Ethanol in cars causing cancers?

Is ethanol added to gasoline causing cancers?

From an article in the Economist.

If 36 billion gallons of ethanol are to be produced from corn, as mandated by the Energy Independence and Security Act of 2007, America will be diverting all its current field-corn capacity to ethanol production by 2022.

To meet the needs for just domestic animal feed, as well as ethanol production, farmers will then have to devote additional acreage normally reserved for food crops to growing yet more field corn. Whether mandated or not, market forces will impel them to do so.

After tetra-ethyl lead was banned from petrol for health reasons in the 1990s, the octane-boosting additive of choice was methyl tertiary-butyl ether. But MBTE was later found to have its own problems (it contaminated drinking water supplies), and was replaced with ethanol. Since then, ethanol has been added to petrol in increasing quantities—not for health, environmental or performance reasons, but solely to fulfill the mandated requirements set by the politically charged RFS programme.

While the ethanol added to petrol helps the air-fuel mixture in the engine burn smoothly rather than explode prematurely (ie, “knock”) when under heavy load, it does not give the fuel more punch. In fact, the consensus is that motorists get 5-10% fewer miles to the gallon from petrol containing 10% ethanol (E10) compared with pure petrol. They do 25-30% worse when switching from E10 to E85.

The ethanol lobby plays up the fact that ethanol produces fewer harmful emissions of carbon monoxide, nitrogen oxides and particulate matter than either petrol or diesel. That is all true. But what is rarely mentioned is that, when burned in a car engine, ethanol produces significantly larger quantities of formaldehyde and related compounds such as acetaldehyde.

The United States government has declared formaldehyde a carcinogen, and lists acetaldehyde as a probable carcinogen. Such compounds are also adept at triggering photochemical reactions. As such, they generate greater amounts of ground-level ozone. Overall, an ethanol exhaust produces over twice as much ozone as a petrol engine’s. That means more smog. So much so that the California Air Resources Board—ever concerned about the millions of vehicles in the Los Angeles basin, with its pollution-trapping inversion layer—has set special emission standards for formaldehyde and its relatives alongside those for nitrogen oxides and other pollutants.

Read more of this Economist article here.

Advertisements