14 DAY TRIAL // It is seen as the universal solution to oil crisis.
Ethanol is promoted as an environmentally friendly and renewable fuel, as it is achieved from the fermentation corn and other crops or even from plant wastes.
The carbon dioxide resulted from burning ethanol would be equal to that soaked up from atmosphere by the plants from which is made, thus it would not damp supplementary carbon dioxide into the atmosphere, like oil based fuels do.
But its ecologically friendly image was dashed by the fact that crops aimed for its production engulf large portions of pristine habitats, especially in the virgin tropical rainforests.
Now, ethanol combustion was found to be even more toxic than gasoline one for the human health. ''Ethanol is being promoted as a clean and renewable fuel that will reduce global warming and air pollution,'' said Stanford University atmospheric scientist Mark Jacobson.
But his analyses show that the number of deaths and hospitalizations connected to breathing problems would rise if vehicles used fuel with high ethanol levels.
A 3-D atmospheric computer model mimicked air composition in 2020, when ethanol-fueled vehicles could be common in the US, in two scenarios: all vehicles fueled by gasoline or by E85, a popular blend of 85 % ethanol and 15 % gasoline. ''We found that E85 vehicles reduce atmospheric levels of two carcinogens, benzene and butadiene, but increase two others, formaldehyde and acetaldehyde. As a result, cancer rates for E85 are likely to be similar to those for gasoline. However, in some parts of the country, E85 significantly increased ozone, a prime ingredient of smog',' Jacobson said.
E85 could rise ozone levels in the LA area and the northeastern US but to reduce it in the southeast US, due to differences in airborne pollutants (like nitrogen oxides or volatile biochemicals) composition at different locations, reacting differently with E85 combustion products.
"Gasoline currently leads to roughly 10,000 premature deaths in the United States annually from ozone and particulate matter. In our study, E85 increased ozone-related mortalities in the United States by about 200 deaths per year compared to gasoline, with about 120 of those deaths occurring in Los Angeles. These mortality rates represent an increase of about 4 % in the U.S.'' said Jacobson.
"We found that nationwide, E85 is likely to increase the annual number of asthma-related emergency room visits by 770 and the number of respiratory-related hospitalizations by 990. These numbers might change if better ways to treat ethanol fuel emissions develop in the next 10 years," Jacobson said.
"But based on what we currently know, ethanol is at least as bad to public health as gasoline, and possibly worse. There are technologies we can use instead of any type of combustion engine that would result in no tailpipe deaths, such as battery-electric vehicles whose energy can come from wind or solar power."
"It's been known for a long time that E85 is not the cleanest fuel in the world. Regulatory agencies will have to keep on top of this issue to make sure things don't go awry", signaled atmospheric chemist Roger Atkinson at the University of California, Riverside.