The high ozone levels that led Mexico City’s government to declare a state of emergency this Monday, March 14 are due to insufficient public transit services, according to experts in air pollution. The ozone levels are the highest in 13 years. The experts urge that schools be closed until the state of emergency is lifted.
The city is under a Phase 1 Contingency, the second-highest level of alert on the official scale created on Jan. 1, 2005. The current environmental alert is the first declared in Mexico because of ozone since Sept. 18, 2002, according to the city’s records.
— Ces M. González (@emigo04) March 15, 2016
Chemical engineer Carlos Álvarez Flores said that at least 70 percent of air pollution in the Valley of Mexico corresponds to the kinds of pollutants emitted by motor vehicles.
He called the ozone levels “bad news” because air quality had been improving in recent years. He added that while motorists struggle to comply with emissions restrictions, which are becoming stricter and stricter, the city government does not match that effort.
The measures in the Contingency Plan include decreasing vehicular transit and halting industrial activities that use fuel or volatile products or generate emissions.
In a series of press releases, city environmental authorities advised that as of Monday, people should avoid walking in open spaces. They also advised people to stay inside between 1 p.m. and 7 p.m. on Tuesday, March 15, and avoid outdoor physical exercise to prevent respiratory diseases.
Climate change researcher Dr. Antonio Ordoñez believes that poor quality of roads, as well as the fact that newer cars are not designed for the low speeds required by recently enacted transit laws, are also key factors that contributed to the growth in air pollution.
The 2012 Global Burden of Disease study, which measures loss of health due to pollution in 187 countries, shows that pollution caused 20,500 premature deaths in Mexico, and more than 2.3 million worldwide.
Particulate matter is considered to be one of the most dangerous pollutants. According to the World Health Organization (WHO), chronic exposure to particulate matter increases the risk of cardiovascular diseases and lung cancer.
In Mexico, the official limit on PM10 particles, or particles with diameters smaller than 10 micrometers, is 140 percent of the limit recommended by the WHO. PM10 particles are responsible for 50 percent of pneumonia deaths in children under 5.
In general, particulate matter and other pollutants inflame the respiratory tracts and the lungs, weaken immune responses and reduce the oxygenation capacities of the blood.