What was going on when I was born?

The Environmental Protection Agency today proposed stringent new rules requiring producers of iron and steel to cut down substantially on the toxic substances and other pollutants that they discharge into the nation's water supply. The agency estimated that the new ''effluent guidelines'' could cost the industry more than $1 billion over the next 10 years. The proposed rules would not take effect until after public comments and further review. An official of the American Iron and Steel Institute, a trade group, indicated that the industry would probably ask the administration of President-elect Ronald Reagan to stretch out the deadlines for complying with the rules so as to ease the capital squeeze on steel companies, which are already afflicted by a capital shortage. He said this squeeze was affecting the companies' ability to compete with foreign producers.

The ski industry in the eastern half of the country has roared back to life this winter as record cold temperatures and small but regular snowstorms combined to bring skiers streaming back to the slopes. A year ago the worst season in the industry's 45-year history left grass showing through the slopes at Christmas and merchants lining up for Federal disaster loans at Easter. Another year like ''the year without snow'' would have meant bankruptcies and severe economic dislocations in the band of poor rural communities from Maine to Pennsylvania that depend on the $3.5-billion-a-year industry. A Brief Business Season But the snows came this season, in time for the Christmas and New Year's holidays, the brief period in which most ski businesses do a third of their volume.

The Algerian intermediaries returned here today with the latest United States proposals and terms for the release of the 52 American hostages. The three intermediaries - the Ambassador to Washington, Redha Malek; the Ambassador to Teheran, Abdelkarim Gheraieb, and the director of the Algerian Central Bank, Mohammed Seghier Mostefai - arrived at Mehrabad Airport by special plane this morning, after four days of talks in Washington. They were met at the airport by Ahmad Azizi, the Government's Director of Hostage Affairs. There was no official comment from the Iranians, although they were presumably given the United States position paper. Friday is the Moslem Sabbath and all Government offices were closed.

Banks across the country, reversing a pattern of rapid increases in their loan charges since mid-November, dropped their prime lending rates yesterday to 20 1/2 percent from a record 21 1/2 percent. The move to the lower level by almost every major bank followed by several days scattered reductions in the prime rate by four large banks: Wells Fargo, Chase Manhattan, Chemical and Irving Trust. Economists and bank executives said the rate cuts could signal a gradual decline in loan charges. But they warned that the decline would not be so steep or so rapid as last year, when the prime rate fell from a peak of 20 percent in April to a low of 10 3/4 in July.

Using campaign contributions, computer programs and careful planning, the Republican Party has positioned itself to take advantage of the 1980 census figures when the Congressional and state legislative redistricting battles are fought in the 50 state capitals this year. The final figures themselves are encouraging to the Republicans because they will mean a loss of Congressional seats in urban, almost automatically Democratic areas, where population has declined. Most of the 17 House seats in the North and Middle West that will be shifted to Sun Belt states will come from such urban centers. But the Republicans also stand to gain significantly more control of the redistricting process itself in several states because of their gains in state legislatures and governorships.

More than two-thirds of the nightclubs, discotheques and social clubs in New York City are in violation of a law requiring them to install improved fire safety devices, according to officials of the Department of Buildings. And they said that nearly half the city's high-rise office buildings were in violation of a separate law requiring them to file plans for the installation of fire safety devices that must be in place by next September. Both kinds of violations are considered serious because the improved measures were adopted after investigators determined that they might have saved lives in previous fires. The officials have promised to enforce the laws strictly, and inspectors have issued summonses against 1,000 buildings, ordering the owners or managers to appear in Criminal Court.

Despite a recent effort to create a fair legal system and prevent a renewal of the arbitrary persecutions of the Cultural Revolution era, China still operates a vast network of labor reform camps populated by hundreds of thousands of prisoners. That conclusion emerges from interviews with dozens of former inmates whose accounts portrayed a system under which the work is hard, the food scanty and the punishment often brutal. A few months ago, a white-haired 70-year-old former Protestant minister was released from a labor camp near the city of Datong in Shanxi Province in northern China. He had worked there in a coal mine, along with 10,000 other prisoners, scraping up chunks of black rock with his bare hands for 23 years. He had been sentenced to laodong gaizao, or ''reform through labor.'' He had been accused, he said recently, of being an ''American spy.'' Having gone to divinity school in the United States, he had returned to China in 1949, after the triumph of the Communists, When he was convicted in 1957, two agents of the Public Security Bureau, or police, said there was no need for them to prove the charge. They said that he had been given his orders in America and that they could not go there to produce the evidence.

Turkish martial law authorities have detained the president and nine professors of the Academy of Economic and Commercial Sciences in Adana, according to authoritative sources in that southern industrial center. This is the first sweep in academic circles since the armed forces seized power on Sept. 12 and has caused concern among Turkish intellectuals, who recall the harsh crackdown on left-wing intellectuals during a military intervention a decade ago. Security forces would give no reason for the detention of the academy members, except to say that it was part of ''an important operation'' and that the details would be released shortly.

The friendship between West Germany and France, a basic element in Western Europe's relationship with both the United States and the Soviet Union, is losing some of its warmth. There have been no open clashes or publicly argued differences of opinion because they would serve little purpose, but officials in both capitals are acknowledging that the need the two countries felt to view world events with the same European outlook has diminished. Although neither side will say it even privately, the result of the process might be that the Reagan administration will find its dealings with both allies somewhat simplified. It appears increasingly clear that France and West Germany will have a harder time working out joint policies that would situate them between the Americans and Russians.

For the second time in a week, a top guerrilla commander has said that leftist insurgents will soon open a military offensive to overthrow the Government. ''I cannot give you the exact date or hour, but we are very close to our final battles,'' said a middle-aged rebel leader who gave her name only as Anna Maria. ''This is the decisive moment.'' Speaking softly, her identity further disguised by a red beret and neatly folded triangular red bandana covering all but her eyes, she said that the final offensive would include direct military attacks, a general strike and insurrection by the people in small cities and in the poor areas of the capital.

Nadezhda Mandelstam, widow of Osip Mandelstam, the poet who died in a Stalinist purge, was buried today on the outskirts of Moscow. A police jeep and a black sedan with plainclothesmen waited nearby in case of demonstrations by the several hundred friends and admirers who went to the cemetery to pay tribute to her and her husband. The poet perished in a transit prison camp in 1938 after being arrested as ''enemy of the people.'' There were no speeches - only the singing of Russian Orthodox liturgy as eight men carried the coffin at the head of a procession along the cemetery's icy trails.

Israeli casualties from terrorist incidents dropped by more than half in 1980, according to an army report made public yesterday. The report said that Israel's policy of preventive strikes at Palestinian bases had ''paralyzed'' terrorist activity.