The heaviest pollution from NATO’s bombing this spring in Yugoslavia is concentrated in industrial areas, the U.N. Environmental Program is expected to say in a report released today. UNEP is urging Yugoslavia to immediately clean up several hot spots and is asking Western nations to provide clean-up funding. U.N. scientists say they found no evidence of widespread or long-term environmental catastrophe. But some scientists predict it will be decades before ecosystems recover from the thousands of tons of toxic chemicals threatening water supplies and contaminating fields. Radomir Mandic, director of Serbia’s Institute for Environmental Protection, claims NATO’s bombing campaign caused more than $3 billion in environmental damage.