Air pollution envelops central Mexico

Children wear face masks while participating in a cultural event on Mexico City’s central square, or Zocalo. A smoky haze that has blanketed the capital for the past week is fraying nerves, spurring health worries and generating criticism of elected officials.

(Alfredo Estrella / AFP/Getty Images)

May 18, 2019 9:36 AM PT

Smog blankets the skyline of Mexico City, where schools have been closed and outdoor events, including professional soccer games, have been canceled under an emergency decree because of the poor air quality.

(Marco Ugarte / Associated Press)

A cyclist delivering food wears a face mask in Mexico City.

(Pedro Pardo / AFP/Getty Images)

Visibility is poor above Mexico City, where people have been advised to stay indoors and avoid using their vehicles while extreme smog conditions persist.

(Toya Sarno Jordan / Getty Images)