ElM, the particulates are not benign. Concawe studied the goop coming out of diesel engines and as with all burning or heavy organic detritus, there are all sorts of evil carcinogens produced.
LPG burns cleanly and so do good quality petrols with no aromatics. Some diesels burn reasonably cleanly, especially in a lean burn environment. But diesels with heavy ends gooping them up will not burn cleanly, leaving sticky, oily, black particles of DNA mutater and building blackener. London used to be thick with it.
People thought London was clean in the 1980s only because many people remembered the 1950s, but it was disgusting. The end of a day would see nose full of black muck, corners of eyes, washing a shirt after a day made the water darken. Going for a run in the evening [when people turned on their fires to add to the miasma] was nasty - I'd give up after a couple of hundred meters and go home.
1 nitro pyrene was just one of the evil carcinogens produced from diesel engines.
On my training course with Texaco in Toronto in 1975, I recall Eric Glew, the boss, explaining that diesel engines were clean. I wondered what the heck he meant as diesel engines to me were black smoke belching evil oilers. What he meant was in the pedantic sense of carbon monoxide emissions, the pollutant of concern at the time, they are low in emissions. Which is true. That might be why Los Angeles stayed filthy for so long - catalytic converters were cutting CO but diesel engines allowed to just carry on.
Mqurice |
