|
Measuring Alcohol in the Body
Alcohol concentration in the body is usually determined by measuring:
Blood alcohol concentration (BAC)
Breath alcohol concentration (BrAC)
Blood alcohol concentration (BAC)
When alcohol is consumed, it is absorbed into the blood stream,
hence the drinker's blood alcohol level rises when alcohol is consumed.
When a person drinks more alcohol than his or her body can eliminate,
alcohol accumulates in the blood stream and the blood alcohol concentration
(BAC) rises.
BAC is commonly expressed in milligrams per deciliter (mg/dL).
Using this measure, 100 mg/dL roughly is equal to 1 part alcohol
in 1000 parts of water (or blood). Consequently, 100 mg/dL would
be equal to a 0.1% concentration.
The following table lists the approximate BAC of men and women
after drinking (A number of factors affect the metabolism of alcohol
and thus the following BAC is for reference only):
|
Men
|
Approximate Blood Alcohol Concentration (BAC) |
|
|
Body Weight in Pounds |
|
Drinks
|
100 |
120 |
140 |
160 |
180 |
200 |
220 |
240 |
|
1
|
.04 |
.03 |
.03 |
.02 |
.02 |
.02 |
.02 |
.02 |
|
2
|
.08 |
.06 |
.05 |
.05 |
.04 |
.04 |
.03 |
.03 |
|
3
|
.11 |
.09 |
.08 |
.07 |
.06 |
.06 |
.05 |
.05 |
|
4
|
.15 |
.12 |
.11 |
.09 |
.08 |
.08 |
.07 |
.06 |
|
5
|
.19 |
.16 |
.13 |
.12 |
.11 |
.09 |
.09 |
.08 |
|
6
|
.23 |
.19 |
.16 |
.14 |
.13 |
.11 |
.10 |
.09 |
|
7
|
.26 |
.22 |
.19 |
.16 |
.15 |
.13 |
.12 |
.11 |
|
8
|
.30 |
.25 |
.21 |
.19 |
.17 |
.15 |
.14 |
.13 |
|
9
|
.34 |
.28 |
.24 |
.21 |
.19 |
.17 |
.15 |
.14 |
|
10
|
.38 |
.31 |
.27 |
.23 |
.21 |
.19 |
.17 |
.16 |
|
Subtract .01% for each 40 minutes of drinking.
One drink is 1.25 oz. of 80 proof liquor, 12 oz. of beer,
or 5 oz. of table wine.
|
|
Women
|
Approximate Blood Alcohol Concentration (BAC) |
|
|
Body Weight in Pounds |
|
Drinks
|
90 |
100 |
120 |
140 |
160 |
180 |
200 |
220 |
240 |
|
1
|
.05 |
.05 |
.04 |
.03 |
.03 |
.03 |
.02 |
.02 |
.02 |
|
2
|
.10 |
.09 |
.08 |
.07 |
.06 |
.05 |
.05 |
.04 |
.04 |
|
3
|
.15 |
.14 |
.11 |
.10 |
.09 |
.08 |
.07 |
.06 |
.06 |
|
4
|
.20 |
.18 |
.15 |
.13 |
.11 |
.10 |
.09 |
.08 |
.08 |
|
5
|
.25 |
.23 |
.19 |
.16 |
.14 |
.13 |
.11 |
.10 |
.09 |
|
6
|
.30 |
.27 |
.23 |
.19 |
.17 |
.15 |
.14 |
.12 |
.11 |
|
7
|
.35 |
.32 |
.27 |
.23 |
.20 |
.18 |
.16 |
.14 |
.13 |
|
8
|
.40 |
.36 |
.30 |
.26 |
.23 |
.20 |
.18 |
.17 |
.15 |
|
9
|
.45 |
.41 |
.34 |
.29 |
.26 |
.23 |
.20 |
.19 |
.17 |
|
10
|
.51 |
.45 |
.38 |
.32 |
.28 |
.25 |
.23 |
.21 |
.19 |
|
Subtract .01% for each 40 minutes of drinking.
One drink is 1.25 oz. of 80 proof liquor, 12 oz. of beer,
or 5 oz. of table wine.
|
Breath alcohol concentration (BrAC)
When alcohol is consumed, it is absorbed into the blood stream. In
the alveoli of the lungs, the alcohol entered the air from the thin
tissue layer between the alveoli and the blood stream. The exchange
of alcohol to the breath occurs in this deep lung region.
The concentration of alcohol in breath is proportional to the concentration
of alcohol in blood. Hence, alcohol concentration in our body could
also be measured by its concentration in our breath.
The widely accepted blood:breath ratio of 2100:1 is used in computing
blood alcohol concentration (BAC) from breath alcohol concentration.(BrAC).
|
