) workers, and then to use the whole NDR dataset, linked to mortality (1950–2018) and cancer incidence (1969–2018), to characterize the dose-response relationship between occupational exposure to ionizing radiation and health outcomes. The contractor will:

a. Review and compare the characteristics and doses of the different AECL source files to the NDR. Identify all discrepancies and recommend and document corrective measures. Review and describe characteristics of AECL links and non-links to the NDR. Create a corrected AECL file, through discussions with HC and the Canadian Nuclear Safety Commission (CNSC).

b. Replicate and compare an analysis published by AECL in 1993 (Gribbin, Weeks et al. 1993) using the corrected AECL file and mortality follow-up to 1990. Compare risk estimates with the Gribbin study and assess the impact of the dose corrections on risk estimates and the impact of links/non-links to the NDR.

c. Meet with CNSC and HC staff to discuss the dose discrepancies and seek consensus on any recommended additions/corrections to doses to the NDR. HC will make the agreed additions/corrections in the NDR.

d. Prepare a report, which includes the background, methods, results, discussion, conclusions, and recommendations of the verification and correction of AECL doses (a.), dose-response analysis (b.) and addition of early AECL doses in the NDR (c.). The report will be internally and externally peer reviewed. HC and CNSC staff will arrange the peer reviews and contractor will prepare disposition report in response to peer reviewers.

In partnership with Health Canada (HC) and the Canadian Nuclear Safety Commission (CNSC), the contractor will also:

e. Prepare a scientific proposal for an updated mortality (1950–2018) and cancer incidence (1969–2018) analysis of the NDR’s Canadian nuclear energy workers (i.e., background, objectives, proposed analysis strategy, proposed methods, timetable, deliverables, and budget).

f. Participate in activities (i.e., prepare applications, support presentations, revise proposal) to obtain approvals (i.e., PHAC/HC Research Ethics Board approval, Statistics Canada Microdata Access Agreement) for this project.

g. Conduct a detailed statistical analysis as outlined in the scientific proposal. This must include the following:

1. Comparison of the rates of all causes of mortality and all causes of cancer incidence of the cohort with those for the sex- age- and calendar-specific rates for the general Canadian population (SMR and SIR).

h. Detailed internal scientific analysis of the cancer mortality (1950–2018) and cancer incidence (1969–2018) among the NDR’s Canadian nuclear energy workers cohort with respect to the following:

1. Whole-body doses of low-LET ionizing radiation (internal comparisons, dose response relationships, modifying effects, confounding, etc.).
2. Internal doses from tritium (internal comparisons, dose response relationships, modifying effects, confounding, etc.).

i. Prepare a detailed draft report (introduction, methods, results, discussion, and conclusion) for external peer review. HC/CNSC staff will arrange the external peer review.

j. Prepare a final report, which dispositions/addresses the peer review comments.

k. Prepare manuscript (in partnership with HC/CNSC staff) for publication.