Yes, but the avgas lead situation is primarily a problem for the people behind/under the aircraft, not inside the aircraft.
Naively (without looking at data for concentrations in various environments), I could buy that people regularly handling / being around leaded aviation fuel are worse off than those breathing the (dilute) exhaust products.
:)
But for planes, normal age more than 20 years, even exist workhorses with 70 years.
They have very old engine technologies, some literally spread gas on ground (use lead in it to lubricate valves, which are outside, like on old star engines). So even when you walking where such plane was, you will gather some lead.