Ключевые слова: air, area, building, chemical, chimney, city, cloud, coal, construction, contamination, danger, dark, dioxide, dirty, energy, environment, environmental, factory, fog, fumes, global, grunge, impurity, industrial, industry, manufacturing, old, pipe, plant, polluted, pollution, power, problem, rain, rusty, sepia, sky, smog, smoke, steam, steel, structure, technology, tower, toxic, urban, vintage, warming, waste, water,