It seems bonkers, but much older diesels are, in a way, cleaner than modern diesels.The current 'cleaner' diesels use technology to omit and trap particulates and these get separated in the process. But the final emissions ( what comes out of the exhaust ) is now more of a vapour of very fine microscopic particles compared to what you could describe as 'soot' from older diesels.These fine emissions are so microscopic that that are easier to inhale but can also be absorbed by the skin. And some of the toxins are now released that previously were encapsulated by the larger particulates.With older diesels, the particulates were much larger, so visibly more evident generally too large to be absorbed by us. The soot would be visible and washed off or by blowing one's nose etc. That does not mean that it does not have an effect. Just like hayfever from pollen, some will get a reaction. But because the emissions were so heavy, the deposits would fall to the ground and generally wash away and break down naturally.The real problem began when additives started to be put into Derv. which at the time, was also being similarly added to petrol to try and maximise miles per gallon and minimise engine wear.Then diesels became hugely economic and efficient for consumption and some improvements like particulate collectors improved emissions. But the more recent developments have had the unfortunate effect of creating newer, less containable hazards.So the traditional Dirty Diesel, is cleaner than a Clean diesel.The challenge for engineers is to have a real low emission diesel that remains efficient and contains the microbes of toxins. But given the toxins emitted from buildings, hi rise in particular, it is really only HGVs and Taxis and Buses that cause any great amount of taxic pollution.But Hybrid and Electric buses are barely being included in tender renewals on routes of high density traffic other than in Central London. There are just a handful in operation around Ealing and Hounslow and no all electric or hydrogen buses and yet we are told this is the most polluted area. No controls on hi- rise building emissions, and nothing on public transport of any substance.Oxford Street is still being held up as a dangerously polluted area and yet almost every bus operating along this street is either Hybrid or Battery/Electric or Low Emmission and it seems to escaped the notice of campaigners but it has also been banned to private cars for over 30 years. It's only Taxis and delivery vehicles.This ought to be any starting point.But as the BBC report exposes. it's not really about pollution. It's about money, power and egos.
Mark Kehoe ● 3330d