Environmental Contamination in Cerro De Pasco

Case Status: Ongoing

Location: City of Cerro de Pasco, Pasco Province, Peru

CASE SUMMARY

On May 28, 2026, the mayor of the provincial municipality of Pasco, with legal advice and support from EarthRights International, filed a constitutional protection lawsuit (amparo) with the Peruvian Constitutional Court against the Volcan mining group. The purpose of the lawsuit is to hold the companies accountable for the damage they have caused in the city of Cerro de Pasco over the course of nearly three decades.

This legal action aims to have the Judiciary recognize the human rights abuses committed by these companies due to the severe heavy metal contamination they have caused in the environment. This contamination affects water, soil, and air. These effects impact health, personal integrity, access to adequate food, and the lives of the city’s residents, particularly children.

BACKGROUND

Cerro de Pasco, a historically mining city, is considered by experts to be one of the most polluted places in the world. An open-pit mine, approximately 2 km long, 1.8 km wide, and 800 meters deep, sits in the center of the city. Tons of ore rock have been extracted from the mine for decades. Mining extraction has caused a serious accumulation of heavy metals. So have processing plants and designated waste storage areas. This accumulation threatens the health of its inhabitants. 

From 2008 to 2023, companies in the Volcan group received 50 sanctions, primarily for environmental violations, according to reports from the Environmental Evaluation and Enforcement Agency and the National Water Authority. These violations include exceeding legally permitted limits of heavy metals, discharging mining waste into water sources, failing to conduct environmental impact assessments (EIAs), and lacking corrective plans. 

Mining operations severely affect the rivers, lagoons, and local communities across the districts of Simón Bolívar, Yanacancha, and Chaupimarca.

Scientific reports by Source International from 2009 to 2023 reveal that levels of heavy metals in rivers, lagoons, recreational parks, schoolyards, pastures, and agricultural soils exceed national regulations and international standards. 

Contamination of Water Sources

The Quiulacocha and Yanamate lagoons, natural water sources, have been turned into tailings ponds for toxic mining waste. According to a 2019 analysis, the manganese level in Quiulacocha lagoon exceeds the limit established by Peru’s Environmental Quality Standards (ECA) by 46,666 times. 

The situation at the headwaters of the Tingo River is also notable for its severity. Over time, tons of waste rock from the mining process have been deposited there, forming the Rumiallana waste dump. This has caused severe contamination of the river from its source.

Health Impacts

Scientific research has also revealed that a significant part of the population of Cerro de Pasco has high concentrations of heavy metals — such as lead, arsenic, mercury, cadmium, chromium, copper, zinc, antimony, molybdenum, manganese, iron, tin, nickel, thallium, vanadium, aluminum, barium, and cobalt — in their bodies. 

The World Health Organization (WHO) has stated that there is no safe level of lead exposure for humans, its high toxicity seriously threatens health and the environment. Exposure to lead and other heavy metals can cause irreversible damage and chronic illnesses, such as cancer, anemia, hypertension, kidney failure, pulmonary conditions, and infertility, among others. Furthermore, it poses an especially severe risk to children, affecting their cognitive development.

Organizations and media outlets in Peru have documented severe health impacts on residents, particularly minors, including fatalities due to heavy metal poisoning. 

Despite these facts, the company continues to deny responsibility and, moreover, has taken no steps to correct its behavior.  

Given this situation, the Mayor of the Provincial Municipality of Pasco filed a lawsuit seeking to have the Judiciary order the Volcan group companies to repair environmental and health damages caused to the city and its population, as well as to implement non-repetition measures to effectively guarantee that such damages will not occur again.