At the age of 15, Robby Morris starts the day with a chew of Levi Garrett.

Wadding a golfball-size chunk of the chewing tobacco, he deftly places it between gum and cheek. A speck of brown clings to the peach fuzz on his upper lip.

"I have my first chew before breakfast," he says. "Sometimes I chew in the shower and spit down the drain. Then I have another walking to the bus stop, then one around 11 at school with the other kids, and one before football practice."

Morris, a sandy-haired sophomore at Annandale High School, started chewing tobacco in the fifth grade. Two years ago he went to a doctor complaining of sharp pains in his stomach. "The doctor told me to quit chewing for a while," he says. "I was chewing more than I was eating."

Now, with sepia-stained teeth as evidence, Robby Morris chews a pack of the brown, bitter tasting tobacco each day because, he says, "It's cool."

Chewing tobacco and "dipping" snuff is the latest craze among suburban teen-aged boys. Eager to emulate the urban cowboy, the macho image of baseball players, sports superstars and rock groups who currently are plugging the products, the predominantly white, middle-class teen-agers say a swollen cheek is the ultimate in "redneck chic."

"It's definitely a status symbol," says one parent, whose 14-year-old son "dips" snuff. "They're all doing it."

There is another side to the fad, however. As sales of smokeless tobacco soar -- thanks in part to youth-oriented advertising campaigns using such celebrities as former Dallas Cowboy star Walt Garrison, Kansas City Royals third baseman George Brett and rock singer Charlie Daniels -- health professionals are becoming increasingly alarmed. They cite long-term hazards of gum disease, tooth abrasion and mouth cancer, as well as short-term effects that chewing and "dipping" may have, especially on teen-agers.

The American Cancer Society is planning a nationwide educational effort, directed to high school and junior high school students, on the dangers of the once-rural pastime, which is becoming increasingly popular in large urban areas.

In the meantime, school officials -- and some students -- are mainly concerned with what happens when the tobacco juices are expectorated.

"You find it all over the floors, the rugs, in the lockers, on the mirrors," said John Schaefer, a 15-year-old sophomore at South Lakes High School in Reston. "It's really gross."

"It's a real problem," says Don Henretty, athletic director of Annandale High School, where every morning more than two dozen students gather outside the school building between classes to chew, dip and spit.

"It's a constant battle to keep it out of the water fountains and the shower rooms. "It's in the lockers, even on the walls," Henretty says.

The penalty for indulging inside the school building is suspension, he says. "But you have to have the evidence in your hand. Usually what we see is the result."

Although all high schools in the area forbid chewing and dipping inside the buildings, the students carry Styrofoam cups, makeshift spittoons of rolled up notepaper and empty milk carton cuspidors to class where the tobacco juices are deposited.

"You're not supposed to chew in school," says 16-year-old Joe Cody, a junior at Herndon High School. "But everybody does it."

"I didn't make a big deal about it until the kids started going into the classroom with cups," says Don Miller, football coach at Langley High School in McLean. "Then they'd leave the cups on the floor and somebody would kick it over. I told them no more."

The other day, an announcement came over the intercom at Bethesda's Walt Whitman High School that anyone caught chewing or dipping in the school would be suspended. Students say they are planning to petition the rule. "It's not fair," says Jack Alexander. "At least we're not smoking."

Richard Gordy, a 15-year-old Annandale student who says he has been chewing tobacco since the age of 10, says, "It tastes good and it relaxes you. My mom thinks it's a bad habit, but my dad doesn't care. I guess he figures it's better than smoking cigarettes."

The girls, he said, don't chew. "Some of them try to grab it from your mouth. Most of the time, they won't talk to you if you're chewing."

As a measure of their devotion, students from Annandale were driving to West Virginia to buy Hawken, which was not yet available in this area. Some mix it with bubblegum, for a sweeter flavor. Novices sometime swallow it and become sick. The habit, however, is fairly inexpensive, most brands selling for between 59 and 79 cents a tin, or pack.

The fad started two years ago, students and administrators say, with the school athletes. In many cases, they were following the example of baseball and football coaches, who were never without a wad in their cheeks. o

"I used to be the only one around here who chewed," said Peter Menke, basketball coach at Bethesday-Chevy Chase High School. "Now, a lot of them [students] do it. It's definitely on the increase. But I'd say it's more snuff here than tobacco."

"I would imagine they've seen the advertisements on television. They see the athletes in baseball games. That had an influence on them, too," said Tom Secules, South Lakes High School football coach who has chewed "on and off" for the last 10 years.

"When the World Series was on," said Wayne Boor, athletic director of Wheaton High School, "they [the students] all thought they were George Brett."

A wad -- or chew -- of tobacco or a pinch of snuff is placed between the cheek and gum, causing a slight burning sensation. When the tobacco juices are released, the bitter-tasting saliva must be expectorated.

A spokesman for a local tobacco wholesaler says that two years ago he was selling two dozen packages of Levi Garrett a month. Now, he is supplying drug stores, grocery chains and convenience stores with 700 dozen packages a week.

Sales of smokeless tobacco have grown at a rate of 7 percent annually, according to the Department of Agriculture. In 1979, 125 million pounds of snuff and chewing tobacco were sold, topping a 30-year sales record broken in 1978. Last year's sales amounted to $400 million, with more than 22 million Americans indulging in the habit. It is, company spokesmen say, the only growth area in the tobacco industry.

"People find it consistent with their life style," says Gerry Gilmartin, executive director of the Smokeless Tobacco Council in Peekskill, N.Y. "It's taken without a good deal of fuss and bother and it's less expensive than cigarettes."

Other industry spokesmen cite the increasing restrictions on cigarette smoking in public places.

Although Gerry Gilmartin says "our product is advertised by adults for adults," the smokeless tobacco message is filtering down to adolescents by way of advertising and promotional items such as belt buckles, bumper stickers and T-shirts.

Ralph Ring, vice president of sales for Pinkerton Tobacco Co., which markets Red Man chewing tobacco, says the use of superstars to promote the product "could have an image effect" on teen-agers. "I would say the ads are having an effect. No question about it," he says.

The U.S. Tobacco Co., which markets Skoal snuff, recently placed an ad in a national magazine featuring former Cowboy Garrison answering questions about smokeless tobacco. "Learning," Garrison says, "is part of the fun," and in two weeks you'll be "a pro."

Dr. Alan Blum, a Chicago physician, says the advertising "is extremely dangerous to the psyche" of teen-aged boys.

"The language of the ads are sort of puberty right," Blum says. "This is a way to start yourself off as a man."

Writing in a recent issue of the Journal of the American Medical Association, Blum said a recently completed study of the effects of smokeless tobacco linked snuff with gum disease, tooth abrasion and white patches on the inside of the mouth known as leukoplakia, considered to be a pre-cancerous condition. Blum also said chewing tobacco can lead to cancer of the mouth, throat and digestive tract.

According to the 1979 Surgeon General's Report, cancer of the esophagus also is related to chewing tobacco.

Blum is even more concerned with the short-term effects that chewing tobacco and dipping snuff may have on teen-agers.

"It's the immediate danger of the habit of ingesting a sugar-laden product which may be the first step toward using other tobacco products, or even other drugs," he said.

Asked if chewing and dipping is addictive, many teen-agers said it was. "Definitely," says Cody. "It's nicotine. And it gets to be part of a routine."

One fed-up football coach in the area has decided to do something about helping his players kick the habit.

"Last year, at the end of the season I went around and found lockers coated with tobacco juice," said Loran Wood of Fairfax High School. "This year, I made them a deal. You chew, you turn in your uniform."

So far, he said, no uniforms have been turned in. . .