This is the best part.
"The biggest source of soot in developed countries is diesel fuel, but major sources elsewhere include burning wood, animal dung, vegetable oil and other biofuels. "
Every summer the skies over Texas get covered with smoke from Mexico. Like this has anything to do with Diesels, but the Diesel is an easy target.
Course if you add in the smoke from this summers wildfires in California due to the tree huggers wacko environmental stance, you would see that environmentalists are contributing to the problem more so than diesels thanks to bigger wildfires.