LAKE BAIKAL, U.S.S.R. -- "Make Effective Use of the Natural Resources of Siberia!" proclaimed the faded propaganda board by the side of this unique, mile-deep lake that contains one-fifth of the world's fresh water supply.

Nearby, a pile of white marble mined from the mountains that rise up around Baikal was lying abandoned. Some 15 miles away, across the translucent waters of the beautiful inland sea, a cellulose plant was pumping black clouds into the blue sky. On the other side of the lake, dozens of factories around the city of Ulan Ude were releasing chemical pollutants into the Selenge River, which provides Baikal with half its water.

"Nobody bothers to think about these slogans, what they mean or how to implement them," murmured Vadim Firsov, an inspector of a newly created official watchdog agency over the environment, shaking his head in disgust. "They just sit in their offices, dreaming up anything. No wonder things are going badly."

Rapid industrialization and decades of centralized rule have turned much of Russia, the largest and richest of the Soviet Union's 15 republics, into an environmental disaster area. The spectacle of chronically polluted lakes, rivers and cities has in turn inspired millions of Russians, and many communities of Siberians, to demand the right to run their own affairs.

"The idea of Russian sovereignty originated with the destruction of our environment and the plundering of Russia's resources," said Gennadi Filshin, the newly elected deputy prime minister of Russia, whose political career began with the campaign to save Lake Baikal. "The efficient use of resources is possible only when a real master of those resources appears. As long as decisions affecting the future of Siberia were made by some bureaucrat in Moscow, mismanagement was inevitable."

The greening of Russian public opinion has been particularly evident in Siberia, the source of most of the Soviet Union's oil, timber and hydroelectric energy. For centuries, Siberia was regarded as a land of virtually unlimited natural resources and endless spaces. The Siberian treasure house enabled the Soviet Union to become a global superpower. Over the past few years, many Russians have begun to understand that Siberia's wealth is limited and needs careful husbanding if future generations are to benefit.

Pollution is no worse in Siberia than in other parts of the Soviet Union -- and in remote regions, considerably better. What makes the situation here particularly dramatic, however, is that the process of industrialization has been violently compressed. Vast areas of taiga, or natural forest, have been torn apart to make way for cities and industrial complexes. The ecological threat to Lake Baikal, which is at least 25 million years old and is home to 2,000 different plants and animals found nowhere else in the world, has developed within the lifespan of a single generation.

"Nature is taking its revenge," said Grigory Galazi, a marine biologist who has been at the forefront of the campaign to save Baikal, predicting that the cleanup of the lake will take many decades. "Nature is bountiful. She gives loans very easily. But she also charges interest on these loans that far exceed the original capital. It's taken a long time for us to realize this."

For many activists, the pulp-paper combine at Baikalsk has become a test case of the willingness of Russia's new government to take tough measures to protect the environment. Situated at the southern tip of the lake, it is the only major industrial enterprise on Baikal. A 1987 Kremlin decree ordered its closing or transformation into an ecologically harmless furniture factory by 1993. But there is no sign of this happening.

The pulp mill was built in the early 1960s, in the middle of the headlong dash toward the industrialization of Siberia. At the time, environmental issues were of little concern to Soviet leaders. There were practically no outlets for the expression of independent public opinion. In order to make the Soviet Union a global superpower -- and catch up with the United States -- industrial production had to be increased, whatever the cost.

The Ministry of Forestry Industry argued that the ultra-pure water of Lake Baikal was needed to produce super cellulose cord for aircraft tires. In order to produce 1 ton of pulp, 375 tons of fresh water and about 500 pounds of sodium sulfate -- much more than in Western countries -- are required. The filthy wastes are purified, but, even so, the water pumped back into the lake is considerably less pure than the water extracted a few miles away. It also has an unpleasant odor.

The pulp plant's managers say their opponents have not been able to produce hard evidence that the factory constitutes a serious ecological threat to Baikal. They are also dismayed at the negative publicity their factory has been receiving in Russian newspapers, which have become much more sensitive to environmental controversies.

"We are depicted as irresponsible polluters. But we love Baikal as much as anyone," said Viktor Kostigin, the deputy director of the plant. "Our news media have begun to blacken everything and everyone. A few years ago, they said that everything was wonderful in the Soviet Union. Now they say that everything is terrible."

The environmentalists concede that the pulp plant is far from being the only threat to Baikal. Sewage and industrial wastes from Ulan Ude, a new railroad line along the northern shores of the lake, air pollution from the industrial cities around Irkutsk have all exacted their toll. But they question the need for a huge industrial complex right next to a lake that is as much a part of Russia's natural heritage as the Grand Canyon is of America's.

The marine and plant life of Baikal has already suffered as a result of the cumulative effects of pollution. The omul, a slender, salmon-like fish native to Baikal, has lost half its average weight over the past two decades. Its traditional spawning grounds in the estuary of the Selenge have been covered by sunken logs. The nerpa, the world's only fresh-water seal, could also be endangered if industrialization continues at its present rate.

"By destroying Baikal, we are destroying the basis of our own life," said biologist Galazi, in an interview in Irkutsk. "Human beings are themselves 60 percent water. Life first appeared in water -- pure water, not water that has first gone through a pulp plant."

The uniqueness of Baikal was underlined in August when a team of Soviet and American scientists announced that they had discovered a field of hot air vents at the bottom of the lake. The vents, which support a rich variety of life in the lake, are the first such formation to be found in fresh water. The scientists now believe that the scimitar-shaped lake could develop into an infant ocean as Asia splits apart.

From the balcony of his home in Angarsk, about 60 miles northwest of Baikal, the newly elected president of the regional environment protection committee has a grandstand view of a chemical plant. The plant produces almost as much airborne pollution as the whole of Moscow, which has been declared an environmental crisis area.

"This is why I became interested in the environment," said Ildus Gapyautdinov, pointing at the clouds of noxious black smoke spewing out of the chemical plant. "For 73 years, we have had a policy of exploiting our resources without caring about future generations. It's not until there was a crisis that people began to stop and think."

The prevailing winds usually disperse the pollution from the Angarsk chemical plant over Baikal. But sometimes, when the winds are in the wrong direction, it floats back over Angarsk, a typical Stalin-era industrial city of workers' apartment blocks and grandiose public buildings. Local residents complain that breathing becomes more difficult and that the rain contains a corrosive acid.

It is difficult to calculate how much damage the Angarsk plant does to public health. But across Russia, the effects of environmental neglect are evident. Russia is one of the few places in the world where life expectancy has actually fallen over the last decade. It is now down to an average of 65 years, 8-10 years lower than in most industrialized countries. Every second Russian called up for military service is declared physically unfit.

According to official statistics, ecological crisis zones now cover roughly 16 percent of Soviet territory. Between 50 and 70 million people live in regions officially described as "ecologically unhealthy." Baikal is officially classified as a "crisis zone," one notch down from a "catastrophic zone," meaning that it will take decades for the environment to recover, even under the most favorable circumstances.

The means available to rectify this state of affairs seem pitifully small. The past two years have seen the formation of republic-level and regional environmental committees that have the task of monitoring the ecological situation and punishing offenders. But committee officials acknowledge that government decrees and resolutions on the environment are frequently unenforceable.

"Much of the pollution comes from cars -- but what can you do when 4 out of 10 cars violate official standards," said Firsov, the environmental inspector, driving past a truck spewing black smoke. "Generally we fine people only 5 to 10 rubles {$7 to $15 at the official exchange rate}. We have to educate people gradually. We cannot be too radical. Otherwise there would be a revolution."