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 Win-win strategies for climate and food security
02.10.2017 | International Institute for Applied Systems Analysis (IIASA)

nachricht The personality factor: How to foster the sharing of research data
06.09.2017 | ZBW – Leibniz-Informationszentrum Wirtschaft

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: Neutron star merger directly observed for the first time

University of Maryland researchers contribute to historic detection of gravitational waves and light created by event

On August 17, 2017, at 12:41:04 UTC, scientists made the first direct observation of a merger between two neutron stars--the dense, collapsed cores that remain...

Im Focus: Breaking: the first light from two neutron stars merging

Seven new papers describe the first-ever detection of light from a gravitational wave source. The event, caused by two neutron stars colliding and merging together, was dubbed GW170817 because it sent ripples through space-time that reached Earth on 2017 August 17. Around the world, hundreds of excited astronomers mobilized quickly and were able to observe the event using numerous telescopes, providing a wealth of new data.

Previous detections of gravitational waves have all involved the merger of two black holes, a feat that won the 2017 Nobel Prize in Physics earlier this month....

Im Focus: Smart sensors for efficient processes

Material defects in end products can quickly result in failures in many areas of industry, and have a massive impact on the safe use of their products. This is why, in the field of quality assurance, intelligent, nondestructive sensor systems play a key role. They allow testing components and parts in a rapid and cost-efficient manner without destroying the actual product or changing its surface. Experts from the Fraunhofer IZFP in Saarbrücken will be presenting two exhibits at the Blechexpo in Stuttgart from 7–10 November 2017 that allow fast, reliable, and automated characterization of materials and detection of defects (Hall 5, Booth 5306).

When quality testing uses time-consuming destructive test methods, it can result in enormous costs due to damaging or destroying the products. And given that...

Im Focus: Cold molecules on collision course

Using a new cooling technique MPQ scientists succeed at observing collisions in a dense beam of cold and slow dipolar molecules.

How do chemical reactions proceed at extremely low temperatures? The answer requires the investigation of molecular samples that are cold, dense, and slow at...

Im Focus: Shrinking the proton again!

Scientists from the Max Planck Institute of Quantum Optics, using high precision laser spectroscopy of atomic hydrogen, confirm the surprisingly small value of the proton radius determined from muonic hydrogen.

It was one of the breakthroughs of the year 2010: Laser spectroscopy of muonic hydrogen resulted in a value for the proton charge radius that was significantly...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ASEAN Member States discuss the future role of renewable energy

17.10.2017 | Event News

World Health Summit 2017: International experts set the course for the future of Global Health

10.10.2017 | Event News

Climate Engineering Conference 2017 Opens in Berlin

10.10.2017 | Event News

 
Latest News

Terahertz spectroscopy goes nano

20.10.2017 | Information Technology

Strange but true: Turning a material upside down can sometimes make it softer

20.10.2017 | Materials Sciences

NRL clarifies valley polarization for electronic and optoelectronic technologies

20.10.2017 | Interdisciplinary Research

VideoLinks
B2B-VideoLinks
More VideoLinks >>>