Occupational Radiation Exposure and Leukemia Mortality among Nuclear Workers in Japan: J-EPISODE, 1991-2010

Abstract

Whether exposure to radiation at low dose and at low dose rate is related to leukemia mortality and morbidity remains controversial. Cohort studies of nuclear workers chronically exposed to radiation at low dose and at low dose rate in their come mostly from Western countries, with few from Asian countries. The present study aimed to examine radiation's effects on mortality from leukemia, in a cohort of Japanese nuclear workers. The cohort consisted of 204,103 workers, who were followed from 1991 to 2010, with a total of 2.89 million person-years. The mean age and mean cumulative dose at the age at the end of follow-up were 55.6 years and 13.8 mSv. During the study, 209 leukemia deaths were observed. The linear excess-mortality was not observed in this study of Japanese nuclear workers. The cohort, however, is still young. Further followup is needed to obtain more reliable estimates of leukemia risks for Japanese workers exposed to low dose and low-dose rate radiation.

Conversion Factor From Dosemeter Reading to Air Kerma for Nuclear Worker Using Anthropomorphic Phantom for Further Conversion From Air Kerma to Organ-Absorbed Dose

“…The Japanese Epidemiological Study on Low-Dose Radiation Effects (J-EPISODE) ( 1 ) has been conducted since 1990 and has analyzed the health effects associated with radiation exposure evaluated as the personal dose equivalent, H p (10). However, the evaluation of cancer morbidity and mortality using the organ-absorbed dose (Gy) is recommended by the International Commission on Radiological Protection (ICRP) ( 2 ) , and it was adopted for the 15-Country Collaborative Study of cancer risk among radiation workers in the nuclear industry conducted by IARC ( 3–5 ) , the International Nuclear Workers Study (INWORKS) ( 6–9 ) , Mayak study ( 10 ) and the Life Span Study of atomic bomb survivors ( 11–13 ) .…”

A Risk Comparison of Non-cancer Mortality between Lifestyle, Socioeconomic Status, and Radiation among Japanese Nuclear Workers (J-EPISODE)

“…where l is the death rate and l 0 is the background death rate [stratified by a: 5-y attained age categories (20-, 25-, ... and 100+)]; r = residence, which is divided into eight regional categories within Japan (Kudo et al 2018a(Kudo et al and 2018b(Kudo et al , 2022; and z 1 -z 11 represent the variables used to estimate RRs. More specifically, z 1 was smoking (pack-y), z 2 was alcohol consumption (ethanol in grams per day), z 3 was health consciousness, z 4 was frequency of medical examination, z 5 was breakfast intake, z 6 was sleep, z 7 was BMI, z 8 was job category, z 9 was job position, z 10 was years of education, and z 11 was the cumulative radiation dose, assuming a 10-y lag.…”

A Risk Comparison between Lifestyle, Socioeconomic Status, and Radiation: A Cohort Study of Cancer Mortality among Japanese Nuclear Workers (J-EPISODE)

“…The health effects of high-dose radiation were made visible by studies on atomic bomb survivors ( Pierce et al 1996 ; Preston et al 2003 ; Ozasa et al 2012 ). While several studies have been carried out ( Kudo et al 2018a and b ; Haylock et al 2018 ; Leuraud et al 2015 ; Richardson et al 2015 ), consensus on the health effects of low-dose radiation has not been established. This suggests that if they exist, these effects are difficult to detect because they are probably less than the risks due to lifestyle or socioeconomic status.…”