Why did air quality improve in Saxony-Anhalt after German reunification?

Following German reunification in 1990, air quality in Saxony-Anhalt improved dramatically due to a significant reduction in economic activity, particularly within the state's industrial sectors.1

Specifically, the region experienced a major decline in chemical and lignite production. Between 1990 and the early 2000s, lignite production in the Central German Coalfield dropped by more than three-fourths, and employment in that sector fell by more than nine-tenths. This shift away from heavy industrial reliance, which had previously caused significant environmental degradation under the East German system, directly contributed to the notable improvement in air quality across the state.12