Smaller airports are a bigger problem than large ones: https://www.politico.com/news/2023/02/20/aviation-lead-fuel-00081641

I live near an airport (specifically under the path that most planes take when departing) and I don't have kids but there's an elementary school near my house that dozens of small airplanes fly over every day. I've had the soil around my house tested and it has slightly elevated levels of lead but still under the EPA's "safe" limit.