The Greeks have a word for it: "catastrophic." It's the best word to describe the effects of modern-day industrial pollution on the 2,400-year-old monuments of the Acropolis.

According to archeological experts, the complex of marble monuments, which include the Parthenon and Erechtheum temples, has sustained more damage in the last 25 years than in all its previous existencs.

The same period has seen the Greek capital of Athens, whose skyline is distinctively dominated by the Acropolis hill, transformed from a picturewque Mediterranean town to a concrete high-rise sprawl accommodating more than two-thirds of the nation's industry and 40 percent of its population. m

In the resulting crush of men, machines and monuments, only the machines seem to have come off well. ythe air above Athens today is a vertible cocktail of pollutants, including sulfur dioxide, carbon monoxide, smoke and ozone. In recent months, the atmospheric levels of these substances exceeded those for Los Angeles, a city that provides a handly analogy for the temperature inversions that periodically act to smother Athens under a lurid photochemical cloud.

"The quickest damage to the monuments i caused by the sulfur dioxide," said George Dontas, director of the yacropolis antiquities and a member of the seven-man Acropolis Preservation Committee created in 1977 to oversee the drive to save the monuments. "As it combines with rainwater, it forms sulfuric acid, which eats into the marble and changes it to plaster. ywind and rain do the rest, by washing away the stricken detail. The six carayatid maidens, whose statues form a portico to the Erechtheum temple of Athena and Poseidon, have suffered just this kind of damage."

The main source of pollution is found west of the capital near Eleusis, once the center for the fertility cult of the earth-goddess Demeter, now the heart of a dreary coastalstretch of oil refineries, steel mills and dockyards whose daily belching of amoke and noxious fumes is pushed toward Athens by the prevailing southwesterly winds.

These industries, together with an inner-city municipal power plant and oil-fired central heating systems in apartment buildings, account for 55 percent of the atmospheric sulfur dioxide. The city's nearly 1 million cars do most of the remaining damage.

In 1976, an international symposium of experts met in Athens and drew up a plan to reconstruct the Acropolis monuments. As part of the first stage of the project, the caryatids, were removed in 1979 to the safety of a nitrogen-bathed museum display case and replaced with white cement copies. The present stage is dedicated to the reconstruction of the Erechtheum.

Aside from pollution damage, the Erechtheum and the other Acropolis structures have suffered the consequences of ill-conceived repairs carried out in the first part of the century. The iron joints and supports used as reinforcement in those repair projects expanded as they rusted over the years and cracked the very marble they were intended to support.

In the present project, the damaged parts of the Errechtheum are being dismantled and reassembled using supports made out of titanium, a metal with 500 times the resistance to rust and twice the tensile strenth of stainless steel.

"Had it not been for the cracking caused by the iron, the Parthenon would not have sustained the damage to its southeastern corner -- luckily, not very great -- which ocurred as a result of the recent earthquakes," Dontas said, referring to a series of quakes measuring up to 6.6 on the openended Richter scale that struck the Athens area in February and March.

In conjunction with th erestoration work, research is being carried out at the University of Athens on a way to protect marble against atmospheric pollution. A seven-person team working under Dr. Theodores Skoulikidis, a professor of inorganic chemistry, has analyzed the chemical mechanism whereby marble turns into plaster.

"Now we are trying to develop a substance that could be painted or sprayed onto the marble and would prevent the change to plaster from happening," Skoulikidis said.

In the variation of the medieval alchemists search for a formula to turn lead into gold, the Greek team has also addressed itself to the problem of changing plaster back into marble. "It is indeed possible . . . by subjecting it to high pressures and temperatures in an atmosphere of carbon dioxide," Skoulikidis explained. "And we are now trying to put this process in a can, by developing a highly concentrated ionic spray to do the job. But all this is still very experimental."

Research of this kind will be boosted by a laboratory and teaching center to be set up this year, with the help of $350,000 from the United Nations Educational, Scientific and Cultural Organization. The money was collected after an international appear in 1975 to save the Acropolis, but was set aside whent he Greek government, for reasons of national pride, decided to fund the preservation project itself.

But those involved in the Acropolis project agree that no amount of scientific wizardry will save the monuments if it is not backed by drastic measures to limit pollution.

So far cars and buses have been banned from the Acropolis hill and airplane flight paths changed to avoid overflying the monuments on takeoff and landing at Athens airport. A 1978 law mandated the use of low-sulfur oil in central heating, and the municiapl power plant in the inner cityis scheduled to begin using this type of fuel in April.

Prohibiting access to certain areas of the monument, moreover, has minimized the wear and tear of about 5 million eager tourist heels per year.

But the worst culprits, the industries to the west of Athens, remain resolutely oblivious to the pollution problem, which Skoulikidis ascribes bluntly to "a reluctance on the part of the industrialists involved to spend money on antipollution measures, coupled with a reluctance on the part of the authorities to press them into taking these measures."

"We have not, it's true, been pushing too hard for antipollution measures, which after all are sometimes beyond the economic means of a small industry," says Georghios Pappas, general secretary to the Ministry of Industry and Energy. But he said new industries have been banned in the area and a recent law provides government grants and loans for antipollution projects.

Meanwhile, the reconstruction work on the Acropolis progresses painstakingly, with the Parthenon next in line for a total structural overhaul."But before we start we would like to hold another symposium to secure international backing afresh for this part of the project. Taking a monument such as this apart and putting it together again is no joking matter, and the Acropolis is important not only for Greece but for the world," Dontas said.