A recent study has proved that a biofuel eliminating even 10-percent of current gasoline pollutant emissions may have significant benefits for human health.
While the focus of a shift from gasoline to biofuels has been on global warming, such a shift could also impact human health.
A grant from the Energy Biosciences Institute (EBI) has produced a novel and comprehensive "Life Cycle Impact Assessment" (LCIA) to measure the benefits on human health that might result from a switch to biofuels.
Although there are a number of uncertainties that must be addressed for a more accurate picture, these early results show that a biofuel eliminating even 10-percent of current gasoline pollutant emissions would have a substantial impact on human health, especially in urban areas.
Assessments of the life cycle impacts of emissions from gasoline-run motors in the US on a county-by-county basis show that the heaviest damage (darkest coloring) is concentrated in urban areas, especially Los Angeles, New York and Chicago.
Nonetheless, Thomas McKone, an expert on health risk assessments and EBI researcher Agnes 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).
"In looking at emission impacts on health, we have the capacity to carry out county-level resolution measurements for both direct and indirect emissions," said McKone.
Measured emissions at county-level resolution included direct particulate matter and indirect fine particles (2.5 micrometers in diameter or smaller) produced from emissions of sulfate and nitrite gases, volatile organic compounds and ammonia, plus ozone, toxic air pollutants, emissions to surface and ground water, and emissions to soil.
"We found that for the vehicle operation phase of our LCIA, the annual health damages avoided in the US 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 US 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," he added.