When the subject is smoking in the office, few people are neutral. One government unit at the National Cancer Institute has banned it. Most government buildings have no-smoking areas. But enforcement varies from agency to agency.

When he was secretary of Health and Human Services, Joseph Califano (himself a reformed smoker) made it clear -- to staffers and visitors -- that he didn't appreciate that kind of air pollution in his office.

Former postmaster general E.T. Klassen cured an aide of a 30-year smoking habit by giving him a choice: Stop smoking at the office or stop coming to the office.

On the other hand, Office of Personnel Management Director Donald J. Devine, who enjoys a good cigar, has been known to light up even under the "No Smoking" sign in OPM's auditorium.

Attitudes, like we said, vary.

Today's first Monday Morning Quarterback comment comes from a fed who says Uncle Sam ought to snuff out smoking in public buildings. On another matter, the second is from a former federal couple who think the government is on a self-destruct course. Here goes:

* "Some time ago you reported that the government could, in certain situations, purchase air purifiers to protect employes and the public from smoke in federal offices.

"While I was delighted to read it, it seems to me this represents a costly attempt by the government to dance around a serious problem.

"Wouldn't it be wiser and less expensive if the government simply banned smoking in its buildings? I see no reason why the taxpayers should subsidize air purifiers for federal offices when a more positive solution is available.

"Would you ask your readers, smokers and nonsmokers, to comment on this proposal? There may be some good reason for allowing people to smoke in public buildings, however I have never heard it." -- A.M., Bethesda.

* "We are a couple in our late sixties, both retired government workers. One of us joined the government in the 1930s, and our home town (Michigan) paper reported the appointment to a minor job with the FBI. One of us joined the military during World War II. One worked in the Army property division.

"In following years we worked in both government and industry . . . and viewed our years of federal service as the most satisfactory, not because of monetary rewards but because of the public service and the firm guarantee of our future security . . . through the retirement system.

"Now for the first time in nearly 50 years we feel a sense of betrayal as the administration orchestrates its attack on federal employes and retirees. The thinly disguised implication underlying this attack is that these people -- in our experience typically hard-working and loyal -- are unworthy, unproductive and overpaid.

" . . . We are told that to solve the monumental budget deficit problem federal workers and retirees must 'share the sacrifice.' In effect they are being asked to accept a tax increase -- a special one for them only. If the budget deficit is truly a national problem, why should not all citizens contribute through a tax increase?

"If the bargain with federal workers and retirees is not kept . . . for a shortsighted 'quick fix' the public will be the longtime loser. The quality of essential government services will inevitably decline as workers become disillusioned and the best of them depart for private sector jobs while young job entrants shun public service." -- Mr. and Mrs. F.D., Washington.