The Alcohol Breath Test, a review

WARNING: SCIENCE CONTENT

In most states, police enforcement agencies utilize the Intoxilyzer 8000 or a similar machine to estimate blood alcohol content based on the amount of ethyl alcohol molecules expired in a single breath. Evidence from these machines is presented during trials as being reliable and accurate. If one suspect blows .079, he will likely be acquitted or charges won't even be filed; but if the same subject blows .080, prosecution will ensue. We are talking about a difference one one-thousandths of a percentage point that separate that guilty from the innocent when these machines are used. With so much on the line, lets discuss some of the science behind the machine:

1) The affect of body temperature: The machine assumes that all DUI suspects have a body temperature of 37 degrees Celsius and exhale their breath at 34 degrees Celsius. This assumption is based on research from 1950 involving 6 test subjects. These assumption have been studied by pulmonoligists and biologists since 1950. Several treatises in peer-reviewed articles conclusively show that the average person actually exhales at 35 degrees. This conclusion was reached in 1996 after observing 700 test subjects. So why does it matter? Research that compares BAC (measured by blood draws) and BrAC (breath alcohol content measured by a similar device) shows that for every degree of body temperature above the assumed 37 degrees results in an overestimation of BAC by 8.6%, with a maximum of a 23% overestimation (Fox & Hayward, both PhD's; Schoknect). By example: let's assume that I have a .079% BAC in my system at the time that I blow into the machine. Because I am very nervous, my heart rate increases as well as my body temperature, though only slightly by 1 degree. When I blow into the machine, the BrAC will register at .085%. Even though my BAC is in fact below the limit, it is likely that I will be convicted at trial merely because my body temperature is slightly elevated when I blew into the machine.

Now consider the role this plays when somebody during an Arizona summer leaves a barbeque at the lake after being in the hot sun all day.

2) Partition Ratio: Partition ratio derives from Henry's Law, which, in a nutshell, stands for the proposition that, in a closed container, a portion of the gas dissolved in a liquid will leave that liquid into the air above and reach equilibrium at a particular proportion. Let's think about it this way: ethyl alcohol is a gas when present in the blood stream. When the blood reaches the lungs, which operate enough like a closed container, the EtOH gas tranfers into the air above the liquid blood until a certain proportion is reached. The Intox. 8000 assumes that all people have a 2100:1 ratio, which means that for every 2100 EtOH particles in the blood, 1 such particle will be in the air above the blood in the lungs. It measures, by means of an electromagnetic wave, how many particles of EtOH are in a measured amount of air breathed into the machine, multiply it by a factor of 2100, to reach an estimation of BAC.

Here's the problem: depending on individual physiological differences from suspect to suspect (i.e. male/female, genetics, dehydration, health of the lungs, etc.) a person's partition ratio can vary 1600:1 to 2900:1. So why is this a problem? A DUI suspect with a 1600:1 partition ratio will have a breath test result 20% higher than his actual BAC--so if he is at a .07 actual BAC, his breath result will be well above the limit, and he will be unjustly convicted. A DUI suspect that has a 2600:1 ratio will have a result that is 20% lower than his actual BAC, resulting in a strong likelihood of sliding past prosecution with an actual BAC of .09%. Most people have a partition ratio between 1800:1 and 2400:1, but even the smaller variation has serious ramification on who is unjustly convicted and who get away with one.

3) The rest: Breathing patterns, lung capacity, whether the suspect is in the aborption/elimination phase of alcohol consumption, dispersion rate, hematocrit, and other factors play into the accuracy/reliability of the machine. These effects are usually not as significant, but play a role. I won't bore you with any more science.

I realize that many people are of the opinion that a person should be convicted of DUI after even one drink. Believe me--I completely understand those feelings; I have seen the effect of drunken driving. But that's not the point--the law is .08%, and that law needs to be applied uniformly to all people in such a way that the guilty are convicted and the innocent are exonerated. Yet, the states rely on a device clearly susceptible to variation, up to + or - 40%. This creates a strong public policy concern: How can law be applied uniformly where the primary investigative technique is inherently flawed? The solution is simple: draw blood, then these concerns fall.

Here is an article by a Professor of Pharmocology with a review of these issues:

http://forensic-evidence.com/site/Biol_Evid/Breath_Tests.html

We've been elfed!

http://www.elfyourself.com/?id=1135634580

4th and 18

I hung my head in disbelief after watching Utah take the lead with their only touchdown of the day with 1:30 remaining in the game. When Max Hall recovered his own fumble for an 8 yard loss, I felt somewhat hopeful that the first down could come. But then, after two straight incompletions, I became despondent--inconsolable. Then came the play.

4th and 18 from the BYU 12. Max Hall drops back, gets flushed from the pocket, runs to his right. "Okay," I thought, "buying a little time." Then he hurled this sort of jump pass down the sideline. "It's over," I thought, "we should have just kicked the field goal." When Austin Collie came into view on the right side of the screen, "Just keep it in bounds," I thought. What a beautiful sight: a 49 yard pass play on 4th and 18.

"We're going to win," I thought, "Go Cougars!"

Moccasin Justice Court

Here is a picture taken in front of the Colorado City/Moccasin Consolidated Court. It serves, as you can guess, Colorado City and Mohave County north of the Grand Canyon. It is a double wide trailer converted into a courthouse. To its credit, it is presided over by a very fair and genuinely concerned judge--and it has a very friendly cat that welcomes you. To get there, you have to drive north through Las Vegas, east to St. George, north to Hurricane, then South east to Mocassin, which is 20 miles south of Colorado City. The drive itself is beautiful. If I didn't know the Fundamentalist LDS church chose the location because it is secluded from "the world," I would think it was merely a decision involving how pretty the landscape is.

I represented a client in a domestic violence case. Ahhh, domestic violence--pretty much the bane of my existence. No category of cases gets to me quite the same way. It has cured me of any desire to practice family law. The problem with domestic violence is that everybody is a victim, especially the children. Also, while I don't have any real statistics to back it up, I would venture to say that at least 3/4 of the d.v. cases that run across my desk involve alcohol. The combination of strong emotion and stronger drink creates volatile situations. I don't envy the officers sent into those situations who hear completely different stories from those involved then have to make a determination about who is telling the truth and how to diffuse the problem. I, at least, don't get involved until things have calmed down substantially.

I often find it hard not to confuse my role of legal counselor with family counselor. I try not to cross the line very often by giving personal advice; I don't know if I ever should cross that line. It is essention to just sit and listen, though. Sometimes the public defender is the only one sitting a person's corner. Often, there isn't a whole lot I can do for the person other then help him or her feel understood. At the same time, I fight the temptation to chastise the man who beats his wife, or the woman who hurts her children. There is just no excuse for such behavior.

One year ago, I the work of a public defender was all about writing stinging motions to supress or "fighting the good fight" for the wrongfully accused. How could I have known that so much time would be spent wading through years strangers' family problems? Is it all worth it? Yeah, it is, 'cause every so often real change occurs for all involved. It's nice to be a part of that side.

And the winner is . . .

I know you've been waiting at the edge of your mouse pads for the results. Picture #1, which most of you got right, is the picture from Arizona. I plan to go back in the spring to spend a little more time down there. Staying just overnight didn't do justice, so I'm gnawing at the bit to go back.

On a more sad note, BYU is playing again today--in Las Vegas. I can't go in person. And the stupid mtn. has the broadcasting rights. The mtn. is the bane of my existence.

Supai, part II

I went to Supai, this time by foot, with some friends this past weekend. The hike is 10 miles, each way, which we did in 24 hours. The scenery at the end did not dissapoint. You tell me, which picture is from Hawaii, and which picture is from Arizona?

#1

#2

Which picture is from the falls in Arizona?
	# 1
	# 2
pollcode.com free polls

Here's to The Mtn.

If BYU dominates a previously undeafeted Air Force team, winning 31-6, and nobody see's it, did it really happen?

Let me throw my hat into the ring of those disgruntled fans that believe the MWC's new deal with CSTV/Comcast/The Mtn. was the worst thing that ever happened to BYU football. Even worse than the trying years under Gary Crowton and the unending suspensions after criminal charges! The fans can't see the games. I can't even get the games on pay-per-view for crying out loud. At least with SportsWest, which, admittedly, had very poor production and distribution in its own right, I could pick up a game on pay-per-view or Game Plan. Now I get nothing for half the season. Cheers to the Comcast lawyers--they wrote a contract so air tight that the MWC and BYU can't even come close to terminating the contract where there is no meaningful distribution of the games. Jeers to the MWC lawyers and Craig Thompson--suckers, blinded by illusory promises.

So here's to 7 years of looking forward to September and Cougar football, then hanging my head in sorrow each Saturday as the Coug's dominate opponents in the dark.