Restore Health in Cerro de Pasco

Cerro de Pasco, located 4,500 meters above sea level in the Peruvian Andes, is one of the most polluted cities in the world. Air, soil, wildlife, livestock, water and, consequently, human health, are all severely affected by high concentrations of heavy metals, due to tha mining activity. Since the 20th century, the huge open-pit mine has been expanding in the center of the city, reshaping both the urban and natural landscapes, displacing neighborhoods, draining lakes, and exposing the environment and at least 70.000 residents to pollution.

The Quiulacocha and Yanamate lagoons are emblematic of these impacts: originally natural lakes (“Quiulacocha” is named after the Andean gulls that once could be found on its shores), since the 1980s, they have served as discharge sites for untreated acidic mine drainage, leading to the complete disruption of their ecosystems. Now these lagoons have a highly acidic pH and extreme concentrations of dissolved metals – often thousands of times higher than national and international regulatory standards. 

Since 2008, Source International has been working in Cerro de Pasco to document and prove, with data in hand, the widespread environmental contamination caused by the city’s open-pit mine and its related activities.

 In collaboration with Labor, a local NGO, Source International carried out a new independent monitoring campaign in July 2024. Clara and Flaviano took and analyzed 9 surface water samples and 2 tap water samples from Cerro de Pasco and surrounding areas. These data add to the growing body of evidence of water contamination from the local mining industry, reinforcing findings from previous campaigns conducted in 2008, 2016, 2019, 2022, and 2023 (1). 

This report will be available soon, but here’s a preview...

Results confirm a worrying but sadly familiar picture: surface waters remain highly contaminated with heavy metals, with 32 exceedances of the Peruvian environmental quality standards for the protection of aquatic and agricultural ecosystems. 

The most critical situations were found again in the Quiulacocha and Yanamate lagoons, where elements such as cadmium, lead, copper, zinc, and manganese exceeded legal limits by up to several thousand times. Other water bodies – such as the San Juan and Tingo rivers – also showed elevated levels, although generally lower than in the lagoons, and with slight improvements compared to 2022 for some parameters. The pollution of lagoons and rivers inevitably translates into contamination of soils, livestock, and agricultural production. 

On a more positive note, drinking water samples were mostly compliant with national health standards, except for a slightly high value of iron, a parameter describing water’s organoleptic quality rather than safeness for human consumption.

Despite some encouraging signs, these findings add to the growing body of evidence demonstrating the high potential for chronic heavy metal exposure in the population of Cerro de Pasco. The persistence of heavy metals such as cadmium and lead – both classified by WHO among the major public health threats – shows that the environmental and humanitarian crisis in Cerro de Pasco is far from resolved. 

Chronic exposure continues to pose serious risks to local populations, especially children: clinical and biomonitoring studies indicated that virtually all children in Cerro de Pasco carry detectable levels of heavy metals in their blood, urine, and hair, often exceeding international reference thresholds. Lead, arsenic, and mercury are the most prevalent, and their presence is closely linked to the significantly lower QI scores among Pasco’s children as compared to nearby control communities. Despite the National Ministry of Health declaring a sanitary emergency and being informed of the situation, children in Cerro de Pasco continue to suffer – and even die – from chronic exposure to these toxic metals, with the most recent reported fatality occurring in early 2025 (2). 

This new report therefore provides an updated and solid basis for legal and advocacy actions, and reinforces the urgent need for effective and lasting remediation and environmental protection measures.

The full technical report will be published online in the coming months. Stay tuned!

Links:

• (1) Source International - website - Cerro de Pasco
• (2) Environmental News. Death reported of 12-year-old girl

March and April were important months for the members of Source International and Red Interquorum Pasco.

Albert (21) and Mireya (22), two young activists from Red Interquorum Pasco—a student organisation committed to justice and human rights in Cerro de Pasco—undertook an impactful journey to Italy. Thanks to the support of Source International, they received the Operation Daywork Human Rights Award, which gave them the opportunity to travel to Italy and share their story.

Albert and Mireya arrived in Bolzano in early March and spent three weeks engaging with Italian high school students through awareness-raising workshops in more than 20 classrooms. In each session, they shared personal testimonies about the ongoing environmental and human rights violations suffered by the people of Cerro de Pasco as a result of decades of mining.

After this first phase, the Pasco Tour in Italy began—an awareness campaign that brought Mireya and Albert, along with Clara and Flaviano from Source International, to cities across the country: Trento, Milan, Genoa, Rome, Naples, and Florence.

During these events, Mireya and Albert gave powerful testimonies: how they became aware of the destruction caused by mining, and how—through their work with Red Interquorum Pasco—they are organising their community, educating their peers, and resisting normalized violence. 

Source International complemented their voices with insights drawn from over ten years of scientific research and advocacy in the region. We presented the results of our environmental health studies, our legal fights, and the small but meaningful victories achieved together with local communities over the years.

Throughout the tour, we built strong connections with both young people and adults in Italy, and we expanded our international network of solidarity and support. 

What is the objective of all this?

To make the case of Cerro de Pasco as widely known as possible. We want to amplify the voices of those living through this crisis and bring their stories into public discourse and institutional spaces. The more people become aware, the stronger the pressure for accountability. The greater the international resonance, the closer we move toward justice.

We want environmental crimes - like the one unfolding in Cerro de Pasco - to be recognized and prosecuted under international law.

That is why we are heading to... Geneva!

Together with several partners—including the University of Oxford, Joint Research Centre of the European Commission (JRC), TRIAL International, Physicians for Human Rights, and Justice Rapid Response—we are organizing a high-level expert consultation to kickstart the development of practitioner-oriented guidelines for documenting and investigating international environmental crimes.

This initiative responds to the urgent need for stronger international mechanisms to address environmental harm as a criminal offense. The consultation will bring together legal experts, scientists, civil society leaders, and academics from across the globe to: identify key challenges in documenting and prosecuting environmental crimes; share lessons learned and best practices; promote multidisciplinary collaboration; develop robust and reliable standards for investigation and litigation.

We are proud to announce that Mireya will join us in Geneva to represent the voices of those directly affected by environmental crimes. Her testimony will be a vital contribution to the conversation—offering not just data and facts, but lived experience, resilience, and the urgent demand for justice. 

Links:

• Source International website