There are three major forms of beverages containing alcohol (ethanol) that are regularly consumed. Wine is made from fermentation of fruits and usually contains up to 14 percent of ethanol by volume. Beer is brewed from grains and hops and contains 3 to 6 percent ethanol. Liquor (whisky, gin, vodka, and other distilled spirits) is usually 40 percent (80 proof) to 50 percent (100 proof) ethanol.
A bottle of beer (12 ounces), a glass of wine (4 ounces), and a cocktail or mixed drink with a shot of whiskey in it, therefore, each have about the same absolute alcohol content, one-half to three fourths of an ounce of ethanol. Alcohol is a central nervous system depressant, and its physiological effects are a direct function of the percentage of alcohol concentrated in the body’s total blood volume (which is determined mainly by the person’s body weight).
This concentration is usually referred to as the BAC (blood alcohol content) or BAL (blood alcohol level). A 150-pound man can consume one alcoholic drink (about three-fourths of an ounce) every hour essentially without physiological effect. The BAC increases with each additional drink during that same time, and the intoxicating effects of alcohol will become noticeable. If he has four drinks in an hour, he will have an alcohol blood content of
10 percent, enough for recognizable motor-skills impairment. In almost all states, operating a motor vehicle with a BAC between .08 percent and .10 percent (determined by breathalyzer or blood test) is a crime and is subject to arrest on a charge of DWI (driving while intoxicated). At .25 percent BAC (about ten drinks in an hour) the person is extremely drunk, and at .40 percent BAC the person loses consciousness.
Excessive drinking of alcohol over time is associated with numerous health problems. Cirrhosis of the liver, hepatitis, heart disease, high blood pressure, brain dysfunction, neurological disorders, sexual and reproductive dysfunction, low blood sugar, and cancer, are among the illnesses attributed to alcohol abuse (National Institute on Alcohol Abuse and Alcoholism 1981, 1987; Royce 1990; Ray and Ksir 1999).