What was going on when I was born?

As the Union Carbide Corporation passes the first anniversary of the accident at its pesticides plant in Bhopal, India, the company is shaken by giant lawsuits, the threat of a takeover and low employee morale. No American company has had to deal with greater tragedy than Bhopal, where more than 2,000 people were killed a year ago Tuesday in history's worst industrial accident. Now, few companies face a more troubled future. Billions of dollars in Bhopal-related claims remain unresolved. A raft of other suits are pending over the toxic leak last August at the company's plant in Institute, W. Va. Samuel J. Heyman's GAF Corporation has acquired 10 percent of Carbide's stock and is seeking permission from the Securities and Exchange Commission to buy more. And a broad restructuring under way since August - aimed at reducing layers of middle management - has shaken Carbide's work force, according to current and former employees.

The Parti Quebecois, which once advocated at least partial independence from Canada, was overwhelmingly defeated tonight by the Liberal Party after nine years in office. The Quebec Liberal leader, Robert Bourassa, 52 years old, will return to the office of Premier, which he held in two governments from 1970 to 1976. As Liberals waved Canadian and Quebec flags and a band played at a celebration tonight, Mr. Bourassa said, ''What a great victory for Quebec, Canada, and for change.'' But Mr. Bourassa lost to his Parti Quebecois opponent in his own district of Bertrand, near Montreal. As a result, another Liberal may be asked to step aside to create a safe seat that Mr. Bourassa could win in a by-election.

RECENT excavations and interpretive work of scholars have pierced the shrouds that have enveloped the long-lost Etruscan civilization. It has become apparent that knowledge of the Etruscans, who dominated the Mediterranean lands well before the Romans entered history's center stage, has broadened substantially in recent decades, shedding light on such questions as where they came from, who they were and what language they spoke. Modern archeological exploration has veered from the vast burial sites that provided much of the early history of these vanished people to the remains of Etruscan temples, dwellings, storehouses and seaports that were much more difficult to locate than the cemeteries, and therefore less exposed to thievery. The latest research has been reviewed during an international Etruscan congress being held in Italy this year for some 800 scholars from Italy, other European countries and the United States. Findings were presented at a conference in Florence in about 100 papers to be published in a single volume next year.

When Anne Henderson-Pollard was arrested last month, she was planning to offer the Chinese a secret document that describes in detail what American intelligence knows about Peking's spying activities in this country, prosecutors asserted today. In a 23-page document filed in Federal District Court here, prosecutors contended that Mrs. Henderson-Pollard, who has been charged with obtaining classified documents, was more deeply involved in the alleged espionage activities of her husband, Jonathan Jay Pollard, than previously indicated. Neither Has Been Indicted The document is the Government's first assertion that Mrs. Henderson-Pollard had been intending to deliver secret documents to the Chinese. Her husband has been accused of selling secret intelligence documents to Israel. They have not been formally indicted and they have not indicated how they would plead.

In the largest takeover bid in British history, the Argyll Group offered $2.74 billion today for the Distillers Company, the world's leading maker of Scotch whisky, including the Johnnie Walker and Dewar's brands. The bid, which the Distillers board immediately attacked as ''unwelcome and completely inadequate,'' is the latest in a wave of hostile takeover efforts in Britain this year. The big bids have recently led to expressions of concern by corporate executives as well as by senior officials of the Bank of England. Despite the free-market leanings of the Government of Prime Minister Margaret Thatcher, some analysts say that pressure is building on the authorities to take steps to slow the merger activity. ''No company is safe now,'' one investment banker said. ''I think the Government is going to have to do something.''

A Texas judge yesterday denied the request by Texaco Inc. for a one-week delay in the hearing scheduled for Thursday to review the jury verdict that Texaco must pay the Pennzoil Company $10.53 billion. Judge Solomon Casseb, in the state district court in Houston, gave no reason for the decision, which clears the way for his review of the verdict and damage award. Judge Casseb may affirm the verdict, overturn it or reduce the amount of the damages to be paid by Texaco.

Texas has long been the bete noire of textbook publishers. The influence religious fundamentalists here have exerted on content has caused teachers nationally to complain that publishers soft-pedal their treatment of evolution and other topics to sell their books in Texas, which has more public school children than any state except California. Now a new commissioner of education and a new State Board of Education are slowly undoing years of fundamentalist influence.They have done nothing so dramatic as the California Board of Education did in September when it rejected about 30 science textbooks, saying they ''watered down'' evolution instruction to appease creationists, who hold that the Biblical version of creation should be given to ''balance'' the teachings of Darwinian evolution.

Has the artificial heart caused such severe medical complications that it should be used only as a temporary device to keep patients alive until a human heart transplant can be arranged? That is a question that has been raised with increasing frequency as doctors, ethicists and the public have become aware that the highly publicized artificial heart technology, which may some day play a major role in American medicine, is currently causing adverse reactions in most recipients. The problems have spawned a variety of opinions on the appropriate role for the artificial heart in its current early state of development. Experts have clashed over whether the artificial heart can most effectively be used as a permanent implant in selected patients, or as a temporary ''bridge'' to keep patients alive while they await a human heart, or for both purposes, or neither. The most vigorous proponents of the artificial heart believe it can save lives that would otherwise be lost when used as either a permanent or temporary implant. The most vigorous critics of the technology believe that a permanent implant is dangerous and that even temporary implants will do more overall harm than good to the public health.

The Reagan Administration, responding to the acquittal of Gen. Fabian C. Ver in the Aquino assassination trial in the Philippines, said in carefully worded statement today that the court decision was at variance with the findings of an independent investigation. A State Department spokesman said it was ''very difficult'' to reconcile the outcome of the trial with the findings of a citizens' panel that military personnel were involved in the slaying and a cover-up. Earlier today, a three-judge court in Manila acquitted General Ver and 24 other military men and one civilian for the 1983 murder of the opposition leader Benigno S. Aquino Jr. 'Very Difficult to Reconcile' ''Recall that in October 1984 the Agrava Commission, a board of respected, independent-minded citizens, unanimously refuted the government contention that a lone Communist gunman killed Senator Aquino,'' said the State Department spokesman, Charles E. Redman. said. ''The board found the murder to be the work of Philippine military personnel who were charged with the crime and the cover-up.

''This proves that people can successfully reduce their cancer risk by quitting smoking or not taking up smoking.'' - Dr. Vincent T. DeVita Jr., director of the National Cancer Institute, on lung cancer report. [A1:1.]

Apartment dwellers could see a 15 percent increase in rents if Congress enacts the cutbacks in real estate tax benefits included in the House Ways and Means Committee's tax revision bill, spokesmen for landlords and builders said today. However, some analysts said rent rises would be smaller or negligible, although they agreed that the bill would lead to a slowdown in construction of new rental apartment buildings, particularly for low-income families. Most other residential real estate, chiefly owner-occupied houses and condominiums, would be little affected. The committee's measure would fully retain the deductions for mortgage interest and property taxes on principal and second homes.

Social Service officials said yesterday that they would stop mailing welfare checks to three Manhattan hotels that they said had provided scores of welfare recipients with fradulent addresses to obtain benefits. They acted several hours after Mayor Koch said the city had known about the practice in at least one hotel since April 1984 but had gone on paying a total of $450,000 in apparently fraudulent checks to avoid jeopardizing an investigation by Robert Morgenthau, the Manhattan District Attorney. But that account was disputed by Mr. Morgenthau and his staff. They said that until last week, when new information surfaced, they had never asked the city to go on issuing fradulent checks, and assumed the city had already dealt with the problem.