[Radiation exposure and cancer mortality among nuclear power plant workers: a meta-analysis].
OBJECTIVE
We conducted a meta-analysis to investigate the relationship between low external doses of ionizing radiation exposure and the risk of cancer mortality among nuclear power plant workers.


METHODS
We searched MEDLINE using key words related to low dose and cancer risk. The selected articles were restricted to those written in English from 1990 to January 2009. We excluded those studies with no fit to the selection criteria and we included the cited references in published articles to minimize publication bias. Through this process, a total of 11 epidemiologic studies were finally included.


RESULTS
We found significant decreased deaths from all cancers (SMR = 0.75, 95% CI = 0.62 - 0.90), all cancers excluding leukemia, solid cancer, mouth and pharynx, esophagus, stomach, rectum, liver and gallbladder, pancreas, lung, prostate, lymphopoietic and hematopoitic cancer. The findings of this meta-analysis were similar with those of the 15 Country Collaborative Study conducted by the International Agency for Research on Cancer. A publication bias was found only for liver and gallbladder cancer (p = 0.015). Heterogeneity was observed for all cancers, all cancers excluding leukemia, solid cancer, esophagus, colon and lung cancer.


CONCLUSIONS
Our findings of low mortality for stomach, rectum, liver and gallbladder cancers may explained by the health worker effect. Yet further studies are needed to clarify the low SMR of cancers, for which there is no useful screening tool, in nuclear power plant workers.
Park
Eun Sook
ES
Radiation Health Research Institute, Korea Hydro & Nuclear Power Co., Ltd., Korea.
Moon
Kieun
K
Kim
Han Na
HN
Lee
Won Jin
WJ
Jin
Young-Woo
YW
D006801:Humans; D009381:Neoplasms, Radiation-Induced / Q000401:mortality*; D055848:Nuclear Power Plants; D009784:Occupational Diseases / Q000401:mortality*; D016273:Occupational Exposure / Q000009:adverse effects; D011834:Radiation Monitoring