Paternal preconceptional irradiation, population mixing and solid tumors in the children of radiation workers (England)

Objective: To investigate whether there was an increased incidence of solid tumors among offspring of male radiation workers at the Sellafield nuclear installation in Cumbria, northwest England and whether paternal preconceptional irradiation was associated with the risk of solid tumors. Methods: A cohort study of 266,710 live births in Cumbria, 1950-1991, followed up to age 25 years on the end of 1991. Results: Children of radiation workers had a non-significantly increased risk of solid tumors (RR = 1.5, 95% CI: 0.9-2.4, p = 0.09), determined largely by an increased risk of cancers excluding leukemias, lymphomas, brain, spinal and gender-specific tumors (RR = 1.9, 95% CI: 1.0-3.3, p = 0.05), which was partly explained by differing patterns of parental migration (adjusted RR = 1.7 95% CI: 0.8-3.2, p = 0.50). Within children of radiation workers there was no evidence of an increased risk with increasing paternal preconception dose of external radiation (hazard ratio per 100 mSv for all solid tumors = 0.61, 95% CI: 0.1-1.8, p = 0.52). Conclusions: Any observed excess of solid tumors in children of radiation workers may be partly explained by population mixing. Fathers' occupational exposure to radiation before conception was not found to be risk factor for solid tumors in their children.