August 3, 1983

Six different armies were involved in clashes inside Lebanon today, underlining the steady deterioration of the country's security situation. Palestinian guerrilla factions fought with each other and with the Lebanese Army in the central Bekaa, the eastern valley. Israeli troops, battled with Syrians in the southern Bekaa, and other Israelis clashed near Sidon with Phalangist Christian militias, whom they are trying to evict from southern Lebanon. U.S. Envoy Meets With Gemayel The fighting among the various Lebanese groups and occupation forces formed the backdrop for the first foray by the new American special envoy, Robert C. McFarlane, into the Lebanese crisis. The American diplomat, who arrived in Beirut Sunday night, met for 45 minutes today with President Amin Gemayel in the mountain village of Bikfeiya, northeast of Beirut. They apparently discussed new American ideas for obtaining the withdrawal of all foreign forces from Lebanon.

The American Cancer Society announced new guidelines yesterday for breast cancer detection, stating that women 40 to 49 years old should now have regular mammograms. It previously recommended the specialized X-ray technique on a routine basis only for women over 50. The society said the change was prompted by recent improvements in mammography, resulting in much lower radiation doses and better detection ability, and by new demonstrations that mammography was the most effective method of finding early, presumably more curable, breast cancer in younger women. Technical innovations have now made it possible to detect tiny cancers in the dense breast tissue of young women.

The Medical Society of the State of New York yesterday issued its first guidelines for investigating and reporting complaints of incompetence or misconduct by physicians. ''The guidelines mean that any complaint against a physician will not get lost or not be hidden,'' said Donald Moy, the society's general counsel. ''The guidelines are a part of the State Medical Society's commitment to cooperate with the State Department of Health and the Hospital Association of New York State in working out a constructive approach to the issue of incompetent or impaired physicians,'' the society said in a statement.

The Long Island Rail Road and four of its unions announced tentative agreement on new contracts early this morning, averting a strike that had been scheduled to begin at midnight last night. Walter C. Wallace, chairman of the Federal Mediation Board, announced the settlement at 12:30 A.M. today, noting that as a result, ''there will be no interruption of service'' for the line's 145,000 daily riders. He declined to discuss the settlement terms ''at this time,'' noting that the tentative contract agreements remained suject to ratification by the four unions, representing 1,900 carmen, electrical workers, sheet metal workers and machinists, and the Metropolitan Transportation Authority, which oversees the operations of the L.I.R.R. Robin Wilson, the president of the railroad, said he was ''delighted'' with the agreement. He praised the members of the four unions for ''doing a fine job on the railroad,'' and said ''this agreement will assure the continuing improvement in that service.''

Eighteen years ago, when the Federal Government took over the Ocean Manor apartments here through a mortgage foreclosure, the 10-story complex was considered a white elephant - a home for moderate-income elderly people in the shabbiest part of a shabby city. But with the coming of casino gambling, the boardwalk, even in its most decayed stretches, once more became a desirable address. Now the Government, which paid $4 million for Ocean Manor, thinks it is worth as much as $30 million, and like other owners of once neglected properties here, it wants to sell and realize a profit. The prospective sale has frightened the manor's 250 elderly residents, many of whom have already been forced to pick up and move at least once since casino gambling arrived in 1976 - from the President Towers, the Ritz-Carlton and other hotels along the boardwalk.