Understanding Alcohol
sponsoring Institutes
Main Getting Started Teacher's Guide Student Activities About NIH and NIAAA
glossary | map | contact 
National Institutes of Health website National Institute on Alcohol Abuse and Alcoholism (NIAAA) website

National Institutes of Health
National Institute on Alcohol Abuse and Alcoholism

Understanding Alcohol

Main    Getting Started    Teacher's Guide    Student Activities    About NIH and NIAAA

Glossary    Map    Contact

Teacher's Guide hand using a mouse

Teacher's Guide

Lesson 5—Elaborate

Alcohol and Driving: When to Say No

At a Glance

Figure 5.1. Police officer watching a driver walk heel to toe on a road
Figure 5.1.
Police administer sobriety tests to help keep drivers under the influence of alcohol off the road.

Overview

Students investigate how drinking alcoholic beverages affects the blood alcohol concentration (BAC). They then explore how gender, body weight, metabolism, and drinking patterns change BAC. Finally, students watch driving simulations in a Web-based activity and consider how mental and physical functions are impaired by drinking alcohol.

Major Concepts

Alcohol impairs the functions of the mind and body. These impairments depend on the amount of alcohol in the blood, as measured by the blood alcohol concentration. Factors that influence the BAC include the number of drinks and the time period over which they are consumed, as well as the drinker’s gender and body weight. The body breaks down, or metabolizes, alcohol at a relatively constant rate, regardless of the rate at which it is consumed.

Objectives

After completing this lesson, students will

Teacher Background

Consult the following sections in Information about Alcohol:

  1. 5 Alcohol: Pharmacokinetics
  2. 5.1 Absorption and distribution of alcohol in the body
  3. 5.2 Measurement of blood alcohol concentration (BAC)
  4. 5.3 Factors affecting alcohol absorption and elimination
  5. 5.4 Alcohol metabolism
  6. 6 Alcohol: Biological Effects
  7. 6.1 Alcohol and the brain
  8. 6.2 Alcohol and body systems
  9. 10.2 Drinking and driving

In Advance

Web-Based Activities
Activity Web Version?
1 No
2 Yes
Photocopies
Activity 1 Master 5.1, Blood Alcohol Concentration Tables (Make 1 copy per student and prepare an overhead transparency.)
Master 5.2, Drinking Patterns for Party Guests (Make 1 copy per student team.)
Master 5.3, Blood Alcohol Concentration Graph Template (Make 1 copy per student team and prepare an overhead transparency.)
Activity 2 Master 5.4, Progressive Effects of Alcohol (Make 1 copy per student team and prepare an overhead transparency.)
Materials
Activity 1 colored pencils
Activity 2 computers with Internet access and sound card

Preparation

Gather supplies needed for the activities.
Arrange for access to computers.
Test the Internet connection and set up the appropriate bookmark to http://science.education.nih.gov/supplements/alcohol/student.
Students will need copies of Master 5.1, Blood Alcohol Concentration Tables, and Master 5.4, Progressive Effects of Alcohol, during Lesson 6.

Procedure

Activity 1: Patterns of Drinking

  1. Introduce the activity by creating a scenario for students. If two individuals attend a party and drink the same amount of alcohol, will they be affected in the same way? Ask students to share the reasons for their responses.

Students will respond that not all people react the same way to drinking the same amount of alcohol. Continue the discussion by asking the class to name factors that influence the extent to which a person is affected by drinking an alcoholic beverage. Accept all reasonable responses and list them on the board. Make sure that drinking pattern (whether the alcohol is consumed all at once or spread out over a long period of time) is mentioned.

  1. Inform students that they will investigate how drinking affects people differently. First, they need to recall some information from previous lessons. Review with the students what happens to alcohol after it has been consumed and what factors help determine an individual’s response to alcohol.
assessment icon
Assessment:
The discussion in Steps 1 and 2 provides an opportunity to evaluate what students recall from earlier lessons in the module. For example, do they recall that a 12-ounce beer contains the same amount of alcohol as 5 ounces of wine and 1.5 ounces of hard liquor? Do they understand that alcohol is absorbed into the bloodstream and is distributed throughout the body? Can students explain that an individual’s response to alcohol depends on factors such as the amount of alcohol consumed, the time after consumption, and individual genetic variation?

As they learned in Lesson 2, students should mention that the alcohol is carried throughout the body and is quickly absorbed from the stomach and small intestine into the bloodstream. If necessary, remind the class that alcohol distributes throughout the water-containing parts of the body and that the brain is especially sensitive to its effects. Students should recall from Lesson 3 that the amount of alcohol consumed, the time after consumption, and the genetic background of the individual are important factors in determining an individual’s response to drinking alcohol.

Figure 5.2
Figure 5.2. Once consumed, alcohol is absorbed through the stomach (1) and small intestine and enters the bloodstream (2), which distributes the alcohol to other parts of the body, including the brain (3).
  1. Give each student a copy of Master 5.1, Blood Alcohol Concentration Tables. Explain that the concentration of alcohol in the blood is expressed as weight of alcohol in a specific volume of blood. In the United States, the measure is grams of alcohol per 100 milliliters of blood, and it is reported as a percent. For example, 0.05 grams of alcohol in 100 milliliters of blood corresponds to a blood alcohol concentration (BAC) of 0.05 percent. Help students understand how to read the BAC tables by providing an example using the transparency of Master 5.1, such as what would the BAC be for a 120-pound female who consumes two alcoholic drinks in an hour?

If students look at the column for 120 pounds (third column from the left in the table for women at the top of Master 5.1) and read down to the row for 2 drinks, the BAC would be 0.08 percent.

Blood Alcohol Concentration Table: For Women
 
Body weight in pounds
Drinks per hour 100 120 140 160 180 200 220 240
1 0.05 0.04 0.03 0.03 0.03 0.02 0.02 0.02
2 0.09 0.08 0.07 0.06 0.05 0.05 0.04 0.04
3 0.14 0.11 0.10 0.09 0.08 0.07 0.06 0.06
  1. Ask the class what happens to a person’s BAC after it reaches the value listed in the table. After you establish that the BAC gradually declines, ask the class why this occurs.

Make sure the discussion brings out the fact that the BAC declines slowly as the body breaks down the alcohol.

  1. After you are sure that the students understand how to read the tables in Master 5.1, divide the class into teams of three students. Continue to set the stage for the activity by explaining that students will be analyzing BACs for fictitious individuals who attend a party where alcoholic beverages are being served. The task for the students is to determine each individual’s BAC and decide whether the individual can legally drive home.
  2. Ask the class how they will determine whether the individuals are sober enough to drive a car legally.

Students may respond that the BAC measurement is used to determine whether a person is driving while intoxicated. Students also may respond that certain behavioral changes, such as stumbling, loss of coordination, and so forth, would indicate when a person should not drive.

  1. Pass out to each student team a copy of Master 5.2, Drinking Patterns for Party Guests. Explain that the master consists of three pages with data for two different party guests on each page. Each team member should take one page and analyze the data for those two individuals. Explain that they are to use the Blood Alcohol Concentration Tables (Master 5.1) to determine the BAC for each hour that the guest attends the party.

It is a good idea to work through the following example to acquaint the students with the process.

National Science Education Standards icon
Content Standard A:

Mathematics is important in all aspects of scientific inquiry.
  1. During the first hour of the party, a 120-pound female drinks 2 drinks. She has not had any alcohol to drink before the party started, so her BAC at the start of the hour is 0.00.
  2. From the table on Master 5.1, 2 drinks would give her a BAC of 0.08.
  3. Adding 0.08 to 0.00 equals 0.08, which would be recorded in the fifth row of the chart [BAC (start + table)].
  4. Next, subtract 0.02 from 0.08 to account for the body breaking down some of the alcohol.
  5. This means that at the end of the hour the BAC is 0.06. Record this value both as the BAC at the end of hour 1 and also as the BAC at the start of hour 2.
  6. The female drinks 1 drink during the second hour. Again referring to the BAC table, this means that 0.04 is added to her existing 0.06 BAC, yielding 0.10.
  7. Subtracting 0.02 for breakdown during the second hour leaves her with a BAC of 0.08. This process is repeated to obtain the BACs for the next two hours.
This guest is a 120-pound female:
Hour 1 2
Number of drinks 2 1
BAC at start of hour A. 0.00 E. 0.06
BAC from table B. 0.08 0.04
BAC (start + table) C. 0.08 F. 0.10
Alcohol processed D. –0.02 –0.02
BAC at end of hour E. 0.06 G. 0.08
  1. While the students are calculating their party guest’s BACs, pass out to each team a copy of Master 5.3, Blood Alcohol Concentration Graph Template. Ask students to graph their results for each individual for the four-hour duration of the party on the same graph. Students can use a different colored pencil for each individual’s data. Each team member should graph the data that he or she analyzed.

Teacher note
For this activity, students should assume that the legal BAC limit is 0.08 percent. We selected this value because many states have set this as the legal standard. However, if the legal BAC limit in your state is different (0.10 percent, for example), you may use this value instead. This may change the conclusions made for the different individuals portrayed in the activity.

National Science Education Standards icon
Content Standard A:
Communicate scientific procedures and explanations.
  1. After the teams have finished analyzing and graphing their data, ask them to share their results with the class. Display a transparency of Master 5.3, Blood Alcohol Concentration Graph Template, and have different students plot the data for the six different party guests.

The completed charts and graphs for the six party guests are shown below.

Guest 1 is a 120-pound female:
Hour 1 2 3 4
Number of drinks 2 1 1 0
BAC at start of hour 0.00 0.06 0.08 0.10
BAC from table 0.08 0.04 0.04 0.00
BAC (start + table) 0.08 0.10 0.12 0.10
Alcohol broken down –0.02 –0.02 –0.02 –0.02
BAC at end of hour 0.06 0.08 0.10 0.08
Figure 5.3
Figure 5.3.
BAC over time for Guest 1.
Guest 2 is a 180-pound male:
Hour 1 2 3 4
Number of drinks 2 2 1 0
BAC at start of hour 0.00 0.02 0.04 0.04
BAC from table 0.04 0.04 0.02 0.00
BAC (start + table) 0.04 0.06 0.06 0.04
Alcohol broken down –0.02 –0.02 –0.02 –0.02
BAC at end of hour 0.02 0.04 0.04 0.02
Figure 5.4
Figure 5.4.
BAC over time for Guest 2.
Guest 3 is a 160-pound female:
Hour 1 2 3 4
Number of drinks 3 2 0 0
BAC at start of hour 0.00 0.07 0.11 0.09
BAC from table 0.09 0.06 0.00 0.00
BAC (start + table) 0.09 0.13 0.11 0.09
Alcohol broken down –0.02 –0.02 –0.02 –0.02
BAC at end of hour 0.07 0.11 0.09 0.07
Figure 5.5
Figure 5.5.
BAC over time for Guest 3.
Guest 4 is a 160-pound male:
Hour 1 2 3 4
Number of drinks 0 0 3 2
BAC at start of hour 0.00 0.00 0.00 0.05
BAC from table 0.00 0.00 0.07 0.05
BAC (start + table) 0.00 0.00 0.07 0.10
Alcohol broken down 0.00 0.00 –0.02 –0.02
BAC at end of hour 0.00 0.00 0.05 0.08
Figure 5.6
Figure 5.6.
BAC over time for Guest 4.
Guest 5 is a 140-pound male:
Hour 1 2 3 4
Number of drinks 3 2 1 0
BAC at start of hour 0.00 0.06 0.09 0.10
BAC from table 0.08 0.05 0.03 0.00
BAC (start + table) 0.08 0.11 0.12 0.10
Alcohol broken down –0.02 –0.02 –0.02 –0.02
BAC at end of hour 0.06 0.09 0.10 0.08
Figure 5.7
Figure 5.7.
BAC over time for Guest 5.
Guest 6 is a 220-pound male:
Hour 1 2 3 4
Number of drinks 3 2 1 0
BAC at start of hour 0.00 0.03 0.04 0.04
BAC from table 0.05 0.03 0.02 0.00
BAC (start + table) 0.05 0.06 0.06 0.04
Alcohol broken down –0.02 –0.02 –0.02 –0.02
BAC at end of hour 0.03 0.04 0.04 0.02
Figure 5.8
Figure 5.8.
BAC over time for Guest 6.
  1. Conclude the activity by asking students to respond to the following questions.

If the legal BAC limit in the state is 0.08 percent, Guests 2, 3, and 6 would be below the legal limit for intoxication and able to drive home legally. Note that if an individual’s BAC is right at the legal limit (BAC = 0.08 in this case), it is not legal for that individual to drive a car.

Although these individuals could legally drive, they might not be safe drivers. In the following activity, students will learn more about how even low BACs can impair judgment, coordination, and reflexes.

Students should recognize that number of drinks, pattern of drinking, gender, and body weight all influence a person’s BAC.

A larger person has more body water for the alcohol to be distributed in. This means that a given amount of alcohol will reach a lower BAC in a large person than a smaller person.

Females tend to be affected more by a given amount of alcohol than males for two reasons. First, they tend to be smaller than their male counterparts and second, they tend to have more body fat than males do, which has the effect of reducing the amount of body water in which to distribute the alcohol.

A person’s BAC is affected mainly by how much alcohol he or she drinks and over what period of time the drinking occurs. Alcohol metabolism occurs at a constant rate. If the rate of alcohol consumption is faster than the body’s metabolism rate, then the BAC will increase.

Students should notice that in this activity, the BAC always decreases by approximately 0.02 percent per hour for all individuals. In reality, metabolism rates can vary somewhat among individuals. The important point here is that when a person drinks alcohol, it is broken down at a constant rate, regardless of how quickly or slowly the person drinks.

The guests attending the party in this activity would not have access to information about their BACs. Therefore, it is likely that some of them would have judged themselves fit to drive, even though their BAC exceeded the legal limit.

Student responses will vary. Accept all reasonable responses and list them on the board. Direct their attention to factors such as the amount and type of food in the stomach, body type (amount of body fat), and genetic factors.

  1. Ask students to keep their copies of Masters 5.1 and 5.2 for use in the next activity.

Optional Activity

National Science Education Standards icon
Content Standard A:
Identify questions that can be answered through scientific investigation.

Content Standard A:
Design and conduct a scientific investigation.

assessment icon
Assessment:
This part of the activity enables you to assess students’ abilities to identify questions that can be answered through scientific investigation. It also provides assessment opportunities relating to methods of analysis and drawing of conclusions.
  1. Give students an opportunity to ask their own questions about how an individual’s BAC is affected by drinking alcohol. For convenience, students can work in their same teams to decide on a question they want to investigate. Remind students to ask a question that can be answered given the information found in Masters 5.1 and 5.2. Some questions that students may investigate include the following:

Asking an appropriate question might be difficult for some students. Explain that they should try to keep all variables constant, except for the one that they are investigating. Circulate around the room and ask them to explain how they are answering their question. If they have difficulty making proper comparisons, guide them with questions that will help them refine their question or the way they are conducting their analysis.

  1. After teams finish analyzing their question, ask them to present their results to the class. Encourage each member of the class to participate in the presentation by discussing a specific aspect of the work, such as framing the question, performing the calculations, or stating the conclusions. Ask other members of the class if they agree or disagree with the conclusions.

Activity 2: Alcohol and Driving Behavior

Web activity iconThis activity requires the use of computers with access to the Internet and a sound card. If this is not possible, give each student team a copy of Master 5.4, Progressive Effects of Alcohol, and proceed with this activity starting with Step 8.

  1. Introduce the activity by explaining to the class that they will watch two brief driving simulations. The simulations show the view as the driver would see things.
  2. Divide the class into teams of two to three students who will work at one computer. Log onto the Web site http://science.education.nih.gov/supplements/alcohol/student and click on “Lesson 5—Alcohol and Driving: When to Say No.”

Teacher note
This activity is designed for students to work at a computer in small teams. This approach stimulates interaction and discussion among students. You may, however, need to modify the size of the groups depending on the number of computers available. For alternate strategies, see Using the Web Site.

  1. Instruct students to watch Simulation A and Simulation B and to record the differences they observe between the two drivers.

Students will not know at the beginning which simulation represents which driver. However, they should record their observations about each simulation. Students may need to watch each simulation a few times.

National Science Education Standards icon
Content Standard A:

Think critically and logically to make the relationships between evidence and explanations.
  1. After students have viewed the simulations and recorded their observations, discuss their findings and record their observations on the board. The major differences are listed below:
Simulation A (intoxicated) Simulation B (sober)
Staggers while walking to car Walks in a straight line to car
Has blurred vision Has clear vision
Does not look both ways before crossing the street Looks both ways before crossing the street
Does not fasten seat belt Does fasten seat belt
Has trouble putting key in ignition Puts key in ignition easily
Exceeds speed limit Does not exceed speed limit
Does not always stay in correct lane Stays in correct lane
Drives using one hand Drives using both hands
Runs through stop signs Stops smoothly at stop signs
Does not stop for pedestrian Stops to allow pedestrian to cross street
Does not use turn signals Does use turn signals
Hits the trash can in driveway Parks car without hitting trash can

Students may notice other minor differences, but the ones listed above are the primary ones.

  1. One simulation portrays a sober driver and the other portrays an intoxicated driver. Ask students which simulation shows the intoxicated individual.

Students will respond correctly that Simulation A shows the intoxicated driver.

  1. Ask students what they think the BAC of the driver in Simulation A was. Display a transparency of Master 5.4, Progressive Effects of Alcohol. This chart depicts the escalating impairments that happen as increasing amounts of alcohol are consumed. Explain that impairments associated with low BACs still apply at higher BACs.
  2. Ask students to provide reasons for their BAC estimates.

Students should estimate a BAC for the intoxicated driver based on information in Master 5.4 and on what they observed in the simulation. Because students know that the driver is intoxicated, they will estimate BACs of 0.08 and higher. Students might say that the BAC could be as high as 0.21 to 0.30 because the person staggered when walking. If the BAC is in this range, in addition to the more severe impairments of reaction time and lack of balance, the driver would also display impaired alertness, judgment, depth perception, reasoning skills, and coordination. Each of these impairments would make this person a hazardous driver.

  1. Ask students to get out their copies of Master 5.2, Drinking Patterns for Party Guests, from Activity 1 in this lesson. Ask them to examine the data for each of the party guests they evaluated. Using Master 5.4, Progressive Effects of Alcohol, instruct the class to estimate how each individual’s BAC would affect his or her ability to drive a car. Revisit the question of whether or not each individual should drive home. Students can write their responses on the back of Master 5.2.

Students should compare the BAC of each individual with the table. They should list activities that are impaired in individuals who have a BAC in that range.

You will notice that the chart on Master 5.4 is depicted as a continuum and that there are no distinct cut-off points between impairments at adjacent BAC ranges. This is intended to convey the idea that impairments exist in varying degrees as opposed to simply being present or absent. This depiction is also consistent with human variation; that is, two people may be affected slightly differently from each other at a given BAC.

  1. Give students the opportunity to share with the class their conclusions about each of the party guests and the impairments that would affect their driving.
assessment icon
Assessment:

If you wish to use question 9 as a more formal opportunity to evaluate students’ understanding, ask them to write their answers to this question. You may then review the responses from each student. Asking students to write their answers before sharing them with the class allows them to organize their thoughts and reflect on what they have learned.

Guest 1 has a BAC of 0.08 at the end of the party. Students may respond that she should exhibit impairments in alertness, judgment, depth perception, and visual tracking. Most will agree that she should not be behind the wheel.

Guest 2 has a BAC of 0.04 at the end of the party. Students may respond that even though he has a BAC below the legal limit for driving, he is still affected by the alcohol. He may be less alert and less coordinated and make poorer judgments than if he hadn’t drunk any alcohol.

Similar types of observations can be made for the other four party guests. Some students may conclude that it may not be a good idea for any of the party guests to drive a car.

  1. Ask students to consider the question, Does a BAC below the legal limit mean that it is safe for an individual to drive a car?

Even though some individuals have BACs that are below the legal limit for driving, it may not be safe for them to operate a car. This is an important point for students to understand. A BAC below the legal limit does not mean that a person’s mental and physical skills are not impaired. In fact, there is no one particular BAC where hazardous driving begins. Even one drink can cause impairment. This helps explain why different states and different countries set different legal limits for drinking and driving.


Lesson 5 Organizer
Activity 1: Patterns of Drinking
What the Teacher Does Procedure Reference
Ask the class if two people attend a party and drink the same amount of alcohol, will they be affected in the same way? Step 1

Ask students to recall information they learned in previous lessons.

  • What factors influence how different people respond to alcohol?
  • Where does alcohol go in the body?
  • Where is alcohol broken down?
Step 2

Help the class understand how to use Master 5.1, Blood Alcohol Concentration Tables.

  • Make sure that the students understand how metabolism reduces BACs.

master iconSteps 3 and 4


transparency icon

Divide the class into teams and make sure they know how to

  • determine BAC levels for fictitious individuals attending a party.
  • determine if those individuals can legally drive a car.
Steps 5 and 6
Pass out to each team a copy of Master 5.2, Drinking Patterns for Party Guests. master iconStep 7
Have students graph the BACs over time for each guest using Master 5.3, Blood Alcohol Concentration Graph Template. master iconStep 8
Have student teams share their results with the class using a transparency of Master 5.3, Blood Alcohol Concentration Graph Template. transparency iconStep 9

Summarize results from the activity. Ask the class,

  • Which individuals could drive home legally?
  • What factors affected the party guests’ BAC levels?
  • Why is a larger person affected less by a given amount of alcohol than a smaller person?
  • Why are females more affected by drinking the same amount of alcohol as males?
  • How does the pattern of drinking relate to an individual’s BAC?
  • Are there differences in how fast alcohol breaks down in the body among different individuals?
  • Do you think that the individuals whose behavior was modeled in this activity would have reached the same conclusions as you did about who should drive from the party?
  • Are there factors not taken into account during this activity that could influence an individual’s BAC?
Step 10
Instruct students to keep their copies of Masters 5.1 and 5.2 for use in the next activity.
Step 11
Activity 2: Alcohol and Driving Behavior
What the Teacher Does Procedure Reference
Explain to the class that they will watch two short driving simulations. Step 1
Divide the class into student teams and have them log onto the Web site. Have the students click on “Lesson 5—Alcohol and Driving: When to Say No.” Web activity iconStep 2
Instruct students to watch each simulation and record their observations. Step 3
Reconvene the class, discuss the students’ findings, and record their observations on the board. Step 4
Ask the students which simulation portrayed the intoxicated driver. Step 5
Display a transparency of Master 5.4, Progressive Effects of Alcohol, give each team a copy, and ask the class to estimate the BAC of the intoxicated driver.

transparency iconSteps 6 and 7

master icon

Have students retrieve their results from Activity 1 and ask them to consider how alcohol impaired each of the party guests. Step 8
Have students share their conclusions with the class. Step 9
Discuss whether a BAC below the legal limit means that it is safe for an individual to drive a car. Step 10
transparency icon= Involves using a transparency.  
Web activity icon= Involves using the Internet.  
master icon= Involves copying a master.  

Return to Lesson Plans