This picture was taken after a normal race night 100 yards from the race track. In 2008 they covered the track with sifted clay that is finer than asbestos. Dust that is so fine it can't be kept out of homes."If you can't breath, nothing else matters."
Some of the cars probably have more than 1000 hp. And with wings the dust is forced hundreds of feet into the air. Dust to normal air stagnation the fine, almost gas dust if it is suspended in the air.
One call to the DEP should have solved the problem. One of my friends was special guest at one of the races they had at the track. He died that night. He had terminal cancer and should not have been there.