It's unlikely to have been a direct cause given the (relatively) low levels of lead avgas generates, but it almost certainly has some effect. The question is,

It's unlikely to have been a direct cause given the (relatively) low levels of lead avgas generates, but it almost certainly has some effect. The question is, given that it's so clearly a poison (maybe a top 10 poison) - why spray it into the air above residential neighborhood? Lead impacts are around things like "anaemia, hypertension, renal impairment, immunotoxicity and toxicity to the reproductive organs. The neurological and behavioural effects of lead are believed to be irreversible." Reality is measurable increases in lead concentrations in blood near airports is very small. But does look like it exists.