In this economic climate where we are encouraged to minimise our collective waste and stifle the pressures on manufacturing products which are polluting our environment, those developing the “AdBlue” technology deserve high praise. (A trucking big relief for us all, 21/12). The adaptation of a bodily human by-product (urea) to neutralise the polluting nitrogen oxides from the diesel engines works well. With human urine constituting 5 per cent urea, I expect the next clever innovation will be setting up recycling units at our pubs and clubs. Not only will we keep our wonderful truckies on the road, we will be supporting our clubs and pubs in their post-Covid recovery. Alan Sexton, North Parramatta 22Dec2021.