Ethanol, obtained from vegetable sources, is touted as a more eco-friendly fuel, than petroleum products. But a new study says that widespread use of ethanol could actually pose a threat to human health.
Ethanol, the wonder fuel, may not be that eco-friendly after all. The journey for ever is hitting some bumps. For a new study at the Stanford University in the US shows that it could be damaging to human health.
AdvertisementAtmospheric scientist Mark Z. Jacobson says that if every vehicle in the United States is powered by fuel made primarily from ethanol instead of gasoline, there would likely be an increase in the number of respiratory-related deaths and hospitalizations.
The study is in the April 18 online edition of the journal Environmental Science & Technology.
Jacobson used a computer model to simulate what air quality conditions in the United States would be in 2020, if there was widespread use of vehicles fueled by E85, a blend of 85 percent ethanol and 15 percent gasoline.
Ethanol is produced from renewable resources such as corn or sorghum and can be blended with gasoline as a 10% (E10) or 85% (E98) blend.
When 15% gasoline is blended with 85% ethanol, a fuel called E85 is created and can be used in vehicles classified by automobile manufacturers as Flexible Fuel Vehicles.
'We found that E85 vehicles reduce atmospheric levels of two carcinogens, benzene and butadiene, but increase two others - formaldehyde and acetaldehyde,' Jacobson said in a prepared statement. '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.'
The computer model showed ozone increases in Los Angeles and the northeastern U.S. , but a decrease of ozone in the southeast.
'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,' Jacobson said. 'These mortality rates represent an increase of about four percent in the U.S. and nine percent in Los Angeles above the projected ozone-related death rates for gasoline-fueled vehicles in 2020.' The study also found that E85 would likely increase the number of asthma-related emergency room visits in the United States by 770 a year and the number of respiratory-related hospitalizations by 990 a year.
The harmful effects of E85 would be the same, whether the ethanol is made from corn, switchgrass or other kinds of plants, Jacobson said. He questioned the wisdom of promoting ethanol and other biofuels if they cause as much harm as pollution from gasoline, which causes about 10,000 premature deaths a year in the United States.
'There are alternatives, such as battery-electric, plug-in hybrid and hydrogen fuel cell vehicles, whose energy can be derived from wind or solar power. These vehicles produce virtually no toxic emissions or greenhouse gases and cause very little disruption to the land - unlike ethanol made from corn or switchgrass, which will require millions of acres of farmland to mass-produce,' he said.
This finding should come as a serious blow to the ethanol lobby. There are any number of non-profit groups in the US promoting ethanol as the most acceptable alternative fuel.
· It provides high octane at low cost as an alternative to harmful fuel additives, is biodegradable without harmful effects on the environment, significantly reduces harmful exhaust emissions, ethanol blends dramatically reduce emissions of hydrocarbons, a major contributor to the depletion of the ozone layer and it can reduce net carbon dioxide emissions by up to 100% on a full life-cycle basis. As an octane enhancer, it can cut emissions of cancer-causing benzene and butadiene by more than 50%.
Such are the claims made. President George W Bush sees it as part of the solution to 'a serious problem: America is addicted to oil, which is often imported from unstable parts of the world.'
But then even before the Stanford study, it had been pointed out that as much greenhouse gas was released in producing corn ethanol as was saved in replacing gasoline by ethanol. Even in the case of sugarcane ethanol, the problem of relative energy inefficiency of ethanol remains.
A vehicle would burn 1.4 times as much E85 as straight gasoline, the U.S. Department of Energy says.
Besides, critics warned, large-scale diversion of the world's leading grain crop to the production of fuel will affect food prices everywhere. As the world corn price rises, so too do those of wheat and rice, both because of consumer substitution among grains and because the crops compete for land, they say.