Citizens' groups launch a campaign to help put a shine on the Big Apple

The next time you're in New York, don't expect city streets to look like the polished floors of Bloomingdales. But throughout the city a visible effort is being made to sweep streets, get garbage out of gutters, and crack down on litterbugs.

''Where I work, near Penn Station, it seems the streets are dirtier than ever ,'' says Nancy Devitt of the Citizens Committee of New York, one of a handful of nonprofit groups working together to help clean up New York. ''But uptown, where I live, the streets are a lot cleaner and in general there certainly is a much bigger effort to keep the city clean.''

In fact, a recent study of city sanitation by the Mayor's Office of Operations (the city's watchdog agency) concluded that New York City streets are now 13 percent cleaner than they were 18 months ago. The agency makes periodic checks throughout the city to judge whether they are ''acceptably clean.''

But critics point out that a 13 percent improvement, while a significant step in the right direction, still leaves many parts of the city all too littered. And even the most active cleanup advocates admit that many parts of New York are still terribly dirty.

Four months ago an organization called ''We Care About New York'' was formed. Its primary goal: to make New York - from Times Square to Coney Island - a much cleaner place. But the nonprofit group, funded entirely by corporate and private contributions, won't use brooms or mechanical street sweepers to accomplish this goal - at least not directly. Its primary vehicle is television, and Executive Director Jonathan Phillips says that thanks to the free air time the organization is receiving from local television stations, as many as 100 anti-littering commercials a month will soon be broadcast.

These commercials will be aimed primarily at making many New Yorkers less apathetic about littering, so when they see someone toss a piece of paper or a banana peel on the street they won't hesitate to speak up about it - graciously, of course.

''We have one very broad goal,'' says Mr. Phillips, ''to substantially change public attitudes about litter. The kind of message we're trying to sell is that people don't have to accept littering anymore.'' Part of Phillips's optimism about the new campaign stems from a University of Washington study which showed that ''peer pressure'' can reduce littering by as much as 50 percent.

Meanwhile, many more traditional ways of reducing street grime appear to be making headway here.

''It appears that street cleanliness is improving very substantially now,'' says John Palmer Smith of the Citizens Budget Commission, a privately funded watchdog of the city's budget practices and services. In a report last February the group noted that street cleaning had begun to improve, Mr. Smith says, adding that this positive trend appears to be continuing.

One clear reason for this, city sanitation officials point out, is the greater number of street sweeping personnel. In 1974, the city had 2,500 street sweepers. By 1976 the city's deepening fiscal crisis had forced a drastic reduction of street sweepers from 2,500 to just 800. But in December 1980, the fiscal crisis began to wane and two-man garbage trucks began to replace three-man trucks, thus freeing up sanitation workers for other jobs such as street sweeping.

Currently there are 1,350 street sweepers. The city has also hired more enforcement agents to spot and fine litterers.

''But no matter how many street sweepers we have,'' says Vito Turso, a spokesman for the New York City Sanitation Department, ''we can still only do half the job. The people of New York will have to do the other half.''

Besides what We Care About New York and other nonprofit groups are doing citywide, a growing number of public schools and neighborhood associations are climbing on the anti-litter bandwagon. For some school children, there's an extra incentive for not being a litterbug: We Care About New York is giving out cash awards, though relatively small at this point, to students who make their schools the cleanest.