Not really lens pollution. This is a typical winter view of my hometown from above. Due to the high concentration of fine dust particles mainly from coal and wood heating, along with heavy car traffic - thick, foul-smelling fog often engulfs large parts of the city. The cold polluted air becomes trapped in the lower atmosphere, but when you climb one of the nearby peaks of Vitosha Mountain, the phenomenon is clearly visible even without any special equipment. The different glow colors come from the street lighting: some areas use yellow/orange sodium lamps, while others use green-tinted lighting.