Mexican officials have removed the four-day air pollution alert after they deemed that ozone levels were back down to an acceptable level.
The alert was raised as ozone levels in Mexico City, the nation's highly populated capital, rose to dangerous levels. It was the first alert in 14 years and led to the restriction of traffic, emissions cutting at factories and many children remaining indoors.
City officials banned approximately 1.1 million vehicles in the central business district, and the government offered free public transport for the duration of the ban in order to reduce air pollution levels and lift the ban.
The surge in ozone concentration was declared an "environmental contingency" by the city government due to the ability of surging ozone concentrations to cause dangerous respiratory and heart problems.
During the course of the ban, the city's residents used scarves and masks to cover up their mouths and noses in order to prevent them from inhaling the toxic fumes and avoid health risks.
Officials claim that the ozone concentration had gone past the 190-point limit to 194. However, this number dropped to just 134 on March 17 after the aforementioned actions taken by the government, leading to the lift of the alert.
Mexico City is one of the worlds' most populated cities, with approximately 21 million residents and more than 5.5 million vehicles on the road per day.
Over the past few years, the city's government has been working to improve air quality after the United Nations declared the Mexican capital the most polluted city in the world back in the 1990s. Some of these measures include limiting the circulation of older vehicles that release more pollution and mandatory smog checks for car owners.
Despite these efforts over the years, the recent four-day pollution alert seems to have hindered this progress. Rafael Pacchiano, the federal environment secretary, claims that the city will be working on new standards to enforce pollution control, as well as find ways to make pollution detection a simpler process.
The World Health Organization (WHO) reports that approximately 12.6 million people died in 2012 due to poor environmental situations and that pollution contributes to one in every four deaths around the world.
