A chimney emits smoke at a bauxite treatment plant operated by Compagnie des Bauxites de Guinee (CBG) in Kamsar, Guinea, on September 7, 2015. Local leaders have long expressed concerns about the impacts of the emissions on local air quality.

A chimney emits smoke at a bauxite treatment plant operated by Compagnie des Bauxites de Guinee (CBG) in Kamsar, Guinea, on September 7, 2015. Local leaders have long expressed concerns about the impacts of the emissions on local air quality.
© 2015 Waldo Swiegers/Bloomberg via Getty Images