Why So Many Latin American Schools Sit Near Toxic Sites

Latin America · Environment

A new map of toxic land across the developing world lands hard on Latin America: from Bogotá to Lima, a large share of city schools sit within a few kilometres of documented contaminated sites — and the one big capital that looks clean, Mexico City, mostly looks that way because of where the record-keeping stops.

What the new map shows

The research comes from the Center for Global Development, a Washington and London think tank, and its education researcher Lee Crawfurd. In a working paper titled Schools in the Shadow of Toxic Sites, he overlaid maps of documented polluted land onto the locations of millions of schools.

The sites are tainted by lead, mercury, arsenic and pesticides. The paper covers 17 low- and middle-income countries.

The headline is stark. More than 250,000 schools, roughly one in ten, sit within five kilometres of a documented contaminated site.

Because urban schools tend to be larger, the pupil count is worse still. Across the seven countries with enrolment data, more than 12 percent of children — over 43 million of them — attend a school that close to a known site.

In the Philippines, just 9 percent of schools are near a site, yet those schools hold 27 percent of the country’s pupils. Crawfurd has also published an interactive map plotting every school and site.

Latin America’s capitals are heavily exposed

The clearest pattern is urban. In nine of the ten capitals studied, the share of schools near a contaminated site runs well above the national average.

The extremes sit in Asia and Africa — New Delhi at 91 percent, Metro Manila at 86 percent, Nairobi at 72 percent. But Latin America’s big capitals are squarely on the same list.

In Bogotá, 55 percent of schools fall within five kilometres of a documented site. In Buenos Aires it is 46 percent, and in Lima 38 percent.

For a region that pictures toxic land as a problem of distant mining towns, that relocates it to the heart of the cities. It is where most children actually live and study.

The striking exception is Mexico City, where almost no school sits inside the band. That is not because the capital is clean — Mexico’s catalogued sites simply cluster elsewhere, in the industrial corridors of Estado de México, Hidalgo and the Bajío.

It is the first hint of the study’s deeper lesson. These maps trace where records exist as much as where pollution does.

The Brazil twist: counting, not contamination

Nowhere is that lesson clearer than in Brazil. The global inventory behind the study is the Toxic Sites Identification Program, or TSIP, the best worldwide database of contaminated land in developing countries.

By the author’s own account, it is far from complete. In his summary of the findings, Crawfurd notes that TSIP lists only 155 contaminated sites for the whole of Brazil.

The state of São Paulo, by contrast, keeps its own register through its environmental agency CETESB. That single state records 1,270 sites — roughly eight times what the global database holds for the entire country.

CETESB has published this kind of monitoring data since 2002, a discipline few other Brazilian states match. The natural misreading is that São Paulo is unusually dirty.

The truth is the reverse: São Paulo counts, and most of Brazil does not. One Ghanaian study cited in the paper estimates TSIP captures only about one site in eight.

So the blanks on the map are not clean ground. They are missing records, and Latin America’s real exposure is almost certainly higher than any figure here suggests.

Who is most exposed, and the private-school surprise

The map also overturns a rich-world assumption. In wealthy countries pollution falls hardest on poorer pupils, but across the developing world the study finds the opposite.

The reason is that contamination concentrates in the cities where richer families live. That also explains the most counter-intuitive result.

In all eight countries with the data, including Brazil, private schools are more likely than public ones to sit near a polluted site. In Ghana the gap is 41 percent against 18 percent.

Account for urban location, though, and more than half of that gap disappears. Industry, wealth and private schooling simply share the same city centres.

What the study does not claim

The caveat matters as much as the numbers. Crawfurd is explicit that the work measures proximity, not exposure or health impacts.

Being near a listed site is not proof any child has been harmed. Five kilometres is also a wide radius, and the paper notes the most serious effects tend to occur within a few hundred metres.

The findings flag schools that might warrant a closer environmental look. They are not confirmed cases of damage.

Why a foreign reader should care

For an investor or executive weighing the region, the lesson is about transparency, not panic. A country that documents its environmental problems well can look worse on paper than one that simply does not measure.

That is a trap when comparing risk across Latin American markets. For families, the practical takeaway is calmer than the headline.

The data points to where more local testing would be wise. Crawfurd suggests modest steps — basic hand hygiene and educating students and parents — rather than alarm about any single school.

He also notes that schools can push for change. A teachers’ union helped force the lead-poisoning crisis in Flint, Michigan into the open, and unions across Latin America could do the same.

Frequently asked questions

Which capital cities have the most schools near toxic sites?

Proximity is highest in big capitals like New Delhi (91%), Metro Manila (86%) and Nairobi (72%). In Latin America, 55 percent of schools in Bogotá, 46 percent in Buenos Aires and 38 percent in Lima sit near a documented site, while Mexico City is the exception with almost none.

What did the study actually measure?

It mapped how many schools sit within five kilometres of a documented polluted site across 17 developing countries. The Center for Global Development stresses it measured distance only, not exposure, and that patchy records make the totals a floor.

Why does São Paulo show so many more sites than the rest of Brazil?

Because São Paulo’s agency CETESB has catalogued contaminated land since 2002, while most states publish little. The global TSIP database lists 155 sites for all of Brazil against São Paulo’s 1,270, which the study reads as better record-keeping rather than worse pollution.

Are private schools really more exposed?

In all eight countries with data, including Brazil, private schools were more likely to sit near a polluted site — in Ghana, 41 percent versus 18 percent for public schools. Most of the gap reflects industry, wealth and private schools sharing the same urban areas.