Re: Response to letter by Dr Busby about our article ‘Mortality and cancer incidence 1952–2017 in United Kingdom participants in the United Kingdom’s atmospheric nuclear weapon tests and experimental programmes’

Dear Editor, We are grateful Dr Busby has shown such interest in our paper on the mortality and cancer incidence experience of the UK atmospheric nuclear test participants [1]. He asks several questions about the study and its findings some of which we feel warrant a reply and these are detailed below. Firstly, he expresses surprise Dr Haylock gave no conflict-of-interest statement in the paper as he was called to give evidence as an expert witness by the Secretary of State for Defence at a tribunal 2016 involving some of the test participants. Dr Haylock is employed by the UK Health Security Agency (UKHSA), an executive agency of the Department of Health and Social Care. One of the purposes this agency is to provide impartial advice to government agencies and other organisations on radiological hazards. It was in this capacity and because of his expert knowledge on the UK test participant studies that he was asked to give his impartial evidence at this tribunal. Dr Haylock certainly received no personal benefit from his involvement in this tribunal and we do not believe any conflict-of-interest statement was therefore necessary. The fourth analysis of UK test participants [1] was published over 5 years after the Tribunal hearings to which Dr Busby refers were concluded. No material from this analysis played any part in the tribunal hearings. The Ministry of Defence (MoD) has from its inception funded the long-term maintenance of the Nuclear Weapon’s Test Veterans study and each of the analyses. However, the study has been controlled and managed completely independent of the MoD firstly by the National Radiological Protection Board for many years and now latterly by the UKHSA. The MoD has had no influence on the analyses we have published and has no input into the study findings which are entirely based on our own impartial assessments. Given the extremely long-term nature of this study, now over 40 years, we believe that government funding is the only way that such a study can be maintained for such a long period. Dr Busby then goes on to question the selection of cancer sites included in the main paper and implies that this may have been in some fashion influenced by Dr Haylock’s involvement in the 2016 tribunal. This is an invalid argument given that that pancreatic cancer results are included in the supplementary material as he himself acknowledges. The reality is that over 90 cancer and non-cancer disease endpoints were defined prior to the start of the analysis, and these are detailed in the supplementary tables accompanying the paper (tables S20c and S20d). This includes a complete range of cancer and non-cancer outcomes including pancreatic cancer. When studying this many disease endpoints, a selection process around what results to