For 30 years, I sent them packages and money. But when I came here, nobody was at the station. They were afraid."

The speaker is a tiny and vivacious 80-year-old polish-American. Agnes Kurski. She came to the Polish capital eight years ago, clutching her U.S. Social Security checks and hoping to find a comfortable and less expansive way to live out her years among old friends and family.

Thousands of other Polish-Americans have done the same.

Each month, some 4,500 Social Security and other forms of government retirement checks flow from the United States through the embassy here to help support 6,000 to 8,000 elderly Americans who have come back to the old country where the dollar is still a sought-after currency.

It is by far the largest concentration of American pensioners in all of what has been Communist Eastern Europe since the end of World War II.

In many cases, things have worked out well, but there was also sadness for some.Since new Polish laws took effect this month, however, there are now potentially tough economic problems ahead for many more.

In the case of Agnes Kurski - not her real name - the reminder that she was in a different Poland from the one she remembered began at the train station. Although she has several close relatives here that she had not seen since before World War II, someone in the family apparently convinced the rest that the Communist authorities might become suspicious if they took an American into their home.

To an outsider, such fears appear exaggerated, since Poland is generally considered among the more liberal Communist states. But it is symptomatic of easily triggered fears just beneath the surface here and Agnes Kurski continues to live alone in a tiny Warsaw apartment.

"I came back here because I was born here," she says in her accented English. "I love Poland. My hear is Polish. Would you not love America even if the Bolsheviks come?" she asks.

"Poland is not free, as everybody knows. But I'm not unhappy because I don't think about politics. I think about music and Poland is a lovely country for music."

But Kurski says she also came back because she could not afford to take care of her ailing husband on their $200 pension check in the United States and they were "too proud" to go on welfare. He has died since they arrived here.

In the Warsaw suburbs, another Polish-American retiree, Josef Bitka, 69, is the envy of his neighbors. The pensioner, who never spoke more than a few words of English, worked with his wife in the United States between 1965 and 1975, enough to qualify for Social Security. He worked in a chewing gum factory and she as a cleaning woman.

They saved their money, helped their children buy homes in Chicago then came back and bought their own home here, with their Social Security plus a small pension from the factory. it is enough for a pleasnat retirement.

Polish-Americans can bring their dollar savings into Poland but their cannot be cashed here for dollars. Instead, they are converted into Polish Zlotys at what has been generally favorable rate in comparison with the official tourist rate.

In addition, 20 per cent of the check's value is refunded in "dollar coupons." These allow the recipient to buy in special hard-currency shops that sell sought-after Western goods - from chocolate to sport clothes - that are not available to other Polish citizens.

it is with these coupons that most retirees here really make their money. Poles will buy these coupons for five times the official tourist rate of exchange so that they, too, will be able to go into the government-run special stores.

The zloty is one of the least valuable currencies in the Communist bloc, while the Poles have perhaps the greatest appetite for Western goods. This has sparked the joke here about why the United States and Poland are exactly alike - because in neither country can you buy anything with zlotys.

The rate on the black market - which is open and thriving in Warsaw - is about 150 to the dollar, which is reflective of the zloty's real buying power.

The official tourist rate is 33 zlotys to the dollar. The official rate of exchange for Social Security checks has been 45 to the dollar. (In the the past it had been much higher.)

What alarmed the U.S. pensioners, however, are new regulations that dropped the check-cashing rate to coincide with the 33-zloty tourist rate, beginning Jan. 1.

While no change was made in the 20 per cent coupon arrangement, the government was on the brink of canceling it last month and there is widespread concern here that the arrangement will end eventually.

The economic squeeze has brought complaints from several retirees here that American officials have not been protecting their interests by interceding with the Polish government to maintain a realistic price for their dollars.

Some, whose extra zlotys allowed care by a private doctor, are worried that they might have to shift to crowded polish clinics. Others foresee facing shopping conditions characterized by long lines that they are too old to cope with. Many cannot afford to go back to the United States because they can withdraw only zlotys - not dollars - from Polish banks.

"The only way to cope may be to send our checks back for cashing and try to smuggle in dollars. Why, at my age," asks an 85-year-old pensioner, "should I have to smuggle checks?"