impact on health of 10% reduction in gas use

http://newscenter.lbl.gov/feature-stories/2009/05/27/biofuels-and-human-health/

Nonetheless, McKone and Lobscheid were able to prepare an LCIA for reduced gasoline use based on the damage to human health that emissions from gasoline burning can cause. For a baseline, they used a 10-percent reduction in gasoline use. In assessing the impact of these emissions on human health they looked at “disability adjusted life years or “DALYs,” which is a combination of two common damage factors in LCIAs - years of life lost due to premature mortality (YLLs) and the equivalent years of life lost due to disability (YLDs). One DALY is equal to one lost year of “healthy” life. To put this into perspective, the total annual disease burden in the United States is about 30 million DALYs.

“We found that for the vehicle operation phase of our LCIA, the annual health damages avoided in the U.S. with 10-percent less gasoline-run motor vehicle emissions ranges from about 5,000 to 20,000 DALY, with most of the damage resulting from primary fine particle emissions,” said McKone. “While county-specific damages range over nine orders of magnitude across all U.S. counties most of the damage, as you would expect, is concentrated in urban populations with the highest impact in the Los Angeles, New York and Chicago regions.”
Large urban regions also suffered disproportionate health damage as a result of benzene emissions at service stations and during the transporting by truck of gasoline to service stations - approximately 930 DALYs.

D: note that the health costs are borne by the nearby populations, not the purchaser of gasoline.

Again, gas ought to be 2x the price, if negative externalities were incorporated...