Officially, the ravages of pollution in Eastern Europe were classified information, Communism's dirtiest secret. For more than 40 years, as the devastation mounted, only a few officials kept track of the toll. The people could see, smell and sometimes choke on contaminated air and water. They could watch the grime accumulate on their homes and see the vegetation die. But they could not speak about it or protest too loudly, lest they be harassed as dangerous dissidents.
Only now, as democratic revolutions take hold, is the full extent of Eastern Europe's stunning ecological disaster emerging. Flying over Poland, Czechoslovakia and East...