[Blackbirdws6]

Most people won't know the science of what you are referring to. As Bill mentioned, the visable smoke and soot is going to get more attention than invisible but very harmful alternatives. On somewhat a tangent, when I visited California, I was amazed at the smog level compared to NJ. It is no wonder they are the most forward thinking with regards to energy efficiency in the country. When its blatantly staring you in the face (similar to rolling coal), sensitivity skyrockets and actions are taken.

Focusing more on removing the irresponsible tuning group would be the ideal solution however the enforcement would be more time consuming and expensive. It's easier for them to ban the whole lot than to help the group mature.