PANCEVO, Yugoslavia -- Near bombed oil refineries and crumpled petrochemical plants, Petar Danilov baited his hook with bread dough and fished for carp in a canal polluted with vinyl chloride, mercury and ammonia.
"I'm eating these fish, but I'm not feeding them to my kids," said Danilov, standing in wading boots and watching a bobber drift on the murky water flowing into the Danube River. "It will take years to know the long-term damage to the Danube. In the meantime, I'll fish."
The NATO missiles and bombs that hammered Yugoslav President Slobodan Milosevic's country last spring caused widespread damage to the nation's environment.
Yugoslav and international scientists predict it will be decades before ecosystems recover from the thousands of tons of toxic chemicals threatening water supplies and contaminating fields.
"Our mountains are packed with war waste and bomb fragments. Tons of mercury -- like an environmental time bomb -- have settled at the bottom of the Danube," said Vojislav Vasic, an anti-government scientist and president of Yugoslavia's Natural Museum in Belgrade. "These consequences are not spectacular or easy to see right now. But they are quiet ones that will be with us for years."
A report to be released Thursday by the United Nations Environment Program is expected to conclude that Yugoslavia's heaviest war pollution is confined to industrial cities. Site investigations by teams of U.N. scientists found no evidence of widespread or long-term catastrophe. But UNEP urged the Yugoslavia government to immediately clean up several "hot spots."
One is in Pancevo, where NATO strikes on oil refineries, petrochemical plants and fertilizer factories released mercury and other carcinogens over the ground and into the 1.2-mile-long canal leading to the Danube.
Another major problem is a brew of poisonous waste, including dioxin and polychlorinated biphenyls (PCBs), leaking from the Zastava car factory in Kragujevac.
This contamination poses a "serious threat to human health," according to Pekka Haavisto, a former Finnish environment minister and head of the UNEP team in charge of the Balkans. UNEP is also troubled by toxic gases escaping from a copper plant in the city of Bor and from unexploded bombs in national parks and recreation areas.
The United Nations is asking western countries to provide money for environmental safeguards, but NATO countries are split over sending reconstruction aid as long as Milosevic is in power.
During 78 days of NATO bombing, much of Yugoslavia was a wasteland of leeching chemicals, shattered trees and cratered fields.
Miles-long oil slicks shimmered down the Danube through Bulgaria and into the Black Sea. Towering clouds spawned acid rain from Romania to Greece. Depleted uranium from 30 mm armor-piercing rounds fired by A-10 Warthog planes drifted invisibly through the air.
An initial investigation by the United Nations and the Swedish Radiation Institute found no dangerous radioactivity from weapons containing depleted uranium. NATO and the Pentagon have also played down such health risks from the conflict. For years, U.S. veterans groups have said that depleted uranium caused cancer and other illnesses after its use in munitions during the 1991 Persian Gulf war.
The list of pollutants that spilled near or into the Danube read like an almanac of poisonous chemicals: 1,000 tons of ammonia, 1,400 tons of ethylene dichloride, 1,000 tons of hydrogen chloride, 8 tons of mercury and more than 40,000 tons of crude oil, according to Yugoslav scientists and independent environmentalists.
"The fish kills were so large in the Danube that they seemed like big carpets on the water," said Vasic. "The bombing upset the migratory pattern of birds, and habitats for endangered species are damaged.
"Imperial eagles had two nests in Yugoslavia, but this year there are none, and that's horrible."
Tons of other chemicals burned, releasing clouds through Pancevo and other cities. On April 18, Pancevo's Health Protection Institute detected fumes of cancer-causing vinyl chloride monomers that were 10,000 times higher than safe industrial levels. Several scientists said NATO bombs worsened an environment already fouled by Yugoslavia's weak industrial regulations and years of economic sanctions.
"These chemicals cause skin cancer, skin disease and genetic problems," said Predrag Jaksic, a biologist who fought with the Yugoslav Army in Kosovo and heads the government team preparing an environmental damage assessment for UNEP. "They are polluting the environment now and will eventually work their way through the chain and into humans. That will be the long-term catastrophe."
Bombs and missiles struck hundreds of targets -- from fertilizer plants to shoe factories to cow breeding farms -- and scores of pollutants might be seeping into springs and underground drinking water tables across the nation.