(a) Study and analysis
(1) The Administrator shall conduct a study concerning the effects on health and welfare of particulate emissions from motor vehicles or motor vehicle engines to which section
7521 of this title applies. Such study shall characterize and quantify such emissions and analyze the relationship of such emissions to various fuels and fuel additives.
(2) The study shall also include an analysis of particulate emissions from mobile sources which are not related to engine emissions (including, but not limited to tire debris, and asbestos from brake lining).