| Many factors affect an individual's
absorption of alcohol. These include weight, sex (a higher proportion
of a woman's body weight is in fat and fat absorbs less alcohol
than muscle tissue), amount of food in the digestive track,
and time spent drinking (and the corresponding rate of elimination).
BAC levels and the number of "typical"
drinks required to reach them can be roughly estimated. After
4 drinks in one hour, a male of 160 pounds will reach a BAC
of .07% and a female of 120 pounds will reach a BAC of .08%.
The following is a breakdown of skill set vs blood alcohol
levels
|
BAC Level
|
Impairment
|
|
.03 BAC
|
Choice
reaction time impaired |
|
.04 BAC
|
Simple
Reaction time
Emergency Response |
|
05 BAC
|
Tracking
divided attention
coordination
comprehension & eye movement |
|
.08 BAC
|
Concentration
attention
speed control
braking
gear changing
lane tracking |
What is the Risk?
The risk of being in a crash begins to rise between .04% and
.05% BAC, and increases rapidly thereafter. By the time a
driver reaches a BAC of .06% he or she is twice as likely
to be involved in a fatal crash as a non- drinking driver.
Additional alcohol increases the chance
of a fatal crash even more. A driver with a BAC of .10% to
.14% is about 50 times as likely to be in a fatal crash as
a non-drinking driver. The rate goes up as the BAC rises.
Know your personal limit of moderation
It is important to know the many factors affect impairment,
they are:
-Gender-
Because of differences in body composition and chemistry,
males and females are affected differently by alcohol. Men
generally have more muscles tissue and women more fatty tissue.
-Fatty Tissue-
Fatty tissue has a smaller blood supply than muscle tissue
so more of the alcohol goes into the bloodstream. The result
is that when a man and woman of equal weight drink equal amounts
of alcohol, the alcohol concentration level will be higher
in the woman.
-Time-
The number of hours a person drinks affects BAC. The body
slowly eliminates alcohol as follows: oxidation by the liver
(95%), breath (2%), urine (2%), and perspiration (1%). The
liver's rate of oxidation is constant and cannot be increased
by drinking coffee, physical activity, or by taking cold showers.
The body eliminates about one standard drink an hour.
-Strength-
The strenght of drink as mentioned above, all drinks are not
created equal. A mixed drink usually has more than 1-1/2 oz
of alcohol and the alcohol in different beers can vary as
much as 40%.
-Age-
This factors is rarely considered in discussion of BAC,
but it is important. The human body develops less tolerance
to alcohol with aging. This is due to a gradual change or
slowing down of the body's metabolic rate. In addition, the
ratio of body fat to muscle increases with age. As a result,
the same amount of alcohol intake per body weight consumed
by older people (after 55) can result in higher alcohol concentration
levels and the effects of alcohol last longer.
Age and drinking is a factor for young people. They become
involved in fatal crashes at significantly lower BAC than
adults. Their alcohol use disrupts their novice driving skill
at lower BAC levels.
What is the Risk?
The risk of being in a crash begins to rise between .04% and
.05% BAC, and increases rapidly thereafter. By the time a
driver reaches a BAC of .06% he or she is twice as likely
to be involved in a fatal crash as a non- drinking driver.
Additional alcohol increases the chance of a fatal crash even
more. A driver with a BAC of .10% to .14% is about 50 times
as likely to be in a fatal crash as a non-drinking driver,
and 380 times greater at a .15 and above
Information
from the National Highway Safety Administration and Nationwide
Insurance and the Minnesota Driver's Manual
|
