The Eastern-bloc countries, along with the Soviet Union were the most polluted places on the planet.
Liberals are very selective in their "environmentalism." China and the Soviet Union were probably the biggest polluters - continuing to pour sewage and industrial waste raw into rivers, lakes, and harbors while ours were cleaning up in the 70's and 80's. Yet in the 1970's and 80's the "Earth Day" types only complained about American pollution. I guess they believed that industrialization and pollution in America were reactionary while Chinese and Soviet pollution were just part and parcel of the radical revolution.
Similarly, environmentalist radicals like Bill Nye complain about "overpopulation" in America and Europe, and urge people in developed country to have fewer children or none at all, this in spite of the fact that most developed countries have zero or negative population growth. Bill Nye wouldn't dare recommend fewer children in Sub-Saharan Africa or other Third World countries (this in spite of the fact that population growth their is sky-high and doesn't have the economy or infrastructure to support it). Complaining about Third World overpopulation and pollution would be "racist."