Communists dried the Aral sea, turning an absolute huge area into a toxic dust desert.

It used to be surrounded by small fishing towns. People either left when the sea died, or became sick or died from diseases and cancers. As the sea evaporated, the initially-faint traces of pesticides and pollution in the water concentrated and deposited on the dried salty ground. When there is wind, the dust blows everywhere and people breathe that shit.

Mind you the people benefiting from diverting the water from the rivers never stopped after the fall of Communism.

And when the wet season allows some run-off to reach the dried bassin, it brings a fresh dump of toxic chemicals.