You're right that no level of lead exposure is considered safe, but that doesn't mean that any lead exposure is going to have any kind of measurable effect on an organism.
Shouldn't the impact of leaded avgas be easier to measure, since the concentrations should be higher around airports which send up a lot of leaded avgas planes? It's a different situation than where every car was burning leaded gas and everyone was pretty much exposed to it. The effects should be much more localized and therefore easier to study.
The risk may be real, but it may be dwarfed by other sources of lead, making it a silly thing to worry yourself about. For example, you might get more lead into your body from 8oz of fruit juice than you would living a year near an airport.
Shouldn't the impact of leaded avgas be easier to measure, since the concentrations should be higher around airports which send up a lot of leaded avgas planes? It's a different situation than where every car was burning leaded gas and everyone was pretty much exposed to it. The effects should be much more localized and therefore easier to study.
The risk may be real, but it may be dwarfed by other sources of lead, making it a silly thing to worry yourself about. For example, you might get more lead into your body from 8oz of fruit juice than you would living a year near an airport.