The Onion could have fun with this. The NRDC director of NRDC’s Southern California air program, David Pettit, recently argued in Federal court that diesel exhaust particulate matter is a solid, and the court concluded that it is not.
Source: What’s in Diesel Exhaust, Michigan Diesel Cleanup Campaign
The case is, of course, much more complex. A summary from the excellent Courthouse News Service is below, and the applicable court document is here.
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