Not to be too cynical about it, but February is a good month for playing with fire, from a TV-ratings point of view.It's another Nielsen "sweep" month, which means the ratings service takes broader audience measurements. The results of these ratings help determine ad rates for months to come.

And so local stations suddenly find it imperative to investigate massage parlors and sex clinics and all manner of guaranteed attention-grabberss for their profitable local newscasts. However, the CBS televisions network may have gone everybody else one better -- or one worse, depending on your point of view -- with "Fallen Angel," a TV movie about a 13-year-old girl who is lured into the child porno trade. It airs tonight at 9 p.m. on Channel 9.

Lew Hunter, writer and producer of the film, composed a statement defending the film, maintaining that "child pornography is the symptom and not the real disease" and that "the disease" has to do with "the lack of responsible adult-child relations in America today." The film ends with a lecture on this topic delivered by the actress playing the attorney who prosecutes the pornographer.

So much for the redeeming social value. What precedes it, in the film, treads precariously along the border between sobering expose and titillating exploitation of what is allegedly being exposed -- the turning of tots into sex objects.

Richard Masur plays the pedophile who procures children for a porno filmmaker; the script establishes that the character, called Howard, is not evil but "sick." He doesn't force the children into the eye of the camera; he finds disaffected youths who feel ignored and then showers them with love and attention.

In the film, Dana Hill plays his latest victim, the just-turned-13 daughter of a widowed mother who works split shifts as a waitress at a coffee shop. The child is still suffering from the loss of her father, and she dislikes mom's new boyfriend. Along comes a spiker brandishing not candy but a Polaroid camera, and telling her she's "sexy" and looks like Raquel Welch.

His opening lines are suggestively colored; "You look exactly like someone who's havin' fun and wants to have some more," he tells her when they meet at a pinball parlor. Later: "You should really be in movies" and, "Did you ever want to be a movie star?"

The flirtation continues. In one picture, the girl is licking an ice cream cone. "I look like an anteater," she says when he shows her the photo. "Never wanted to be an ant. Till now," he responds.

He gives her a teddy bear. They go to a park for more pictures. He shows her a porno magazine. ("Yuck!" she says.) "Let's try some shots without your clothes on," he says. Soon he is photographing her with a young boy in their bathing suits. "For this one, we need the suits off," he tells them. i"But it's wrong," she says. But soon enough she has put down her bottle of orange soda pop and removed her suit.

"Good. Great. Perfect," he says.

Obviously, when you depict a seduction like this on the screen, you are going to provide a kind of pornography for a kind of viewer. The film is careful to shoot the young actress only from the shoulders up when she is supposed to be naked or semi-clad. And a spokesman from Columbia Pictures Television, which made the film, says actress Hill is 16, even though she looks much younger, and was thus able to handle the part emotionally.

Producer Hunter says from Hollywood, "A police officer here told me this will become a cult film in the pedophiliac community. I feel very badly about it, but it's a ramification you have to deal with. I feel like a doctor performing an operation; in order to cure 'this' you have to create 'that.'"

Hunter says he also feels like a "carnival barker" luring people into the tent with the sensational subject of child pornography when the film is really about a deeper problem. "Once they get in the tent, they hopefully will perceive a message that will be effective to them and have influence on their lives," he says.

Should children see this film? "I definitely think so," says Hunter. "They should see it with a responsible adult, with their parents. A psychiatrist I know who's seen the film was so moved by it she's going to have a number of kids and adults over to her house to watch it when it's on the air and discuss it afterwards."

Hunter concedes CBS may have scheduled the film during the sweeps because of its hot topic. But he also thinks there are network executives who had "humanistic" reasons for wanting the film made; that it could do some good. "We're all interested in getting a 40 share to get as many people as possible to be aware of this social problem," he says, "so the film can have an afterlife, rather than just knock off ABC and NBC on Tuesday night."

Rep. Robert Dornan (R-Calif.) screened the film in his Capitol Hill office recently. An aide says he is interested in the problem of child abuse. oHunter says he hopes his film will be influential in getting tougher laws passed for child molesters.

It all sounds worthy enough, but we can't discount the possibility that America might not have the sexual problems it has if television weren't so frequently peddling sex to sell goods in the first place. "Fallen Angel" may simply get lost in a month full of panting and pandering on the air.