MEXICO CITY, MEXICO - APRIL 5: Heavy mist blankets Mexico City on April 5, 2016. in Mexico City, Mexico. Authorities have declared a pollution alert after smog rose to one and a half times acceptable limits. In response, the city's government is taking one million old and new cars alike off the road each day of the week for the next three months in an effort to reduce the alarming pollution levels. (Photo by Miguel Tovar/LatinContent via Getty Images)
