It is a perilous time to be a celebrity. Danger lurks in every issue of People magazine and drips from every headline in the Star.

The 20th century did not invent salaciousness or even improve on it. Gossip is an eternal medium and the appetite for it is ageless.

But we have made a dubious contribution. There was a time when gossip was relegated to newspaper columns adorned with provocatively italicized items, as in "Item: What female screen star is dating a man young enough to be her son?" Silly, harmless stuff.

But gossip has changed. Perhaps it was the inevitable consequence of Watergate and the zealous reporting of everything including gossip. Historians of the genre will remember this as the era when the people's hunger to know (which female star is dating a man young enough to be her son) became inextricably wedded to the people's right to know.

The result is a new type of gossip -- crusading instead of merely wicked, portentous instead of just plain fun. The result is Jason Bonderoff's shameless biography "Mary Tyler Moore," a book that is as insipid as it is insidious.

It takes Bonderoff 191 pedestrian pages to chronicle the proverbial ups and downs of Moore's career, the sad facts of what he calls her "real life." The divorces, the diabetes, the tragic death of her only child, Richard Meeker Jr., her marriage to (gasp!) a younger man. The result is worse than vicious, it is self-righteous. The facts, the questions, the rumors are all laid out in the name of completeness and objectivity.

What makes this book particularly appalling is that Bonderoff pretends to care. He salutes her courage and her pluck. After the second paragraph, we are all on a first-name basis, as in: "Mary, to most of us, was still the perfect all-American girl."

Nastiness lies just below the the sugary surface. The heart of the book -- and that word is used advisedly -- is the absurd modern tautology that the character portrayed on the screen must be a reflection of the person doing the portraying. To wit: "Mary Tyler Moore and her on-screen counterpart had blended into one eternally happy Girl Scout."

The all-American girl. "We think of her forever serene and cool, with her back, like the crease in her tennis whites and the stitches of her needlepoint, perfectly straight," Bonderoff intones solemnly.

He records every deviation from that glistening image as if it were a revelation or worse, a betrayal.

Dutifully, he reports her smoking, her drinking, her aloofness from colleagues. Unlike Mary Richards, Mary Tyler Moore apparently had no Rhoda Morgenstern. She was never comfortable enough to confide her sorrows to the neighborhood women who joined her every afternoon for aerobics (as if that would be an appropriate forum for such a discussion).

At times, the relentless comparisons between Mary Tyler Moore and her on-screen personas -- Mary Richards, Laura Petrie, Beth Jarrett, et al. -- are downright surreal. At other times, they are merely offensive. Sometimes they are both.

Take the description of her wedding to Robert Levine, the younger man, whom Bonderoff notes pointedly and tastelessly was only a few years older than her son Richie would have been had he lived.

"Let's face it, who could ever have imagined goyishe Mary -- no matter how good a sport she was -- standing under a chupah (Jewish wedding canopy) while the groom nervously smashed a wine glass with his foot and guests shouted, 'Mazel tov!' Rhoda Morgenstern should have been the bride, not Mary."

Graciously, Bonderoff concedes that "their devotion was surprisingly real" considering they weren't "the typical bride and groom on the wedding cake."

After a while, Bonderoff's insistence upon drawing parallels between her roles and her life degenerates into the macabre, particularly in discussing the death of her son. Early on, Bonderoff points out that unlike Laura Petrie, the perky homemaker of the Dick Van Dyke show, Mary Tyler Moore was not content to stay home and raise her son. "Yet no one would deny Mary loved her son deeply," he writes, thereby raising a suggestion offensive to all working women. Then he tries to make amends. "Was it coincidence that Laura Petrie's son on The Dick Van Dyke Show was named Richie? Or that Mary chose Richards as her character's name on the Mary Tyler Moore Show? Probably not. Although she may have been an absentee parent much of the time, Mary was trying very hard to send Richie signals that he was still important in her life."

In 1980, the year Moore starred as Beth Jarrett, the mother of a suicidal son in "Ordinary People," her son died of an accidental, self-inflicted bullet wound. "Interestingly enough," Bonderoff notes parenthetically, "although Mary's relationship with her own son, Richie, was a troubled one, she saw no parallels between Beth and herself as mothers."

Despite the coroner's report that Richard Meeker's death was accidental, Bonderoff leaves plenty of room for speculation. His account is drawn from reports in the National Enquirer, the Star, People magazine and the Los Angeles Times. This is what is known in the trade as a clip job. He loses whatever credibility he had when he quotes the Enquirer: "Mary Tyler Moore was too busy being America's sweetheart to be a mother to her only son Richard -- and give him the love he desperately craved."

Bonderoff's book is a clip job in more ways than one. Undoubtedly, the recent debut of Mary Tyler Moore's new show "Mary" made this an enticing and timely addition to St. Martin's list. In truth, no time was the right time to publish this book.