title: Cancer risks and low-level radiation in U.S. shipyard workers.
abstract: The risks for four cancers, leukemia, lymphopoietic cancers (LHC), lung cancer and mesothelioma, were studied in workers from shipyards involved in nuclear powered ship overhauls. The population represented a sample of all workers based on radiation dose at study termination. The final sample included 28,000 workers with > or = 5.0 mSv, 10,462 workers with < 5.0 mSv and 33,353 non-nuclear workers. Nuclear workers had lower mortality rates for leukemia and LHC than US white males but higher rates of lung cancer and a significant five-fold excess of mesothelioma. Dose-dependent analyses of risks in the high exposure group indicated that for each cancer the risk increased at exposures above 10.0 mSv. An internal comparison of workers with 50.0 mSv exposures to workers with exposures of 5.0-9.9 mSv indicated relative risks for leukemia of 2.41 (95% CI: 0.5, 23.8), for LHC, 2.94 (95% CI: 1.0,12.0), for lung cancer, 1.26 (95% CI: 0.9, 1.9) and for mesothelioma, 1.61 (95% CI: 0.4, 9.7) for the higher exposure group. Except for LHC, these risks are not significant. However, the increasing risk with increasing exposure for these cancers, some of which are known to be related to radiation, suggests that low-level protracted exposures to gamma rays may be associated with these cancers. Other agents such as asbestos, which are common to shipyard work, may play a role especially in the risk of mesothelioma. Future follow up of the population would identify bounds on radiation risks for this population for comparison with similar risks estimated from other populations.
authors: Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, MD 21202-6709, USA. gmatanos@jhsph.edu
authors: Genevieve M
authors: GM
authors: Matanoski
authors: James A
authors: JA
authors: Tonascia
authors: Adolfo
authors: A
authors: Correa-Villaseñor
authors: Katherine C
authors: KC
authors: Yates
authors: Nancy
authors: N
authors: Fink
authors: Elizabeth
authors: E
authors: Elliott
authors: Bruce
authors: B
authors: Sanders
authors: Deborah
authors: D
authors: Lantry
mesh_terms: D000328:Adult; D004307:Dose-Response Relationship, Radiation; D005500:Follow-Up Studies; D005720:Gamma Rays / Q000009:adverse effects*; D006801:Humans; D007221:Industry / Q000706:statistics & numerical data; D008297:Male; D009369:Neoplasms / Q000209:etiology* / Q000401:mortality*; D009381:Neoplasms, Radiation-Induced / Q000401:mortality*; D009688:Nuclear Reactors / Q000706:statistics & numerical data; D016273:Occupational Exposure / Q000009:adverse effects* / Q000706:statistics & numerical data; D018570:Risk Assessment; D012307:Risk Factors; D013995:Time; D014481:United States