Breath Testing After One
for the Road
Information courtesy of Lawrence Taylor - DUIblog
Its a common situation. Youre at a restaurant, its been a fine meal, youve paid the bill and its time to head home. You finish off the glass of wine and head for the car.
A few blocks from the restaurant, youre stopped for speeding. The officer smells the wine still on your breath and asks you to step out of the car. A few minutes later and youre on the way to the police station -- and a breathalyzer. But you know that you and your wife each had only two glasses of wine from the bottle with dinner. The charts say that at your weight your blood-alcohol level should be around .05%, so youre well under the .08% legal limit, right? Wrong: the reading is .10%, your license is confiscated and you are booked for DUI.
What happened was what the toxicologists call "absorptive stage analysis". In English, your breath sample was tested while your body was still absorbing the alcohol from the last drink. Any testing during this stage of absorption will result in falsely high blood-alcohol readings.
Explanation.....Your body will continue absorbing alcohol for roughly an hour after drinking, reaching peak blood-alcohol levels sometime before that point; the presence of food in the stomach can delay this for as much as 4 hours. During this one-hour period, the alcohol is passing from the stomach and intestine into the blood, but has not yet reached a stage of "equilibrium" -- that is, uniform distribution of alcohol throughout the body. In other words, some parts of the body will have higher levels of alcohol than others -- in some cases, far higher. Since the alcohol is initially passing into the arteries, arterial blood will be much higher in alcohol content than will venous blood.
Where does the alcohol come from that is being measured by the breathalyzer? Thats right: the arteries.