摘要：Ba c k g r o u n d: Risks of most types of leuke mia from exposure to acute high doses of ionizing radiation are well known, but risks associated with protracted exposures, as well as associations between radia-tion and chronic lymphocytic leuke mia (CLL), are not clear.oB j e c t i v e s: We estimated relative risks of CLL and non-CLL from protracted exposures to low-dose ionizing radiation.Me t h o d s: A nested case–control study was conducted in a cohort of 110,645 Ukrainian cleanup workers of the 1986 Chornobyl nuclear power plant accident. Cases of incident leuke mia diagnosed in 1986–2006 were confirmed by a panel of expert hematologists/hematopathologists. Controls were matched to cases on place of resi dence and year of birth. We estimated individual bone marrow radia-tion doses by the Realistic Analytical Dose Reconstruction with Uncertainty Estimation (RADRUE) method. We then used a conditional logistic regression model to estimate excess relative risk of leuke-mia per gray (ERR/Gy) of radiation dose.re s u l t s: We found a significant linear dose response for all leuke mia [137 cases, ERR/Gy = 1.26 (95% CI: 0.03, 3.58]. There were nonsignificant positive dose responses for both CLL and non-CLL (ERR/Gy = 0.76 and 1.87, respectively). In our primary analy sis excluding 20 cases with direct in-person interviews < 2 years from start of chemo therapy with an anomalous finding of ERR/Gy = –0.47 (95% CI: < –0.47, 1.02), the ERR/Gy for the remaining 117 cases was 2.38 (95% CI: 0.49, 5.87). For CLL, the ERR/Gy was 2.58 (95% CI: 0.02, 8.43), and for non-CLL, ERR/Gy was 2.21 (95% CI: 0.05, 7.61). Altogether, 16% of leuke mia cases (18% of CLL, 15% of non-CLL) were attributed to radiation exposure.co n c l u s i o n s: Exposure to low doses and to low dose-rates of radiation from post-Chornobyl cleanup work was associated with a significant increase in risk of leuke mia, which was statistically consistent with estimates for the Japanese atomic bomb survivors. Based on the primary analy sis, we conclude that CLL and non-CLL are both radiosensitive
