There are two major kinds of airplane fuel: jet fuel, and avgas.

Avgas has lead in it. It is used by piston engine airplanes. Little trainer planes. Cessnas and so on. There aren’t so many of them and they’re small so overall they don’t use enough fuel to make a huge difference to your health.

Jet fuel is basically like kerosene or diesel fuel. It is not leaded. It’s not exactly nontoxic but no, that big ass jet is not spewing tons of lead behind it.