Mexico City Air Hurting Kids

March 11, 1998

Any primary schoolteacher knows a disturbing fact of life in Mexico’s capital: children rarely use the color blue when they paint the sky in one of the world’s most polluted cities.

Most, like 8-year-old Hiram Gonzalez at a public school in the city’s crowded center, pick colors like gray, brown or even black to depict the pall that hangs over the city of roughly 18 million people. “The sky here is yucky color", Gonzalez said to the laughs of his classmates.

 But it is no laughing matter. Mexico City has just been decorated by the U.S.-based World Resources Institute with the insalubrious award of most dangerous city in the world for children in terms of air pollution.

Several times a year, when the sky darkens with pollution, Gonzalez and his fellow students are banned from playing outside and must sit indoors until the smog emergency passes.

Even Purifiers Don’t Always Help

The private Garfield primary school in the city’s south recently installed air purifiers in each classroom to protect children from the noxious air. But when air pollution levels rose in the past two winter months the purifiers did little good, and nearly all the school’s 37 students missed a few days with pulmonary-related illnesses such as bronchitis.

 “There were days last month when we were not sure we would have any students or teachers there were so many sick,” the school’s director, Fabiola Martinez, said.

The World Resources Institute study, funded by the World Health Organization, measured three important pollutants: sulfur dioxide, nitrogen dioxide and total suspended particulates (TSPs) — tiny particles of everything from dust to heavy metals that get deep in lung tissue and cause damage.

While some cities in China were much dirtier in pollutants such as TSPs, Mexico City was worst when combining all three measurements and taking into account the overall number of children under five exposed to the foul air, the study said.

Two Chinese Cities Close Behind

Beijing, Shanghai, Tehran and Calcutta follow Mexico City on the list of cities whose air poses greatest risk to children. Respiratory disease is now the leading cause of death for children worldwide, according to the study.

More than 80 percent of all deaths attributable to lung infections caused by air pollution occur in children younger than five in Third World countries like Mexico, it said.

The long-term impact is likely to be substantial, including diminished productivity from shortened lifespans and reduced lung capacity, more sick days, greater incidence of age-related chronic disease and a lower quality of life overall, it added.

In the short-term, pollution strikes hardest at children, who breathe faster and whose lungs are still developing, the elderly and those with lung trouble such as asthma.

“Air pollution reduces the lung’s ability to defend itself. We are even studying to determine if there is a change in the lung at the cellular level,” said Dr. Margarita Castillejos of the National Autonomous University.

A Generation of Increasing Filth

Sadly, Mexico City’s air has gone from among the world’s cleanest to among the dirtiest in the span of a generation. Novelist Carlos Fuentes’ first novel took place here in 1959 and was entitled “Where the air is clear” — a title he has said is ironic considering the city’s now-soupy environment.

Average visibility of some seven miles in the 1940s is down to about one mile. Snow-capped volcanoes that were once part of the landscape are now visible only rarely. And levels of almost any pollutant like nitrogen dioxide now regularly break international standards by two to three times.

Levels of ozone, a pollutant that protects us from solar radiation in the upper atmosphere but is dangerous to breathe, are twice as high here as the maximum allowed limit for one hour a year. And this occurs several hours per day every day.

“Mexico City’s air pollution is a criminal act against the city’s population,” said Humberto Bravo, a scientist at the National Autonomous University who has studied air pollution.

Geography Plays a Crucial Role

The city is in part a victim of its geography, sitting at the bottom of a bowl-shaped valley that prevents wind from sweeping away fumes from 3 million cars and 36,000 factories.

While Los Angeles has almost double the number of cars, those in Mexico City are on average 10 years old. Poor quality fuel and engines that run badly at the city’s 7,000-foot altitude make the problem here much worse.

The air also contains dried fecal matter from millions of gallons of sewage dumped near the city in open-air areas and from some 3 million stray dogs. Mexico City is one of the few places in the world you can inhale a gastrointestinal disease like hepatitis or dysentery.

 Bravo said state-run oil monopoly Pemex could reformulate its fuel to meet California’s strict emissions standards but has shied away from the project due to the price tag: $4.9 billion. “That may sound like a lot, but how many billions will it save in future health care costs?” Bravo asked.

Billions Spent to Combat Conditions

Mexico has spent at least $5 billion trying to clean the capital’s air this decade, replacing outdated diesel buses, closing down a city oil refinery and reforesting some of the denuded hills nearby. But many say the government needs to do much more, such as improving Pemex fuels, strictly enforcing anti-pollution laws for industry and promoting development in other areas of the country.

 “There is a lack of leadership by the authorities. Each public official simply sits on his hands and hopes nothing too bad will happen on his watch,” Bravo said.

In the past few months, doctors estimated as many as half of all Mexico City residents fell ill with flu-like symptoms. The difference was the symptoms lasted at least several weeks, not several days. Even President Ernesto Zedillo publicly complained recently that his “cold” has lasted for weeks.

“The air pollution does not cause the cold but it certainly allows it to last much longer by weakening the immune system,” said Dr. Luis Lamm, a private Mexico City physician. “This epidemic of flu is a wake-up call for our pollution problem,” he said.