What was going on when I was born?

The following article is based on reporting by Ralph Blumenthal and Ben A. Franklin and was written by Mr. Blumenthal. Garbage companies dominated by organized crime have been secretly and illegally dumping vast quantities of dangerous chemicals throughout the New York area, according to law-enforcement authorities, court records and police informants. The accounts tell of hazardous wastes flushed into suburban sewer systems, poured into garbage landfills, dumped into waterways, mixed into heating oil, stacked in warehouses and buried in unmarked pits. Officials say it is impossible to assess the health effects of the illicit disposal. Such dumping has long been suspected, but confirmation and details of the schemes did not come until a recent series of investigations and prosecutions.

Can a drug so apparently straightforward that doctors routinely prescribe it for overweight people be affecting the outcome of thoroughbred horse races around the country? According to recent veterinary research, the drug - furosemide, better known as Lasix - prevents water-weight buildup in people but also seems to make horses run faster. Even more baffling, no one is sure just why that is. ''Lasix can turn a $10,000 horse into a $50,000 horse and a slow one into a fast one,'' says Jerry Fanning, the trainer of Desert Wine, who ran on Lasix when he finished second in both the Kentucky Derby and the Preakness last month. Other trainers who use the drug on their horses agree with that assessment, and that concerns veterinarians and racing officials. After several years of achieving hard-earned reforms that have brought much abuse of illegal racing medication under control, they are beginning to suspect that Lasix, a drug which has been sanctioned for widespread use to control bleeding, is among the most potent and volatile of all.

Frank Howard, in his first full day as the 10th manager of the Mets, conceded today that the Mets needed help because ''we can't go on the way we've been going.'' But neither he nor his bosses offered an immediate plan to rescue the new manager from the old problems he had inherited from George Bamberger. ''There is no question we have holes to fill,'' Howard said. ''We have had seven years of frustration and, let's face it, bad baseball. You need quality ballplayers, and total effort from them. But, for now, we have to play with the players we have.'' Frank Cashen, the general manager of the Mets, did not promise any radical moves or major trades to keep the club's rebuilding program from collapsing. He acknowledged that the team needed a No.1 catcher because John Stearns was still disabled. But he reported that no ''hot deal'' was on the table.

Governor Kean toured the city's Ironbound section today and sought to assure residents that there was no evidence that dioxin contamination had spread beyond an abandoned chemical plant. The Governor was generally well-received by the area's homeowners as he walked door to door in the blue-collar neighborhood near the Passaic River. On Thursday, Mr. Kean ordered the closing of a food distribution center and offered to pay to lodge as many as 100 residents at a Y.M.C.A. So far, no one has made the move. Eugene Foltzer, who owns an Exxon station a few blocks from the plant, spoke with the Governor at the entrance to the old Diamond Alkali Company plant, at 80 Lister Avenue, where the high levels of dioxin, a toxic chemical, were identified this week.

''In school, you learn silly things like, 'the Middle Ages means barbarism.' In my film, I tell a very modern story that happened to take place in the 16th century,'' said Daniel Vigne, director of ''The Return of Martin Guerre.'' Based on a famous love story and trial that inspired a play, two novels, an operetta, and a soon-tobe-published historical account, this award-winning French film opens Friday at the 68th Street Playhouse. ''The Return of Martin Guerre'' gives new life to a legendary folk tale by insisting on its ''timelessness'' - of setting, images, music, and story. It was shot in a French peasant village which has remained virtually unchanged since the 1550's; 40 kilometers away was the actual town where a youth named Martin Guerre married Bertrande de Rols, disappeared for nine years, and returned to reclaim his wife and land. With visual compositions that recall Flemish painting and music that blends medieval sounds with electronic instrumentation, the film conveys the flavor of the Middle Ages as well as the modernity of the tale's implications - about justice, revenge and especially love.

Westchester County has long been viewed as golden territory by the metropolitian area's corporate community - and much of the county's office-building devlopment has been concentrated in the southeastern section of the county. But in the last few years, such corporations as Revlon, Union Carbide and Stauffer Chemical Corporation have discovered the Route 9A corridor known as Westchester's west side.

Two years after coming to power, President Francois Mitterrand is facing a crisis of confidence in his management of the French economy. The austerity measures he introduced in March to head off a fourth devaluation of the franc are starting to bite. This month taxpayers found their regular tax bills swollen by a 10 percent forced loan to the Government in addition to a special emergency levy. Currency controls are forcing many French people to take vacations at home this summer. Bankruptcies and unemployment are on the rise.

Five hundred years after Martin Luther was born, his vast works are being examined by both Protestant and Roman Catholic scholars seeking fresh insights for an ecumenical age. ''Studies of Luther are growing very rapidly,'' said David Daniel, a professor at Concordia Theological Seminary, where one of several conferences marking Luther's 500th birthday ended today. ''Luther has become a man of Christianity, not just for Lutherans.'' Fruits of this scholarly research were evident at the Concordia conclave. Talks liberally laced with German and Latin quotations from Luther shed light on such subjects as Luther's views toward women, his sudden hostility toward Jews, his vigorous search for authentic Christianity and his disputes with Catholic opponents.

IT'S getting harder and harder to be poor and get food stamps in Suffolk County. The number of banks that distribute the stamps has dropped from 51 to 24 in the last several months, making it difficult for food program recipients to get the stamps. As a result, the Suffolk County Department of Social Services will begin an experimental stamp-distribution program tomorrow at its center in Coram, where food stamps will be dispensed through bulletproof teller cages protected by armed guards who will deliver the stamps to the center in an armored truck. The distribution problem reached a crisis point in late April when the last two bank branches serving the Coram area announced that they, too, would no longer serve as distribution centers. Bank officials said that while they felt they should be of service to the community, their regular customers had complained that they were inconvenienced by the food stamp recipients, whose presence caused them to wait in long lines.

As spring ends and music schools disband for the summer, professors go in one direction, pupils in another. For both parties -for the young musicians who hover between artistic childhood and professional life and for those who teach them - there is a chance to reflect again on how time and circumstances are constantly altering the delicate blend of imposed authority and individual creative juices which marks one-to-one music training. The mythology of teacher-student relationships is a rich one, and every music biography has its early chapter on these encounters - how an undisciplined child named Franz Liszt met the literal-minded, pedantic Czerny, how Martin Krause in Berlin both inspired and terrorized his young pupil Claudio Arrau, how Beethoven, unsatisfied by his studies with Haydn, sought training from others on the sly. Karl Leimar and his great pupil Walter Gieseking profited, on the other hand, from a oneness of vision. The music world marveled at how Gieseking was able to play music simply by having read it in an airplane on the way to a recital date. (Gieseking once said with a straight face that if forced to practice at the piano, he would have been too tired to play the concerts.)

HIS professional career spanned half a century. During his lifetime other painters, such as Gilbert Stuart, lavishly praised his work. And after the death in 1807 of Edward Greene Malbone, America's foremost painter of miniatures, Anson Dickinson of Milton was considered by many to be this country's finest portrait miniaturist. Strangely, however, since his death in 1852 Dickinson was virtually neglected by art historians. There was no major show or catalogue of his work.

ALTHOUGH the reasons are not clear, there is a growing interest on the Island in all-day, or extended, kindergarten programs. Some people attribute the trend to concern about education; others say it is based on economics or a combination of the two. ''There are lots of pluses in full-day kindergarten, but we must look at what's best for the kids,'' said Bertha Campbell, supervisor of the Bureau of Child Development and Parent Education in the New York State Education Department. Whether 4- and 5-year-olds are able to learn more or faster in such a program is debatable and is one of the main reasons that school districts are cautious in their consideration of a full- or extended-day kindergarten. ''Some studies show it's much better if you send them to school all day; others say there's too much pressure and the kids don't do as well,'' Mrs. Campbell said. ''In fact, some might begin to hate learning.''