I'll confess that my opening post was a bit more aggressive than necessary. Over the last few months I'd read and heard the statistics about the frightening number of deaths every year resulting from NOx and those statistics alarmed me so much that I didn't phrase my concerns as sensitively as I should have. I apologise because I did not intend to imply that diesel owners were "stupid, ignorant, bad people". But on rereading it, I can understand why some members will have thought that. Again, I'm sorry.
However, just as I said I didn't then understand why diesel purchasers apparently ignored the statistics, neither do I understand the extent of grossly negative and insulting responses. I had a few people who gave very good reasons for not considering the emissions as part of their purchasing decisions, mainly because they'd been misled by government and manufacturers or they hadn't heard about the issues. That's all I needed to answer my initial question and I would probably have left it at that. But all the denials without a thread of evidence to back them up, combined with the unnecessary personal attacks, left me with no option other than to respond. Surely one of the purposes of this forum is to discuss motoring matters. It's not much of a discussion when one side can only say "you're wrong" or "you need to get rid of your car".