Mexico City has a toxic “sacrifice zone” where cancer proliferates

Doña Agustina lived on that corner, who died of stomach cancer, as did Coco, her neighbor across the street.

Later lived Eva, whose death from a ruptured tumor in her throat left her autistic son helpless.

Colon cancer took Doña Juanita, who entered the hospital on a Friday and died the following Monday.

And Estela lived there until about two years ago, when lung cancer spread throughout her body.

At the end of his tour of his hometown, General Pedro María Anaya, Uribe had drawn up an incomplete but gloomy assessment:

at least 42 cancer-related deaths, 15 survivors and six active cases, all concentrated in a few blocks.

“It’s a lot of pain,” said Uribe, 45, a former seamstress who turned to activism after seeing her town besieged by unexplained illnesses.

“It is not normal to have so many sick people in a community.”

For many residents of the more than 20 communities surrounding the reservoir known as the Endhó dam, In the Mexican state of Hidalgo, cancer is just another symptom of a crisis decades in the making.

In the 1970s, federal authorities quietly diverted stormwater and wastewater from Mexico City to the region, effectively turning it into a dumping ground for more than 20 million people.

Effluents from a heavy industry corridor—which includes more than 100 factories and an oil refinery that supplies Mexico City and other states—have exacerbated the crisis, as the vast majority of those plants discharge their untreated waste in the Tula River, which flows into the Endhó.

The result has turned the reservoir into what residents call the largest sewer in the world.

The United Nations special rapporteur on toxic substances and human rights has classified the Endho basin as one of the “sacrifice zones” oldest in Mexico, an area where local health and ecosystems are intentionally compromised to benefit the capital and its surrounding industries.

Sacrifice zones are a counterpart to modern urban planning.

Areas where some lose so that the majority prosper.

This pattern is seen around the world, from Louisiana’s “Cancer Corridor” and the steel mills of Italy, to the tar sands of Canada and the Endhó Dam in Mexico.

Around the reservoir, the air is thick with sulfur and putrefaction.

White clouds of chemical foam float next to houses and roads, while the large amount of organic waste in the water feeds an unstoppable carpet of aquatic weeds.

“What we experience day after day is hell,” said Magnolia Sánchez, 51, a resident of San Mateo La Curva, another riverside community, whose cousin Maira died of breast cancer.

Older residents still remember when the contaminated water arrived without warning.

Feliza Camacho was a newlywed in 1972 when she noticed that the reservoir was becoming cloudy and smelly.

Then the first victims arrived.

“The lake was white with dead fish,” said Camacho, 73.

The decision to channel sewage and industrial waste from Mexico City into the Endhó reservoir was initially considered a win-win.

As the capital grew, engineers desperate to protect the city from catastrophic flooding also realized that the reservoir’s waters, rich in organic nutrients from wastewater, could serve as free irrigation and fertilizer for the naturally arid valley.

Decades later, the massive influx of nutrients has sustained the region’s agricultural boom, while transforming the Endhó into a environmentally dead zone.

The microbes have depleted the prey’s oxygen reserves.

Aquatic life has disappeared.

In 2024, a dense layer of invasive water hyacinth covered the surface, growing more than 27 times its initial size in just a few months, according to government estimates.

The labyrinth of cracks, nooks and holes among the tangled vegetation has turned Endhó into a prolific mosquito factory.

When night falls, people lock themselves in their homes.

Barbecues and quinceañera parties have been canceled due to the pests.

Families burn cardboard indoors, hoping the smoke will scare away the insects, and buy up to three cans of insecticide a week, which is a big expense.

The bedroom walls are splattered with dried blood, traces of the nightly battle against these bugs.

“We live on the edge. Being locked up like this, we are becoming aggressive. I see it in my own children; I see it in myself,” said Pablo Tinajero, 59, a community leader in Santa María Daxthó, a town next to the dam.

At a nearby elementary school, Daniela Álvarez, a teacher and principal, struggles to keep her students’ attention.

Children constantly move in their seats to scare away mosquitoes, he explains, and going to the bathroom, where these insects congregate, has become a source of fear.

Even Álvarez, 41, avoids removing books from the shelves for fear of releasing hidden insects.

“We have normalized pollution, bad air and contaminated water,” he said.

“But normalizing a plague is going too far. We shouldn’t have to teach our children that this is normal.”

When Leticia Sánchez González’s right breast swelled last year, the pain was so intense that she had to quit both of her jobs.

The doctors told him not to worry, he said.

It was probably an infection.

In June, new tests confirmed their suspicions:

Her oncologist prescribed six cycles of chemotherapy, followed by a mastectomy.

“A lot of people are getting sick now,” said Sánchez, 48, who lives near the dam in Santa Ana Ahuehuepan.

“You have it, but so does your neighbor.”

The true extent of the disease is unknown.

According to raw data from the Mexican statistical agency, cancer mortality rates in Tula de Allende — one of the two municipalities where the dam is located — have exceeded the national average every year since 2016, sometimes being more than 50% higher than the rest of the country.

In the neighboring municipality of Tepetitlán, mortality rates from kidney failure and urinary tract diseases have consistently exceeded the national average, sometimes doubling it.

However, there is no public health data on the towns located in the vicinity of the dam.

The results of the census carried out by state and federal health brigades in 2024 were never made public.

Additionally, the government has refused to fund epidemiological studies in the region, according to two researchers who spoke on condition of anonymity for fear of losing public funding.

Without that evidence, it is virtually impossible to determine whether the increase in cancer cases is actually due to pollutants in Endhó, some other factor, or chance.

But for others, there is a clear connection between the contaminated waters of the Endhó and the public health disaster.

“The pattern is unequivocal,” said Juan Francisco Martínez, former director of epidemiological surveillance of Hidalgo.

“There is an obvious, strong and coherent correlation, although there are no epidemiological studies that demonstrate causality.”

Mexico’s Health Ministry and the country’s health regulatory agency did not respond to a list of detailed questions.

As for residents, they say the proof they need is in their own backyards.

After the arrival of waste from Mexico City, the communities dug seven wells in search of drinking water, since the reservoir was becoming contaminated.

However, for almost 20 years, government studies have repeatedly confirmed that wells – the main source of drinking water – are contaminated.

According to reports from the federal water authority of Mexico, consulted by the Times, they have been found arsenic, mercury and lead in wellss, exceeding the maximum limits established by Mexican safety standards.

Toxic levels of nitrates and fecal bacteriaas well as industrial solvents and byproducts of the petrochemical industry.

In 2024, an official report detected an identical chemical and molecular fingerprint between the reservoir and the local drinking water supply, concluding that the toxic substance from Endhó had leaked into the city’s wells.

But Mayela Godínez, an official with Mexico’s water authority, dismissed that investigation as erroneous, and insisted that the agency’s technicians had assured her that the well water “is not contaminated, that its quality is good.”

However, change can be slow.

The former president Andrés Manuel López Obrador signed a decree in 2024 that legally required the government to remedy decades of environmental neglect at the dam, eliminating weeds and mosquitoes.

So far, the government has fumigated 27 communities and extracted the equivalent of 42 Olympic swimming pools of water hyacinth.

But the plan, which authorities called “the most important act of environmental justice in the country’s history,” is hollow, according to critics.

The decree prohibited the allocation of new funds for cleaning the dam, drawing instead on already depleted public budgets.

Efforts to treat wastewater are met with strong resistance from farmers who rely on the nutrient-rich runoff as fertilizer for their crops.

And, crucially, the program excludes public health initiatives.

“Once the environment is restored, our health will improve, they tell us,” said Uribe, the activist.

«It is an insult to our suffering. Cancer doesn’t wait. “Diseases do not wait.”