Table 5. Modification of radiation-related risks of mortality from solid cancer by start of nuclear monitoring in the revised cohort of Canadian nuclear workers, 1956–1994.
| N subjects/PY | N deaths | Mean dose (SD), mSv | ERR/Sv (95% CI)a,b | P-valuec | |
|---|---|---|---|---|---|
|
Risks by facility and by start of first monitoring | |||||
|
AECL |
15 937/298 462 |
208 |
20.29 (47.83) |
3.25 (0.11, 8.85) |
0.04 |
| First monitored 1956–1959 | 1355/46 016 | 74 | 37.04 (71.19) | 7.78 (1.52, 21.5) | <0.01 |
| First monitored 1960–1964 | 1733/52 899 | 39 | 20.15 (46.06) | 3.75 (<−2.02, 70.3) | 0.81 |
| First monitored 1965–1994 |
12 849/199 547 |
95 |
13.61 (32.72) |
−1.03 (<−1.66, 5.76) |
0.63 |
|
Hydro-Québec, New Brunswick Power Corporation, Ontario Hydrod |
27 926/287 338 |
212 |
19.47 (41.02) |
−0.32 (<−1.90, 8.20) |
0.91 |
| First monitored 1965–1994 | 27 907/286 771 | 212 | 19.56 (41.20) | −0.68 (<−1.91, 7.45) | 0.81 |
Abbreviations: AECL=Atomic Energy of Canada Limited; CI=confidence interval; ERR/Sv=excess relative risk per sievert; mSv=milliesievert; PY=person-years; SD=standard deviation.
a
Models adjusted for sex, attained age, socioeconomic status (SES), calendar time and duration of monitoring by stratification.
b
Doses lagged by 10 years.
c
P-value from the likelihood ratio test for departure of ERR/Sv from zero.
d
Does not include 1453 nuclear workers (17 solid cancers) who were monitored in multiple facilities, because most of them were monitored at AECL after 1965.