Mexicans who have no Indian blood would still be classified as Hispanic, a race classification that is not genetically determined. Be careful though, lumping all Native Americans is one huge group is not being very respectful of them.
Lead wheel weights have been banned in the EU since July 2005, and Japan and Korea are phasing them out. Yet EPA has refused to enact a ban, instead relying on voluntary industry action.
The ban on leaded gasoline led to thousands of tons of lead not being released in the air by automobiles. Similar bans in other countries have resulted in lowering levels of lead in people's bloodstreams. A side effect of the lead additives was protection of the valve seats from erosion.