Hi Jim,
Note that lead is very heavy compared to water. (water is why you may be thinking a gram is a milliliter). 1.6 grams of lead per gallon is one milliliter, and a typical additization rate for 100LL... 2 grams/gallon is the maximum per the 100LL specification.
Yes, lead metal is about 11.5 times as heavy as water, but tetraethyl lead is about 1.7 times as heavy as water, quite a difference.
I think you pretty much have to take a bath in lead to raise your cancer risk... the most concerning risk is that very small doses of lead has a negative impact on brain and nervous system function, and those can be life long effects for those exposed as infants or children... There's no safe dose of lead with respect to neurotoxicity. Animal studies show that it takes substantial lead exposure to induce cancer.
And there are studies that show the exact opposite. My bag isn't medicine, but I can read reputable reports that disagree with one another and opt not to take a bath in lead since to be liquid it will have to be around 400-450 °F. I can't take a side as I know nothing about neuroscience or oncology.
That's why a number of us are working very hard to bring unleaded avgas to market that performs as well as 100LL, or performs better in some respects. The FAA is working hard too, but they're sometimes misguided (bad science). The FAA has never approved a fuel before, they only approve engines and airframes to operate on ASTM specified fuels. So the FAA doesn't have much bench strength in that arena.
They can lift my ticket tomorrow for maintenance malpractice and we've been dicking around for twenty years trying to get 94UL or 100UL to market. Then again, politicians aren't all that jacked up to put the screws to the ethanolmogas market since the first primary of the political race is in Iowa, which just HAPPENS to be totally invested in corn production for alcohol.
Politics is a bipartisan word .... Poly is the Greek for "Many" and Ticks are just bloodsucking parasites.
jw.
Paul
