SALVADOR, BRAZIL

Jose Romulo Silva Santos, a Brazilian policemen, warily eyed his instructor, who was running down a list of social and economic problems that turn children to prostitution.

"What should I do if I see them stealing or killing somebody?" he asked the instructor. "Be nice to them? What they need is a sound thrashing."

But at the end of the three-week course in July, Mr. Santos' skepticism had turned to sympathy. With tears in his eyes, he told a group of fellow officers: "Now I get angry when I see adults with these kids."

Mr. Santos is one of 60 policemen from the northern Brazilian state of Bahia who recently participated in a human rights course sponsored by the Center of Defense of Children and Adolescents (CEDECA), a nongovernmental organization here.

The class is part of a public-awareness campaign, begun in 1995 by CEDECA and funded by UNICEF, to end child sexual exploitation. "There is no doubt that people are beginning to change," says Helia Barbosa, CEDECA's executive director. "We have awakened many here."

Ms. Barbosa, however, acknowledges that changing society's attitudes about child sex exploitation and especially teen prostitutes has been an uphill struggle. Many Brazilians see nothing wrong with adult males having sex with young girls, a practice that has been widespread since Portuguese explorers cohabited with young Indian girls. Child prostitutes are typically seen as being "shameless" and involved in prostitution because "they like it," according to Barbosa.

"Before this campaign, it was a nonissue," says Agop Kayayan, Brazil's UNICEF representative. "If someone said he went to bed with an 11-year-old, the typical response wasn't 'how could you?' but 'how was it?' " In a recent publicity campaign for the Brazil edition of Playboy magazine, billboards highlighted the month's playmate, a young soap opera star, with the caption: "She may be 18 but she has the body of a 15-year-old." Last summer, an ad in a newspaper for a Porto Alegre nightclub read: "Now that your wife and children have been packed off to the beach, it's time for you to play with other peoples' children."

According to a 1994 investigation on child prostitution by a special commission of the Chamber of Deputies, Brazil's lower house, prostitutes were found to be as young as five years old. "There exists the distorted view that the relationship with child prostitutes is an affirmation of youth and masculinity," said the report.

From CEDECA's command post above a fishermen's supply store facing Salvador's historic port, Barbosa and her 10-member staff are busy organizing debates, speeches, seminars, and meetings with students, unions, lawyers, politicians, and police officials.

Barbosa is happy about CEDECA's new agreement to work with the Salvador police, an institution known for harassing child prostitutes with beatings and demanding sexual favors.

"We [police] have long been part of the problem," concedes Police Maj. Gautier Amorim Neto. "Now, we want to be part of the solution."

Major Amorim hopes the human rights classes will "awaken my men's inner sensibilities. We are trained to be belligerent warriors with no orientation regarding the country's socioeconomic problems," he adds.

CEDECA is also working closely with truckers' unions that have promised to punish drivers who commonly transport young girls from city to city in exchange for sex.

The key to CEDECA's success has been its "ability to create partnerships with traditional child sex-exploiters," says Cesare de Florio La Rocca, director of Projeto Axé, a respected nongovernmental organization that works with Salvador's street children.

According to Barbosa, the campaign initially focuses on making society aware of the socio-economic problems that drive most children into prostitution such as poverty, domestic violence, and sexual abuse by a relative. This is followed by an appeal to denounce adults who exploit them.

During last year's carnival, when hundreds of thousands of Brazilian and foreign tourists invaded the city, CEDECA volunteers passed out pamphlets warning visitors: "Sexual exploitation of children is a crime and can lead to imprisonment." Posters were pasted on walls showing images such as a lone man behind bars under the caption: "There are many rooms for those who exploit minors."

The campaign's major publicity boost, however, came from three of Brazil's most famous samba singers. In a television and radio blitz, superstars Caetano Veloso, Gilberto Gil, and Daniela Mercury told a nationwide audience that "if you keep quiet, you consent. Denounce child sexual exploitation now." A hot-line number then flashed across the screen.

As a result, there have been 3,343 denunciations and 204 police investigations, in which 113 cases were turned over to state prosecutors, according to Bahia police records. Three CEDECA attorneys follow up investigations and offer free services to parents of exploited children.

"The CEDECA campaign has quadrupled my work," says Regina Sampaio, police chief of the special Division of Protection of Children and Adolescents in Salvador. "Before, we never received any complaints about child prostitution."

In a nation where sex crimes against children rarely result in an investigation, the hot line has led to several arrests, including a man selling child pornography, three fathers who raped their daughters, and two brothel owners, who placed teen prostitutes in a brothel picture window to attract customers.

Most important, the campaign has provoked a fierce debate over the Brazilian justice system and the reluctance of many judges to prosecute adults who have sex with minors.

Last May, for example, Supreme Court Judge Marco Aurélio de Mello wrote the opinion in a 3 to 2 decision to release Márcio Luiz de Carvalho, a house plumber sentenced to six years in jail for raping a 12-year-old girl. In his summation, Judge de Mello argued that the girl had consented to having sex, had lived a "promiscuous life," and that "in these times, there aren't little girls, but young women of 12 years, precociously mature."

Despite such views, CEDECA members say some judges are getting their message and point to a landmark decision by Judge Afrânio de Andrade Machado, a magistrate from the Bahian coastal city of Caravelas. In May, he shocked many here when he condemned 15 of the city's leading businessmen to prison terms of eight to 24 years for the 1992 sexual abuse of two girls, aged 9 and 13.

Other CEDECA victories include:

* The Salvador City Council has passed laws making sex education a required subject in public schools and banning minors from motels, hotels, and nightclubs without parental supervision.

* An eight-member police team has been created to investigate hot-line accusations.

* A special court is being planned to prosecute child sex exploiters.

* CEDECA plans to sign an agreement this month with the police department and Salvador tourist associations to require hotels, restaurants, and bars to place signs in several languages warning tourists about having sex with minors.

These results have caught the eye of Brazilian President Fernando Henrique Cardoso, who last year asked the Justice Ministry to launch a similar nationwide program, including the establishment of a national hot-line number. "We are reversing a centuries-old practice," says Arlinda Uzêda, a CEDECA attorney. "It may seem like a drop in a bucket, but the drops are increasing."

In this seaside resort city in northeastern Brazil, teenage girls who sell themselves to foreign "sex tourists" often do so for a surprising reason.

Some 75 percent, according to a 1993-95 survey of the girls by a group known as Woman's Life Collective, entered the sex trade to marry a "European Prince Charming" who would change their lives. Another 55 percent said that they had traveled to Europe with the men who had paid them for sex.

After finding that most sex tourists in Recife were German, the collective - in conjunction with German activist groups - helped end weekly flights of a German air-charter company that had catered to the sex trade. And Germany outlawed sexual relations between its citizens and minors under 16 anywhere in the world.

Brazil's government, worried about the nation's image overseas, has joined the campaign. In recent months, Justice Ministry officials have met with Brazilian airline and tourist groups, asking them to denounce travel agents who sell sex tours. Caio Luiz de Carvalho, the president of Embratur, the government tourist bureau, warned state governments that promote sex tourism that they will have their federal monies suspended. And Brazil appealed to Germany, Italy, France, and Argentina to clamp down on similar agents in their countries.