Mexico moves to combat pollution following Guardian investigations | America’s toxic trade

The Mexican government has announced it will apply a wide range of tactics to combat industrial pollution, from fines of $4.8 million against a US hazardous waste processing plant to the deployment of a new industrial air monitoring system, following investigations by the Guardian and Quinto Elemento Lab, a Mexican investigative unit.

These stories revealed high levels of heavy metal contamination in the neighborhood around the Zinc Nacional factory, in the Monterrey metropolitan area, and showed the broader scale of industrial pollution in the region, linked to Monterrey’s role in manufacturing and recycling products for the U.S. market.

Investigations found that the facilities released more toxic heavy metals into the city’s air than the totals reported in many U.S. states, and more carbon dioxide than nearly half the world’s countries.

In an announcement last week, the government said it would establish a new atmospheric monitoring network for industry, “the first of its kind in Latin America.” The system will measure emissions from industry, including heavy metals.

Mariana Boy Tamborrell, Mexico’s federal environmental protection prosecutor, said the latest measures represent a new wave of measures against industrial pollution in Mexico. They originated when the first articles were published in early 2025 and include Zinc Nacional agreeing to address environmental damage, according to its agency.

“The work we have done over the past year with Zinc Nacional represents a watershed moment in how we monitor and inspect industries’ regulatory compliance,” she said in a statement.

Details of the new air monitoring system remain unclear and the agency did not provide information at the time of publication. It is unclear whether this will affect Monterrey or the entire country.

Additionally, the country’s top environmental regulator announced it was updating air and soil contamination standards, some of which have not been revised in decades.

Martín Soto Jiménez, a prominent toxicology researcher at the Universidad Nacional Autónoma de México (Unam), who conducted soil sampling around Zinc Nacional in collaboration with the Guardian and the Quinto Elemento Lab, said the new efforts to hold the company accountable for the cleanup set a precedent.

“This agreement constitutes a historic step forward for environmental justice in Mexico,” he said in a written response to questions from journalists.

“The creation of an atmospheric monitoring network is one of the most valuable elements of the agreement. To be useful, it must make data public in real time. [and] allow citizens and scientists to access and analyze information.

Zinc Nacional, a Mexican company that imports highly toxic dust from the recycling of old cars and appliances by the U.S. steel industry, must take 24 corrective actions in addition to the fine.

The company is to relocate some of its operations to a new factory outside the residential areas of densely populated Monterrey and build new containment and water treatment facilities. It must remediate contaminated land, reforest 12 acres (5 hectares) and monitor future emissions.

In a statement to the Guardian and Quinto Elemento Lab, Zinc Nacional acknowledged that there was some contamination on its land, which it said was associated with a company that previously operated on the site. It said its “emissions were identified as being well below regulatory parameters, confirming the effectiveness of our dust control and collection systems”.

No contamination is dispersed into the air or carried to nearby bodies of water by rain, he said.

“Thanks to all these actions, we will reduce the environmental footprint of our operations, continue to strengthen local employment, [and] expand green spaces,” he said in a press release.

In the past, Zinc Nacional has disputed the results of soil sampling in the community around its plant, raising doubts about how the study was done and saying it did not prove heavy metals came from the company’s plant.

Some neighbors expressed disappointment with the government’s announcement, saying it focused on contamination within the plant’s boundaries but did not address concerns about health effects and heavy metals in the surrounding neighborhood.

Soil samples taken around the plant for the articles showed heavy metals, such as lead, cadmium and arsenic, inside and outside schools and homes. An elementary school had lead levels 1,760 times higher than would be considered a human health risk in the United States.

“I think [the government] failed to properly assess the needs of vulnerable communities adjacent to the company,” said Ricardo González, one of six neighbors who spoke with reporters and became involved in efforts to demand change from Zinc Nacional over the past year.

Neighbor Cristóbal Palacios called on regulators to publicly share remediation details, including soil sample results and any air emissions information collected in the future.

“All of us who live near the company should be able to see the numbers with our own eyes [the government] “They say they’re going to get the amount of lead and cadmium and arsenic in the air and they should really make that transparent,” Palacios said. He and other residents said it was crucial to have enforceable deadlines for the measures.

The federal government’s actions are the latest measures to combat industrial pollution announced following the journalistic series.

The environmental regulator, known by its acronym Semarnat, said in December it was working to update three of Mexico’s industrial air pollution standards, some of which have not been revised in decades. This includes reducing the amount of particles plants are allowed to emit into the air by 50%. The president of Semarnat also told the Mexican Congress that her department was working to update Mexican standards for soil contamination.

Federal Senator Waldo Fernández, who heads the Senate committee overseeing negotiations between Mexico and the United States on North American free trade, said he is preparing a bill to amend Mexico’s environmental law to limit the importation of toxic waste and require monitoring of heavy metal emissions by factories processing materials containing heavy metals.

He said the measure, which he plans to introduce in February, would aim to stop the importation of certain types of toxic waste that are not “environmentally beneficial” for Mexico, including waste that generates heavy pollution with arsenic, lead, cadmium and other toxic elements.

And when imports do occur, “we call for stronger regulations to ensure that those imports don’t cause as much pollution,” the senator said in an interview.

Additionally, following the last article, two citizen groups took action to demand better air quality in Monterrey and better public health protection.

A group is gathering signatures for a citizens’ referendum to make airline standards similar to international guidelines. Another group, a prominent group of Monterrey activists known as the Group of 6, filed a lawsuit in December demanding a federal investigation into the industry’s air emissions in the region.

“These are environmental crimes that threaten health and life,” said Liliana Flores, one of the founders of the Group of 6.

“These are billion-dollar companies that have the resources to have clean technology. And they haven’t done it,” said Flores, who noted that thousands of people in Monterrey die each year from air pollution and many others suffer from chronic illnesses like asthma.

“It doesn’t matter if you’re rich or poor… Here, 100% of those of us who live in the metro area are affected.”