Protocol for a further study of cancer among the current and former employees of National Semiconductor

This document is a study protocol for the further investigations that HSE wishes to undertake into the risks of cancer among workers and ex-workers of the National Semiconductor UK (NSUK) plant at Greenock in Scotland. It sets out what follow-up investigations we plan to do and how we intend to do them, including how we intend to report the findings. The new investigations follow on from an earlier HSE study of the occurrence of cancer in a cohort study group of 4388 workers and ex-workers at the NSUK plant. That study found some evidence that, in women, cancers of the lung and stomach were occurring more frequently than would be expected in the general population, after taking account of the social and economic factors associated with postcode of residence. There was also some suggestion of excess breast cancer in women and brain cancer in men. The present revised protocol follows on also from an extensive consultation carried out by HSE on an earlier draft. That consultation included the independent Study Steering Committee (SSC), National Semiconductor and its scientific advisors, the NSUK workforce and Phase Two (Appendix 1). In the light of that consultation, and of concurrent developments in other studies, the present revised protocol describes linked studies of a simpler design than originally proposed. However, the main purpose (aim) of the further investigations remains unchanged; it is to help clarify whether the rates of any of these cancers in the NSUK workforce might be related to work done there. As well as studying work done at NSUK, we will need to take into account work done elsewhere, and non-work factors, to the extent that these are important risk factors for the cancers of main interest in this further study.