This study uses record linkage between the National Registry of Childhood Tumours (NRCT) and the National Registry for Radiation Workers to re-assess our earlier finding that the offspring of women radiation workers exposed to ionising radiation before the child's conception may be at an increased risk of childhood cancer. An additional 16 964 childhood cancer patients taken from the NRCT, together with the same number of matched controls, are included. Pooled analyses, based on the new and original datasets, include 52 612 cases and their matched controls. Relative risks (RRs) for maternal employment as a radiation worker, maternal exposure or not during the relevant pregnancy and pattern of employment relative to conception and diagnosis dates were calculated.The new data provide no evidence of an increased risk of childhood cancer associated with maternal preconception radiation work and thus do not support our earlier finding of a raised risk in the offspring of female radiation workers. Considering the pooled data, a weak association was found between maternal radiation work during pregnancy and childhood cancer in offspring although the evidence is limited by the small numbers of linked cases and controls.
Bibliographical noteFunding Information:
We acknowledge the help of colleagues at CCRG and HPA, and all who have contributed data to this study; further details of contributing organisations can be found in the HPA report (Muirhead et al, 2009). The work of the CCRG is supported by the Department of Health for England and Wales and the Scottish Ministers. Specific funding for this study was received from the Department of Health’s Radiation Protection Research Programme. This study received ethical approval from Trent Multi-Centre Research Ethics Committee (MREC/02/4/048) and the Epidemiology and Registry Group of the Children’s Cancer and Leukaemia Group.
- Childhood cancer
- In utero exposure
- Ionising radiation
- Occupational exposure
- Preconception irradiation