Taking control of air pollution in Mexico city
August 04, 2011
IDRC / D. Marchand
In 1992, the United Nations described Mexico City’s air as the most polluted on the planet. Six years later, that air earned Mexico the reputation of “the most dangerous city in the world for children” — a reputation Mexico has been working hard to improve. But despite more than a decade of stringent pollution control measures, a haze hangs over the city most days, obscuring the surrounding snow-capped mountains and endangering the health of its inhabitants.
Many factors have contributed to this situation: industrial growth, a population boom (from three million in 1950 to some 20 million today), and the proliferation of vehicles. More than 3.5 million vehicles — 30% of them more than 20 years old — now ply the city streets.
Mexico city’s geographic disadvantage
Geography conspires with human activity to produce a poisonous scenario. Located in the crater of an extinct volcano, Mexico City is about 2,240 metres above sea level. The lower atmospheric oxygen levels at this altitude cause incomplete fuel combustion in engines and higher emissions of carbon monoxide and other compounds. Intense sunlight turns these into higher than normal smog levels. In turn, the smog prevents the sun from heating the atmosphere enough to penetrate the inversion layer blanketing the city.
Solving this problem has been a priority of the Metropolitan Environmental Commission. Recent efforts to curb emissions have been relatively successful. In the 1990s, for instance, the government introduced air quality improvement programs — PIICA and PROAIRE — that include a rotating one-weekday ban on private car use. On days of high pollution, the ban extends to every second day and some manufacturing activities are curtailed. In addition, car owners must have their vehicles certified every six months. But if lead, carbon monoxide, and sulphur dioxide are now under control, pollution levels of other contaminants are still far above air quality standards.
A closer look at pollution
When PROAIRE concluded in 2000, environmental authorities undertook a longer, ambitious air quality improvement program — PROAIRE 2002-2010. However, accurate measures were needed to determine how improving air quality would improve health and reduce health expenditures so that new pollution control strategies could be evaluated. A number of questions also needed to be answered about the relationship between the city’s inhabitants and air pollution: How do people perceive pollution? How does it affect them? What are they willing to do or pay for cleaner air? How can they be motivated to help solve it? [See related sidebar: What do Mexicans think? Don’t blame me!]
The Mexico City Government set out to answer these questions, with support from Canada’s International Development Research Centre (IDRC) and the Netherlands Trust Fund, through the World Bank and the Pan American Health Organization.
Examining the impact on health
The researchers focused on health hazards posed by the most serious pollutants: PM10 and ozone. PM10 comes from various sources, including road construction and dust, diesel trucks and buses, forest fires, and the open-air burning of refuse. Both pollutants can irritate eyes, cause or aggravate respiratory and cardiovascular ailments, and lead to premature death.
“It’s not air pollution that kills people but some people die sooner than they would otherwise,” says biologist Roberto Muñoz Cruz, sub-director of information and analysis at Mexico City’s atmospheric monitoring system, part of the Secretaria del Medio Ambiente. The Secretaria coordinated the project in collaboration with the National Centre for Environmental Health, the non-governmental organization GRECO, and the Women’s Institute of Mexico City.
Researchers from eight academic, governmental, donor, and non-governmental organizations in Holland, Mexico, and the US contributed to national and international health studies on ozone and PM10. Surveys also determined people’s perceptions of the pollution problem.
A population exposure model was then developed, using data from Mexico’s sophisticated air monitoring network. The study estimated that pollution levels in 2010 will be much the same as in the late 1990s when ozone levels exceeded standards on almost 90% of days and PM10 exceeded standards on 30-50% of days.
The costs of pollution
Earlier efforts to assess the costs of pollution in Mexico City had focused on direct medical costs such as medicines and hospital visits and on productivity losses. This study, however, sought to provide a more comprehensive picture. A transdisciplinary research team assessed a range of health benefits and “savings,” including people’s willingness to pay for better health and a potentially longer life. Communications and social participation specialists worked to understand peoples’ perceptions and assess indirect costs because, as Muñoz explains, “not only do people who get sick lose days from work, but also mothers who stay home to take care of the children who get sick.”
The research concluded that reducing PM10 would yield the greatest health and financial benefits. Reducing both ozone and PM10 by just 10% would result in average “savings” of US $760 million a year. In human terms that would translate into 33,287 fewer emergency room visits in 2010 and 4,188 fewer hospital admissions for respiratory distress. In addition, it would lead to 266 fewer infant deaths a year.
This detailed information provided the scientific underpinning of PROAIRE 2002-2010, which calls for almost US $15 billion of public and private investments in air quality improvement projects.
If people largely cause air pollution, they must also be involved in cleaning it up. Making people part of the solution obviously requires new training and information programs. This phase of the project, carried out through the Women’s Institute, targeted the women who come to the Integrated Women Support Centres, as well as local political and social leaders. Both groups were chosen because of their spheres of influence, explains Muñoz.
The topics covered were defined in collaboration with community members who were not only interested in quality control but also in improving their social and economic situation, in equitable sharing of responsibilities, and in creating networks for communities to work together. Empowering women to foster social and political changes was a key objective, as was increasing recognition of their decision-making role in the family and community.
Promoting community capacity to solve problems together was a new endeavour for the government, says Muñoz. Six areas were chosen to test the training program: three poor communities in an outlying mountainous region, and three more centrally located communities where green spaces have given way to concrete. Working with researchers from the project’s first two modules and in collaboration with members of the women’s centres, the Women’s Institute technicians translated the technical data into language and actions that everyone could easily understand.
Through games and participatory activities, promoters helped forge a sense of community. Workshops then helped participants understand the issues, identify community problems and needs, and determine their role in helping solve them. Attention was given to distinguishing the roles of men and women in preserving both environment and health, in the home and in the neighbourhood.
And because community participation is tied to obtaining immediate benefits, the issue of sustainable consumption was added to motivate better practices and lifestyles, explains Muñoz — how to save money by using environmentally friendly products, alternative technologies and fuels, and bulk purchasing, for example.
Finally, individual and collective actions were defined and a support network created to help community members at higher risk — children and the elderly, or those with chronic diseases. Throughout, the main message was “This is preventable. You can take action.”
There is little doubt that this project has helped shape Mexico City’s long-term air quality policy and programs. And although this type of joint initiative is new, says Muñoz, it bodes well for intergovernmental cooperation to attack the problem. It is also a step forward in developing ways to examine the entire cycle and involve populations.
What do Mexicans think? Don’t blame me!
The original PROAIRE programs recognized that people must be involved in any solution and included various formal and informal programs to inform people about the problem and invite them to action. “It recognized that a cultural change was needed to modify the society-city-environment relation,” says Muñoz.
But in a community as large, as socially and culturally diverse as Mexico City, that proved no easy task. As questionnaires administered by the research team to close to 4,000 residents in all sectors or delegations of the city showed, close to 30% believe the government’s motives in seeking to reduce air pollution to be self-serving. More than 30% also think that the government’s online air quality reports are false.
In fact, says Muñoz, “we found that most people don’t even consult the official information.” They base their perceptions on what they experience: breathing in car exhaust in narrow, clogged, downtown streets, for instance. “If people see the mountains, they say it’s a good day. If they can’t, they say pollution is high.”
Close to 40% could not identify any of the government programs to improve air quality. The remainder considered them necessary evils — restrictions rather than preventive measures.
Equally distressing, although everyone recognizes the pollution problem, “people don’t see their responsibility for it,” says Muñoz. A high percentage blame factories. A smaller number point to vehicle exhaust, which, as Borja points out, is the source of 75% of emissions. “They say that the problem is in other areas — in the northwest, in the downtown, not where I live,” adds Roberto Muñoz. “Other people are mainly responsible: my neighbours, maybe, but not me, not my car. My family and lifestyle are not to blame.”
And what do people do to cope with pollution? Usually nothing. What are they prepared to do? Very little. And this, says Muñoz, despite the fact that almost all recognize that air pollution is harmful to health and is particularly hazardous for children.
Focus groups discussions with men and women at all age levels confirmed that perceptions of the pollution problem were largely subjective. They also confirmed that most are not willing to allocate time or money — or to sacrifice comfort — to alleviate the problem. “It seems that the participation of society is limited to complying with programs,” says Muñoz.
This, he says, clearly points to the need for better communication about government programs’ successes in improving air quality. Better communication of risks is also needed. “It’s clear that information needs to be targeted to individual groups — drivers, women, children,” he says. “People need information in a succinct form, they need a consistent message, over a long period.”
Michelle Hibler is a writer in IDRC’s Communications Division.