Pre-conceptional radiation exposure and transgenerational effects

Abstract

Between 1952 and 1958 the British Government carried out multiple nuclear bomb tests in Australia and South Pacific, causing radioactive material to be released into the atmosphere and surrounding areas. During the 1970’s health issues were raised by the veterans and their descendants, of which a number believe was due to their participation at the nuclear test sites. Whether the phenomenon of transgenerational effects occur due to exposure to ionising radiation in humans remains uncertain, although evidence has been presented for this in experimental models. This has led to some members of the veteran community to be anxious regarding their health and that of their children. Initially, a systematic review was conducted to assess the published evidence for health outcomes in offspring of exposed parents. Based on analysis of 158 peer-reviewed studies, there is no evidence to suggest increases in solid cancer rates amongst offspring of exposed (or suspected) individuals, however, there is limited evidence to suggest a possible increase in non-solid cancers. Non-cancer related diseases and mortality studies all detected no effect. Moderate evidence for an effect was seen for increased mutation rates amongst offspring of occupationally exposed cohorts and a meta-analysis showed an increase in congenital abnormalities in unexposed offspring born to exposed parents, although limited by low sample size and heterogeneity. Environmental studies showed high heterogeneity between studies and uncertainty around timing of exposure. Blood samples from the British Nuclear Test Veterans’ offspring and controls were collected for cytogenetic analysis. No evidence of any constitutional abnormalities was found in nuclear test offspring, except one veteran and child were identified as having the same Robertsonian translocation. A separate technique for analysis of non-clonal chromosome aberrations also showed no difference between the test and control samples. However, limited associations were observed between the test veterans offspring’s chromosomal aberrations and the veteran fathers total chromosomal damage burden and, complex chromosome aberration frequencies. No associations were observed in the control group. A higher number of recruited test veteran families reported a congenital abnormality when compared to control families. However, these results should be interpreted with caution due to possible selection bias and limitations of the study carried out including sample size and lack of dosimetry information.