Until we can be satisfied that the UK has undertaken a proper study on this topic to establish whether there is a risk or not (cf Australia), and with acknowledgement to Upton Sinclair, I think the only way forward is to press for ALL aircrew to formally and properly report ANY suspected air contamination. The method of so doing needs to be properly established and I would have expected the multiple pilot and cabin crew unions to lead the way here. I would suggest that any 'odours' are relevant since their presence indicates the existence of some contaminant.
I can see nothing obvious on the IPA website and CHIRP appears to have no item since 2008. If BALPA appear to be exercising 'Nelson's eye' here (members need to ask!!), then we should press the cabin crew unions to agitate since it is their health that may well be in danger as well.