Project
Protecting the health of La Oroya's residents from toxic pollution
For more than 20 years, residents of La Oroya have been seeking justice and reparations after a metallurgical complex caused heavy metal pollution in their community—in violation of their fundamental rights—and the government failed to take adequate measures to protect them.
On March 22, 2024, the Inter-American Court of Human Rights issued its judgment in the case. It found Peru responsible and ordered it to adopt comprehensive reparation measures. This decision is a historic opportunity to restore the rights of the victims, as well as an important precedent for the protection of the right to a healthy environment in Latin America and for adequate state oversight of corporate activities.
Background
La Oroya is a small city in Peru’s central mountain range, in the department of Junín, about 176 km from Lima. It has a population of around 30,000 inhabitants.
There, in 1922, the U.S. company Cerro de Pasco Cooper Corporation installed the La Oroya Metallurgical Complex to process ore concentrates with high levels of lead, copper, zinc, silver and gold, as well as other contaminants such as sulfur, cadmium and arsenic.
The complex was nationalized in 1974 and operated by the State until 1997, when it was acquired by the US Doe Run Company through its subsidiary Doe Run Peru. In 2009, due to the company's financial crisis, the complex's operations were suspended.
Decades of damage to public health
The Peruvian State - due to the lack of adequate control systems, constant supervision, imposition of sanctions and adoption of immediate actions - has allowed the metallurgical complex to generate very high levels of contamination for decades that have seriously affected the health of residents of La Oroya for generations.
Those living in La Oroya have a higher risk or propensity to develop cancer due to historical exposure to heavy metals. While the health effects of toxic contamination are not immediately noticeable, they may be irreversible or become evident over the long term, affecting the population at various levels. Moreover, the impacts have been differentiated —and even more severe— among children, women and the elderly.
Most of the affected people presented lead levels higher than those recommended by the World Health Organization and, in some cases, higher levels of arsenic and cadmium; in addition to stress, anxiety, skin disorders, gastric problems, chronic headaches and respiratory or cardiac problems, among others.
The search for justice
Over time, several actions were brought at the national and international levels to obtain oversight of the metallurgical complex and its impacts, as well as to obtain redress for the violation of the rights of affected people.
AIDA became involved with La Oroya in 1997 and, since then, we’ve employed various strategies to protect public health, the environment and the rights of its inhabitants.
In 2002, our publication La Oroya Cannot Wait helped to make La Oroya's situation visible internationally and demand remedial measures.
That same year, a group of residents of La Oroya filed an enforcement action against the Ministry of Health and the General Directorate of Environmental Health to protect their rights and those of the rest of the population.
In 2006, they obtained a partially favorable decision from the Constitutional Court that ordered protective measures. However, after more than 14 years, no measures were taken to implement the ruling and the highest court did not take action to enforce it.
Given the lack of effective responses at the national level, AIDA —together with an international coalition of organizations— took the case to the Inter-American Commission on Human Rights (IACHR) and in November 2005 requested measures to protect the right to life, personal integrity and health of the people affected. In 2006, we filed a complaint with the IACHR against the Peruvian State for the violation of the human rights of La Oroya residents.
In 2007, in response to the petition, the IACHR granted protection measures to 65 people from La Oroya and in 2016 extended them to another 15.
Current Situation
To date, the protection measures granted by the IACHR are still in effect. Although the State has issued some decisions to somewhat control the company and the levels of contamination in the area, these have not been effective in protecting the rights of the population or in urgently implementing the necessary actions in La Oroya.
Although the levels of lead and other heavy metals in the blood have decreased since the suspension of operations at the complex, this does not imply that the effects of the contamination have disappeared because the metals remain in other parts of the body and their impacts can appear over the years. The State has not carried out a comprehensive diagnosis and follow-up of the people who were highly exposed to heavy metals at La Oroya. There is also a lack of an epidemiological and blood study on children to show the current state of contamination of the population and its comparison with the studies carried out between 1999 and 2005.
The case before the Inter-American Court
As for the international complaint, in October 2021 —15 years after the process began— the IACHR adopted a decision on the merits of the case and submitted it to the Inter-American Court of Human Rights, after establishing the international responsibility of the Peruvian State in the violation of human rights of residents of La Oroya.
The Court heard the case at a public hearing in October 2022. More than a year later, on March 22, 2024, the international court issued its judgment. In its ruling, the first of its kind, it held Peru responsible for violating the rights of the residents of La Oroya and ordered the government to adopt comprehensive reparation measures, including environmental remediation, reduction and mitigation of polluting emissions, air quality monitoring, free and specialized medical care, compensation, and a resettlement plan for the affected people.
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Victims in La Oroya call on the President of Peru to comply with the Inter-American Court ruling after nearly two years of delays
The group of victims recognized by the international court emphasizes the urgency of implementing the ruling on issues related to ending pollution in the city of La Oroya, providing comprehensive and specialized medical care, and paying compensation. La Oroya, Peru. Victims of decades of pollution caused by the operations of the La Oroya Metallurgical Complex sent a letter to the President of the Republic on December 19, 2025, urgently requesting compliance with the Inter-American Court of Human Rights' ruling ordering the Peruvian State to adopt comprehensive measures of justice and reparation. In the letter, part of the group of 80 victims recognized by the international court in the La Oroya v. Peru case, the group emphasizes compliance with the ruling on issues related to pollution prevention in the city, comprehensive and differentiated medical care, and the payment of compensation."Mr. President, do we have to wait another 20 years to obtain some kind of reparation? Since we began this long struggle, seven people from this group of victims have died without obtaining justice. Two of them, including a minor, died as a result of health damage caused by pollution in La Oroya, as the Inter-American Court of Human Rights confirmed in its ruling," the victims point out.Their request comes after almost two years of delays in the effective implementation of the ruling, notified on March 22, 2024, and after the Inter-American Court of Human Rights notified its interpretative judgment in November last year, in which it referred only to certain specific aspects of the original judgment that required further clarification to facilitate its execution. These points relate to health care measures, the relocation of affected persons, follow-up deadlines, compensation, and the acknowledgment of responsibility and a public apology.However, both the victims and the organizations supporting their struggle emphasize that, as established by the Inter-American Court, all orders in the original judgment are in force and fully enforceable from the moment they were issued in March 2024, with no legal impediment to immediate compliance.An essential step in achieving this is the urgent publication of the resolution determining jurisdiction by the Attorney General's Office."The victims have resorted to all legal and institutional mechanisms to access justice and see their rights restored. Today, preventing the population of La Oroya from continuing to be exposed to environmental pollution, guaranteeing comprehensive health care for those who have been affected by toxic metals, and ensuring the payment of compensation ordered by the Court are necessary and fully implementable steps for the Peruvian State to comply not only with its international obligations, but also with its fundamental duty to protect the life, health, and dignity of the people who inhabit its territory," said Rosa Peña, senior attorney at the Interamerican Association for Environmental Defense (AIDA). Christian Huaylinos, from the legal department of the Pro Human Rights Association (APRODEH), highlighted the importance of implementing the ruling throughout the country: "Several of the provisions ordered by the Court are relevant at the national level, meaning that they benefit Peruvian citizens in general in relation to pollution from mining and metallurgical activities. These include harmonizing national-level air quality regulations, guaranteeing respect for human rights and due diligence, and designing and implementing an air and water quality information system in areas of Peru with greater mining and metallurgical activity. In this regard, achieving timely and efficient compliance by the State represents the significance of the case for the benefit of all Peruvians."The victims emphasize that, given the clarifications made by the Inter-American Court in its interpretative judgment, there is no justification for the institutional delays that for more than two decades have prevented access to justice and reparation for the families affected by the pollution generated by the La Oroya Metallurgical Complex.This case has become one of the most important precedents in Latin America for protecting the rights to a healthy environment, clean air, and health, especially for communities exposed to highly polluting business operations. After more than 20 years of struggle, the victims hope that the Peruvian State will finally guarantee the justice and reparation ordered by the Inter-American Human Rights System. The victims, the population of La Oroya, and the organizations involved in the case reiterate their willingness to collaborate with the responsible institutions to ensure the effective implementation of all measures and to move toward comprehensive reparation and non-repetition.Press contactVíctor Quintanilla (Mexico), AIDA, [email protected], +521 5570522107
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Science in the Service of Environmental Justice
By David Cañas and Mayela Sánchez* Science—or rather, the sciences—are the systems of knowledge that different social groups have developed over time to describe the phenomena of nature and society. Thanks to these knowledge systems, humanity has been able to find solutions to countless challenges, and today, more than ever, they must respond to global crises such as climate change, pollution, and biodiversity loss.Understanding ecosystem processes is essential for protecting the environment and providing verifiable, replicable evidence of natural phenomena and the impacts of human activities. It also enables the development of innovative solutions to protect and restore the environment.For science to contribute meaningfully to environmental justice—a concept centered on ensuring that all people enjoy a healthy environment—scientific work must be grounded in the realities of the people and communities affected by environmental degradation, who live in or rely on ecosystems vulnerable to harm. It must also be built on empathy and respect for other forms of knowledge, while seeking to reduce social inequalities.At AIDA, science is a central part of our work, supporting and complementing the strategic litigation we pursue to protect a healthy environment in Latin America. Through science, we can demonstrate the environmental impacts caused by human activities and hold those responsible accountable. How Do We Do Science at AIDA? The AIDA scientific team is a multidisciplinary group of professionals specializing in diverse fields, including geography, geology, biology, marine biology, oceanography, anthropology, and economics.Among other tasks, they collect and develop scientific evidence to strengthen the legal arguments in the cases we support across our various lines of work—from protecting the ocean and other critical ecosystems to defending human rights, such as the right to health and access to safe drinking water.The strategic use of science has been central to AIDA’s work since the organization was founded more than 25 years ago. One early example is the case of La Oroya in Peru, where a group of residents sued the government for failing to protect them from decades of heavy metal pollution caused by a metallurgical complex.Then we did something that had not been done before: we connected existing studies with the lived reality of La Oroya. This approach allowed us to demonstrate the relevance of the case and establish a clear link between pollution and its impact on the health of the city’s residents. Our analysis, compiled in the report La Oroya Cannot Wait, served to build the legal case and formulate proposals to the Peruvian government for corrective and preventive measures to address the problem. In 2024, in a decision that set a historic precedent for state oversight of industrial pollution, the Inter-American Court of Human Rights held the Peruvian state responsible and ordered it to adopt comprehensive reparations measures. Among the scientific team’s more recent contributions is a geospatial analysis of the Salar del Hombre Muerto in the Argentine provinces of Catamarca and Salta. Using maps and satellite imagery, the team documented water loss in this ecosystem caused by lithium mining.Another example is the expert report on solid waste pollution in the tributaries of the Motagua River in Guatemala, in which we recorded and characterized illegal dumps along the banks of the Chinautla River. This work enabled the affected communities to gather the evidence needed for the lawsuit they filed against the municipality of Chinautla for failing to address the contamination of rivers and soil caused by inadequate solid waste management. The Right to Science When science serves social and environmental justice, its benefits extend to everyone. This purpose was recently upheld by the Inter-American Court of Human Rights in its Advisory Opinion 32, which recognizes the “right to science” as the right of all people to enjoy the benefits of scientific and technological progress, as well as to have opportunities to contribute to scientific activity without discrimination.The Court also recognized indigenous, traditional, and local knowledge as equally valid forms of knowledge. This acknowledges how the deep understanding that indigenous peoples and local communities have of their environment—their worldview based on respect and interdependence, and their spiritual connection to nature—has been fundamental to ecosystem conservation.As an organization that uses science as a tool for environmental protection, we believe in a science that embodies these principles: one built on dialogue between different forms of knowledge, whose benefits reach all people, and which contributes to the socio-ecological transformation the planet urgently needs. *David Cañas is AIDA's Interim Director of Science; Mayela Sánchez is our digital community specialist.
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Families of La Oroya demand Peru comply with Inter-American Court ruling
One year after the decision, the state has still not implemented the ordered reparations. The population lacks comprehensive health care and is once again exposed to toxic contamination due to the reactivation of the La Oroya smelter complex, which is operating without adequate environmental management.One year after the Inter-American Court of Human Rights ordered the Peruvian state to provide comprehensive reparations to the residents of La Oroya, after finding it responsible for violating their rights, the victims are still waiting for the ruling to be implemented and for state to comply with its international obligations."It's already been a year since the ruling was announced, how much longer will we have to wait?" asked Yolanda Zurita, a resident of La Oroya and a petitioner in the case. "Enough is enough! We demand that the Peruvian state immediately comply with the ruling of the Inter-American Court, which will benefit not only the victims of the case, but also the population of La Oroya and the country exposed to toxic substances from the indiscriminate development of extractive and industrial activities in our territories."On March 22, 2024, in a landmark decision for the protection of a healthy environment in Latin America, the Court responded to the long and tireless search for justice by the families of La Oroya, who have been affected for decades by the extreme levels of contamination from the La Oroya Metallurgical Complex (CMLO) and the lack of adequate protective measures by the State, which today ignores the ruling and underestimates its importance.Although the Court ordered the State to ensure that CMLO's operations comply with international environmental standards and to prevent and mitigate damage to the environment and human health, the opposite is currently the case: the complex has reactivated its operations without having modernized its facilities to prevent and mitigate the environmental and health risks it generates for the population.It is urgent that the CMLO stops polluting and that the Peruvian State adopts the measures required by the Court to modernize it in accordance with international environmental standards of environmental protection, in compliance with the ruling."With the reactivation of the metallurgical complex, the people of La Oroya are once again being exposed to levels of pollution that endanger their lives; the Inter-American Court's ruling is clear and the State is obligated to comply," said Rosa Peña, senior attorney with the Inter-American Association for Environmental Defense (AIDA). "The delay in complying with the ruling is re-victimizing the families who have been demanding justice for more than 20 years."The court also ordered the state to provide free medical care to the victims and to guarantee specialized care to residents with symptoms and illnesses related to contamination from the mining and metallurgical activities. Today, however, comprehensive health care is not guaranteed in La Oroya. It is necessary that the State, through and in coordination with the Ministry of Health, the Regional Health Directorate of Junín, the General Directorate of Environmental Health, and health care providers, create and implement the protocol for comprehensive care for victims in La Oroya, as established by the Court.The ruling set a historic precedent for the control of industrial pollution by states. For the Peruvian State to make real progress in its implementation, it is imperative that the Attorney General's Office issue the Compliance Resolution."Despite the deadlines set by the Inter-American Court for the Peruvian State, there has been virtually no progress in the implementation of the ruling," said Christian Huaylinos, coordinator of the legal department of the Pro Human Rights Association (APRODEH). "Above all, the nature of the case must be taken into account, which implies that La Oroya has been classified as a sacrifice zone due to the high levels of contamination; therefore, the need to fully compensate the victims is urgent." Background of the caseLa Oroya is located in the central mountain range of Peru, in the department of Junin, 176 km from Lima. In 1992, the US company Cerro de Pasco Corporation installed the La Oroya Metallurgical Complex (CMLO) to process mineral concentrates. The complex was nationalized in 1974 and operated by the state under the name Centromin Peru until 1997, when it was taken over by Doe Run Peru, which operated it until 2009. In short, the CMLO is over 100 years old.In La Oroya, most of the people affected by the CMLO contamination, including children, have lead levels higher than those recommended by the World Health Organization. In some cases, they have registered higher levels of arsenic and cadmium, in addition to stress, anxiety, skin problems, stomach problems, chronic headaches, and respiratory or cardiac problems, among others.In the absence of effective responses at the national level and on behalf of the victims, an international coalition of organizations filed a complaint against the Peruvian State with the Inter-American Commission on Human Rights in 2006. In October 2021, the Commission found the Peruvian government responsible and referred the case to the Inter-American Court. In October 2022, more than 16 years after the international complaint was filed, the victims, represented by AIDA and APRODEH with the assistance of Earthjustice, brought the case before the Court. Press contactsVíctor Quintanilla (Mexico), AIDA, [email protected], +52 5570522107María Nieve Sullón (Peru), APRODEH, [email protected], +51 984926868
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