While I agree that the amount of lead from an average NASCAR race wouldn't have any effect on the environment or on fans, much of the columns arguments for continuing to use leaded fuel are specious.
"Leaded race fuel is less likely to explode."- BS. The 110 octane fuel used by NASCAR is just as flammable as what you or I put in our cars.
"It makes the cars run better."-Also BS, the manufacturers could easily make the changes required to run unleaded fuel, without hurting performance at all. They re-design their engines every year anyways, so the change wouldn't hurt the sport.
The only reason that NASCAR still uses leaded gas is that leading is a cheaper way of raising octane tha the chemicl additives that civilian fuel uses. Changing to unleaded might cost them as much as $1000 a race. Whoopy.
As for aviation engines, the government didn't force the change to unleaded aviation fuel because then they would have had to change all the piston engine aircraft over to unleaded, at extraordinary expense. They could have, however, simply required that all new aircraft be compatible with unleaded fuel.
All of this is from the horse'* mouth, my Father. He'* been with the EPA for 27 years.
And, no, I ain't no damn tree-hugger, I'm as big a NASCAR fan as any avowed redneck.