Re: [MBZ] From Greenwire -- AIR POLLUTION: EPA issues guidance fordiesel engine NOx controls

[Peter Frederick]

It causes smog -- that nasty soup of chemicals produced by the 
oxidation of unburned hydrocarbons by ozone.  Some of this stuff (if 
not all), collects as water based microdroplets, and can also then dry 
into particulate matter.  Add in the soot from diesels and the dust 
from gassers, fly ash from un-treated power plants (nearly all of them, 
by the way), and you have some really horrible stuff that is fully 
"breathable" -- fine enough to go right past all your lung defenses 
into the bronchia and air sacs.

Peter