Sunday, November 26, 2006

What is Acetaldehyde?

As promised in my post yesterday, here is a bit more info on Acetaldehyde.

Acetaldehyde is probably best known as the chemical that causes "hangovers". One of the major toxins produced from Candida albicans is acetaldehyde, which is transformed by the liver to ethanol (alcohol), creating the feeling of intoxication and brain fog. It's been said there have been cases where Candida patients have been pulled over and tested positive with elevated blood alcohol levels above normal, even though they had not even touched a drop of alcohol. But there's a more hazardous connection to cancer here...

Acetaldehyde is more toxic than ethanol and is responsible for many hangover symptoms. It is also an air pollutant, emitted by cars and certain production facilities. And it is also contained in tobacco smoke, contributing to the smoke's addictive properties.

Acetaldehyde is a Hazardous Air Pollutant (HAP), and was identified as a toxic air contaminant (TAC) by the California Environmental Protection Agency on April 8, 1993, when the Air Resources Board (ARB) identified all 189 HAPs as TACs. Quote:
The [California] ARB staff has determined that acetaldehyde is the product of incomplete combustion, is emitted from a variety of sources, and can be detected in the ambient air throughout California. It can be formed in polluted ambient atmospheres from a variety of precursors. It is highly mobile in the environment, and is not naturally removed or detoxified at a rate that would significantly reduce public exposure. The International Agency for Research on Cancer (IARC) classified acetaldehyde as a possible human carcinogen 2B), based on sufficient evidence in animals and inadequate evidence in humans. The United States Environmental Protection Agency (U.S. EPA) has decided that acetaldehyde is a "probable human carcinogen" (B2).

The OEHHA staff has concluded that at ambient concentrations acetaldehyde may cause or contribute to an increase in mortality or serious illness and may therefore pose a potential hazard to human health.

What are the sources of Acetaldehyde emissions (in addition to ethanol fueled vehicles)?

According the California EPA report referenced above, "The largest sources statewide of directly emitted acetaldehyde are from combustion of fuels from mobile sources, agricultural burning, and wildfires. Direct sources are estimated to contribute approximately 44 percent of the acetaldehyde in the atmosphere."

In 1999, IDEM in it's statewide inventory of toxic air contaminants, reported an Indiana Acetaldehyde emissions inventory of 233,592.33 lb/yr, as follows:

Point Sources: 189,570.00
Area Sources: 44,022.33

About Point Source Emissions: As part of the annual emissions reporting package Indiana requests information on hazardous air pollutant emissions from point sources required to report to STEPS. Indiana has included this voluntarily reported information, and information from the TRI database, for many point sources. The voluntarily reported emissions and TRI data are primarily source totals, however some sources did report process level HAPs in STEPS.

Now, I don't know but I've been told, acetaldehyde has a sickly sweet "fruity" smell... however, the California EPA report referenced above states:
Acetaldehyde is a colorless, flammable liquid, volatile at ambient temperature and pressure, with an irritating odor.

By the way, did you know...? When MTBE is removed and ethanol is added to gasoline, the vapor pressure (Rvp) of the gasoline blend increases and thus emissions of volatile organic compound (VOC) increase. See this very detailed government document which discusses the difficulties associated with replacing MBTE (now banned in several states) with ethanol.

It also reveals a few other problems with gas prices and ethanol that many of us may not be aware of.

More on health issues relating specifically to Dairy CAFOs later this week.


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