The US study, ‘Effects of Ethanol (E85) versus Gasoline Vehicles on Cancer and Mortality in the United States’, by Stanford University scientist Mark Jacobson also showed E85 could increase levels of the air pollutant ozone, which would increase related mortality, hospitalisation and asthma by about 4% throughout the US, peaking at 9% in Los Angeles.
“Due to its ozone effects, future E85 may be a greater overall public health risk than gasoline,” Jacobson said in the report.
“However, because of the uncertainty in future emission regulations, it can be concluded with confidence only that E85 is unlikely to improve air quality over future gasoline vehicles.”
Jacobson used computer modelling to simulate air quality in 2020, when ethanol is expected to be widely available throughout the US, and compared death and hospitalisation rates where the vehicle fleet is fuelled by petrol and where it is powered by E85.
“Ethanol use in vehicle fuel is increasing worldwide, but the potential cancer risk and ozone-related health consequences of a large-scale conversion from gasoline to ethanol have not been examined,” he said.
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 petrol. However, in some parts of the country E85 significantly increased ozone, a prime ingredient of smog.
Inhaling ozone can decrease lung capacity, inflame lung tissue, worsen asthma and impair the body's immune system, according to a Stanford University overview of the study. The World Health Organisation estimates that 800,000 people die each year from ozone and other chemicals in smog.
In Australia, the Federal Government has cleared E10 for use in modern cars, but has shied away from higher rates citing concerns over the mechanical impact on engines.
