I'm worried about emissions from the aircraft, which I am guessing will probably be gas powered. Airplane emissions are not as tightly regulated as automobiles. In fact, airplanes are allowed to use leaded fuel [1]. Now imagine a fleet of uber planes flying around constantly over your city.
Leaded avgas is going away, although slowly. No one is developing new piston engines or complete aircraft that use it. Any liquid fuels for new aircraft are going to be unleaded gasoline or (more likely) kerosene.
1. https://www.scientificamerican.com/article/lead-in-aviation-...