Abstract
BACKGROUND AND AIM: Male hunters have slightly higher total cancer incidence versus male non-hunters in 9 Swedish counties after the Chernobyl Nuclear Power Plant (NPP) accident in 1986. The aim of this study was to investigate whether the contribution of absorbed dose from the Chernobyl fallout could have influenced the elevated cancer incidence, given that hunters have a higher internal radiation exposure due to consumption of game contaminated with ¹³⁷Cs. METHODS: An algorithm was developed to calculate the total absorbed colon dose as a sum of external and internal absorbed colon dose. The time-integrated total absorbed colon dose was calculated individually for hunters (n=40 874) 1986-2015. Allowing for a 5-year latency period, the age-adjusted Incidence Rate Ratios (IRR) per milliGray (mGy) with 95% Confidence Intervals (CI) were calculated using Poisson regression for the follow-up period 1991-2015. A total of 8 964 cancer cases occurred in the hunter cohort to 31 December 2015. Pre-Chernobyl total cancer incidence in each of the counties was investigated as a potential confounding factor. RESULTS:The mean colon dose was 2.39 mGy with more than half of the absorbed colon dose from internal ¹³⁴Cs and ¹³⁷Cs taken together. No specific cancer site showed a significant increased IRR per mGy. For total cancer the IRR per mGy was 0.995 (95% CI 0.988-1.003). The IRR did not change after adjustment for the pre-Chernobyl total cancer incidence. CONCLUSIONS:Using the total colon dose as proxy for the whole body dose, no dose-dependent increased risk for cancer was observed in hunters, hence the elevated cancer incidence in hunters versus non-hunters could probably not be attributed to intake of ¹³⁷Cs contaminated game after the Chernobyl NPP accident. Future analyses will calculate individual organ absorbed dose and investigate dose-response relationship for those cancer sites. KEYWORDS: incidence, ionizing radiation, environmental epidemiology, exposure assessment, cancer and cancer precursors
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call