Can Dieting Cause False Breathalyzer Readings?

Monday, February 17th, 2014

I’ve written in the past about how most so-called "breathalyzers" do not measure alcohol:  they actually measure the presence of the methyl group in chemical compounds.  One of those compounds is ethyl alcohol (aka ethanol), and the machine simply assumes that the detected compound is ethyl alcohol. 

Problem:  there are thousands of compounds containing the methyl group — of which over one hundred have been found on the human breath.  Breathing gasoline or paint fumes, for example, or merely absorbing the fumes through the skin, can create false breath test results for days afterwards.  And I’ve posted that the problem is particularly acute when the suspect happens to be a diabetic, as diabetics often have high levels of acetone in their breath — a compound which contains the methyl group. 

However, you don’t have to be a diabetic to have high levels of acetone:  scientific research has established that acetone can exist in perfectly normal individuals at  levels sufficient to cause false high breath-alcohol test readings.  See "Excretion of Low-Molecular Weight Volatile Substances in Human Breath:  Focus on Endogenous Ethanol", 9 Journal of Analytical Toxicology 246 (1985). 

Fasting or radical dieting, such as with the Atkins diet, can also cause significantly elevated acetone.  Studies have concluded that fasting can increase acetone in the body sufficient to obtain breathalyzer readings of .06% (this is cumulative — that is, the .06% will be added by the machine to any levels actually caused by alcohol or other compounds).   See "The Likelihood of Acetone Interference in Breath Alcohol Measurement", 3  Alcohol, Drugs and Driving 1 (1987).  And low-carbohydrate diets, such as Atkins, have long been associated with high levels of acetone production.

Of course, for many years law enforcement denied that any such problem existed, just as they denied that mouth alcohol and radio frequency interference caused false test results — until manufacturers started adding acetone detectors, mouth alcohol detectors and RFI detectors to their machines (none of which, unfortunately, have proven reliable.) 

How reliable are breathalyzers?  "Close enough for government work".  As I’ve posted, there seems to be a growing trend toward letting officers draw blood themselves at the scene of arrest.  Given the reassurances about these machines so often expressed publicly by law enforcement, one has to wonder why they are increasingly turning to the involved process of hypodermic needles, preservatives, anticoagulents, refrigeration and delayed laboratory analysis….
 

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Circadian Rhythm and Field Sobriety Tests

Sunday, February 2nd, 2014

Most drunk driving arrests take place at night, often well after midnight. One reason for this is that many police officers engage in "cherry picking" — that is, the illegal practice of staking out bars and restaurants from about 10:00pm to "closing time" at around 2:00am, pulling cars over on some pretext as patrons leave and drive away.

It is during this period of time that the individual’s circadian rhythm is taking effect. This is the 24-hour biological alarm clock in each of our bodies, often noticeable when we experience "jet lag".

Researchers have found that individuals will perform more poorly in tests during the low point of the circadian rhythm — that is, during the hours after midnight and into the early morning.

Unfortunately, it is just such tests — called "field sobriety tests" — that officers use to determine whether a driver is intoxicated or not.

British physicians and psychiatrists reported that "the same blood alcohol level is associated with a significantly greater impairment of different aspects of psychological funtioning when achieved in the morning." "Circadian Variation in Effects of Ethanol in Man", 18 (Supp. 1) Pharmacology, Biochemistry and Behavior 555.

The researchers concluded that "the differences we have found (in field sobriety test performances)…must be attributable to circadian change and susceptibility of the body to its effect."
 

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High Breath Alcohol?…or Just Pumping Gasoline?

Monday, January 27th, 2014

Folks who have read my post, "Why Breathalyzers Don’t Measure Alcohol", seem quite surprised to find out these DUI machines are not as reliable as MADD and law enforcement agencies would have us believe. In fact, the manufacturers of some of these machines have refused in the past to even warrant them to do what they’re supposed to: accurately measure blood-alcohol levels (see my earlier post, "Breathalyzers: Why Aren’t They Warranted to Measure Alcohol?")

So how reliable are these "breathalyzers" that determine a person’s guilt or innocence in DUI cases? And just what do they measure?

Well, thousands of different chemical compounds, according to scientists. Gasoline for one. Consider an article appearing on the front page of the Spokane Spokesman-Review in which a person sitting in jail awaiting trial for DUI claimed that he had nothing to drink. He said he had run out of gas and had been siphoning gasoline from a container into his tank before being stopped by the officer and arrested. In siphoning, he had sucked on the hose to get it started and accidentally swallowed a small amount of the gasoline. He claimed that this must have caused the later high breathalyzer reading. The individual finally talked the sheriff into a demonstration to prove his story.

Taken from his cell after one week of incarceration, he swallowed a cup of unleaded gasoline and then blew into the breath machine — in this case, an Intoximeter 3000. The results? After 5 minutes, the reading was .00%…..after 10 minutes, .04%……after 20 minutes, the Intoximeter registered .31%…..and after one hour, the reading was .28%. Even after three hours, the person still blew a .24% on the machine — three times the legal limit! (A quick call from the sheriff to a local gasoline distributor confirmed that gasoline contains no alcohol.)

This was not a freak occurrence. The results have been scientifically verified in a study conducted by CMI, Inc., the manufacturer of a competing breath machine, the Intoxilyzer 5000, and reported in 8(3) Drinking/Driving Law Letter 6. The CMI technicians mixed a simulator solution of 800 micrograms of gasoline with 500 milliliters of distilled water, then introduced it into their machine. The solution produced readings of .619%, .631% and .635% — or about eight times the legal limit for "alcohol" levels.

You don’t have to drink gasoline to get a reading on the breathalyzer. Breathing the fumes will do it. Or even absorbing fumes through the skin.  Like at a gasoline pump.
 

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