ENVIRONMENT : Fears Rise Over Nazi Weapons Leaking at Bottom of the Baltic : Tons of chemical weapons, dumped by the Allies after World War II, have nudged the sea to the brink of catastrophe, scientists say.

Just 100 yards under the wind-whipped surface of the Baltic Sea, hundreds of thousands of Nazi chemical weapons, hastily dumped by the Allies after World War II, are leaking deadly gases into the murky water.

According to Russia’s fledgling Green Party, the toxic chemicals oozing out of corroded bombs and grenades could soon reach a fatal concentration, threatening not only the Baltic’s marine and plant life, but also the 30 million people who live along the coastline.

By tossing 300,000 tons of ready-to-fire weapons--enough to kill the entire population of Europe--into the shallow sea from 1945 to 1947, the United States, Britain and the Soviet Union nudged the Baltic to the brink of catastrophe, scientists say.

“The Baltic Sea is known as the chamber pot of Europe,” said Yevgeny Usov of Russia’s Green Party, which raised the first alarms about the submerged chemicals two years ago. “Already, there are strong poisons in the sea, eating at its ecology like a cancer. If you add to this the dispersion of toxic chemicals, you can surely expect the sea to perish altogether.”

The Green Party predicts devastating deaths of marine life within the next three years as the Baltic’s salt water completes its decades-long work of eating holes in the weapons’ flimsy metal skins, most of which are only several fingernail widths thick.

The Baltic’s half-dozen bustling ports and commercial fishing industry may also suffer, jolting the economies of the nine nations bordering the sea. It is already heavily polluted by industrial wastes from adjacent countries.

The events leading to the present crisis began almost half a century ago when the United States, Britain and the Soviet Union met in secret after World War II to decide the fate of Nazi Germany’s enormous stockpile of unused chemical weapons, mainly skin irritants and nerve and tear gases.

Unwilling to pollute the air by incinerating them or to foul the ground by burying the poisonous stocks, the victorious powers decided to dump 500,000 tons of bombs, grenades and mines in the Atlantic. The weapons would then sink to the ocean floor, forgotten.

“The Allies were stuck with all these dangerous war gases, and they panicked that they might start to leak,” said Rune Erikson, a Greenpeace official in Sweden who works with the Baltic Sea campaign. “They just wanted to clean up everything and get rid of it as soon as possible.”

Lacking enough ships to carry the toxic cargo to the Atlantic from storage sites in eastern Germany, the Allies decided to toss most of the weapons in waters closer to Europe, although a few loads did make it to the ocean. Britain and America concentrated their dumping in the English Channel and along the coasts of Denmark and Sweden, pitching bombs overboard almost haphazardly and keeping no detailed maps about their location, Erikson said.

Meanwhile, the Soviet army, under Kremlin orders to complete dumping by Jan. 1, 1948, was working frantically during the last six months of 1947 to unload the Nazi gases into the Baltic. Bad weather so tossed Soviet ships around that the chemical weapons ended up widely scattered.

Boris Kazmin, technical director of a clean-the-Baltic project organized by Ocean Technology, a St. Petersburg consortium of academic and technical groups, estimates that the Soviet dumping took place in an area of 300 square miles southwest of Liepaja, a Latvian port, and over 3,000 square miles near Bornholm, a Danish island.

Besides pitching explosives, boxes and even plastic sacks filled with chemicals, the Allies sank up to 100 German ships loaded with war gases, Greenpeace’s Erikson said. Newly released documents indicate that dumping in the Baltic continued until 1965, especially from East Germany.

The 300,000 tons of chemical weapons now submerged in the Baltic Sea’s brownish-green waters contain enough active gases to kill 800 million people, or the entire population of Europe, Greenpeace asserted.

Angrily gesturing toward a large map outlining suspected dumping zones in red ink, Kazmin fumed: “In America and Britain, they didn’t care because the Baltic was far away from them. In the Kremlin, they just spit on future generations, on those who would suffer for their actions.”

Already, the chemicals have caused hundreds of injuries and dozens of deaths, Russian and Swedish environmentalists say. Hundreds of fishermen have suffered serious blister burns after catching grenades coated with oily chemical fluid in their nets. And yellow, waxy nuggets of phosphorus have washed up on Baltic Sea beaches, poisoning strollers who mistook them for pieces of amber.

But aside from these individual reports, scientists say they have no information on the broad, long-term ecological effects of the dumping. That is because the problem became public only two years ago and no research has yet been carried out.

No one knows, the environmentalists say, just how rusted the weapons have become after 45 years under water, or how much gas has already seeped into the Baltic. No one can predict how far the chemicals will spread, or how they will react in combination with one another and with salt water.

And, most critically, no one is sure how many fish have eaten the poisons, how many people have eaten carcinogenic fish, or whether health problems will emerge over the next few decades.

“Mutations in people might show up only in the third or fourth generation” of those exposed to the chemicals, said Yuri Semyonov, a professor at St. Petersburg’s Marine Technology Institute.

Hoping to find some answers, Russia is financing a $350,000, two-month expedition. Commanders from the Baltic Sea Fleet and the St. Petersburg Naval Base will lead a team of scientists and divers to examine the submerged weapons and perhaps bring some explosives to Russia for further research.

Russian President Boris N. Yeltsin appealed to President Bush during their summit in Washington last month to help organize a multinational cleanup campaign to save the Baltic. Although Russia will finance the first expedition, the country’s shattered economy cannot support the full cost of cleanup, which Ocean Technology estimates at $270 million.

“You could say that Chernobyl was our problem, but water is common to all nations,” said Semyonov, 45, who also serves as executive director of Ocean Technology. “You can’t divide the sea into buckets and say, ‘This part is ours, this part is yours.’ ”

Times staff writer Tamara Jones in Bonn and special correspondent Natalya Shul-

yakovskaya in St. Petersburg contributed to this story.

War Waste Woes

Uncertainty clouds the issue of how, finally, to deal with chemicals dumped in the Baltic Sea. Lifting rusted hulks of storage containers out of the water could spread chemicals throughout the sea--and could contaminate storage sites on land, as well. Europe has only one facility to destroy chemical weapons, an incinerator in Meunster, Germany. Some fear that burning war gases would disperse poisons over a wider area. Other proposals include covering weapons with liquid concrete, introducing bacteria into the sea to filter some of the poison and neutralizing underwater gases with other chemicals. Some even insist that the weapons simply should be allowed to rust in peace.