I have been learning a little about the health effects of gasoline lately, and it is not good news.
One report here discusses the dangers of ethanol. Aside from all the other issues with using ethanol as a fuel, this one sounds like a pretty nasty mew problem if ethanol becomes a popular additive.
Speaking of fuel additives, I recently also discovered the frightening story of MMT, the gasoline additive using manganese, a human neurotoxin known to cause serious illness. Brought to the world by Ethyl Corp, the company that also brought leaded-petrol (tetra-ethyl lead) to the world, and which obviously losing customers on that product, this lovely company recently leveraged the terms of the free trade agreement NAFTA to force Canada to lift its ban on MMT, despite serious concerns in that country that airborne manganese causes disabling neurological impairments in movement and speech.
It looks like car exhaust really is as nasty as it smells - that is unless of course you drive a hydrogen powered Humvee like Arnie...