Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Ethanol vehicles pose a significant risk to human health

20.04.2007
Ethanol is widely touted as an eco-friendly, clean-burning fuel. But if every vehicle in the United States ran on fuel made primarily from ethanol instead of pure gasoline, the number of respiratory-related deaths and hospitalizations would likely increase, according to a new study by Stanford University atmospheric scientist Mark Z. Jacobson. His findings are published in the April 18 online edition of the journal Environmental Science & Technology (ES&T).

''Ethanol is being promoted as a clean and renewable fuel that will reduce global warming and air pollution,'' said Jacobson, associate professor of civil and environmental engineering. ''But our results show that a high blend of ethanol poses an equal or greater risk to public health than gasoline, which already causes significant health damage.''

Gasoline vs. ethanol

For the study, Jacobson used a sophisticated computer model to simulate air quality in the year 2020, when ethanol-fueled vehicles are expected to be widely available in the United States.

''The chemicals that come out of a tailpipe are affected by a variety of factors, including chemical reactions, temperatures, sunlight, clouds, wind and precipitation,'' he explained. ''In addition, overall health effects depend on exposure to these airborne chemicals, which varies from region to region. Ours is the first ethanol study that takes into account population distribution and the complex environmental interactions.''

In the experiment, Jacobson ran a series of computer tests simulating atmospheric conditions throughout the United States in 2020, with a special focus on Los Angeles. ''Since Los Angeles has historically been the most polluted airshed in the U.S., the testbed for nearly all U.S. air pollution regulation and home to about 6 percent of the U.S. population, it is also ideal for a more detailed study,'' he wrote.

Jacobson programmed the computer to run air quality simulations comparing two future scenarios:

- A vehicle fleet (that is, all cars, trucks, motorcycles, etc., in the United States) fueled by gasoline, versus

- A fleet powered by E85, a popular blend of 85 percent ethanol and 15 percent gasoline.

Deaths and hospitalizations

The results of the computer simulations were striking.

''We found that E85 vehicles reduce atmospheric levels of two carcinogens, benzene and butadiene, but increase two others-formaldehyde and acetaldehyde,'' Jacobson said. ''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.''

Inhaling ozone-even at low levels-can decrease lung capacity, inflame lung tissue, worsen asthma and impair the body's immune system, according to the Environmental Protection Agency. The World Health Organization estimates that 800,000 people die each year from ozone and other chemicals in smog.

''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 4 percent in the U.S. and 9 percent in Los Angeles above the projected ozone-related death rates for gasoline-fueled vehicles in 2020.''

The study showed that ozone increases in Los Angeles and the northeastern United States will be partially offset by decreases in the southeast. ''However, 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,'' Jacobson said. ''Los Angeles can expect 650 more hospitalizations in 2020, along with 1,200 additional asthma-related emergency visits.''

The deleterious health effects of E85 will be the same, whether the ethanol is made from corn, switchgrass or other plant products, Jacobson noted. ''Today, there is a lot of investment in ethanol,'' he said. ''But we found that using E85 will cause at least as much health damage as gasoline, which already causes about 10,000 U.S. premature deaths annually from ozone and particulate matter. The question is, if we're not getting any health benefits, then why continue to promote ethanol and other biofuels?

''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,'' he added. ''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. It would seem prudent, therefore, to address climate, health and energy with technologies that have known benefits. ''

Mark Shwartz | EurekAlert!
Further information:
http://www.stanford.edu

More articles from Studies and Analyses:

nachricht Real-time feedback helps save energy and water
08.02.2017 | Otto-Friedrich-Universität Bamberg

nachricht The Great Unknown: Risk-Taking Behavior in Adolescents
19.01.2017 | Max-Planck-Institut für Bildungsforschung

All articles from Studies and Analyses >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Safe glide at total engine failure with ELA-inside

On January 15, 2009, Chesley B. Sullenberger was celebrated world-wide: after the two engines had failed due to bird strike, he and his flight crew succeeded after a glide flight with an Airbus A320 in ditching on the Hudson River. All 155 people on board were saved.

On January 15, 2009, Chesley B. Sullenberger was celebrated world-wide: after the two engines had failed due to bird strike, he and his flight crew succeeded...

Im Focus: Breakthrough with a chain of gold atoms

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

Im Focus: DNA repair: a new letter in the cell alphabet

Results reveal how discoveries may be hidden in scientific “blind spots”

Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...

Im Focus: Dresdner scientists print tomorrow’s world

The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.

The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...

Im Focus: Mimicking nature's cellular architectures via 3-D printing

Research offers new level of control over the structure of 3-D printed materials

Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Booth and panel discussion – The Lindau Nobel Laureate Meetings at the AAAS 2017 Annual Meeting

13.02.2017 | Event News

Complex Loading versus Hidden Reserves

10.02.2017 | Event News

International Conference on Crystal Growth in Freiburg

09.02.2017 | Event News

 
Latest News

New technology offers fast peptide synthesis

28.02.2017 | Life Sciences

WSU research advances energy savings for oil, gas industries

28.02.2017 | Power and Electrical Engineering

Who can find the fish that makes the best sound?

28.02.2017 | Information Technology

VideoLinks
B2B-VideoLinks
More VideoLinks >>>