By David Boyd, UN Special Rapporteur on Human Rights and the Environment.

“Environmental degradation can cause irreparable damage to human beings, which is why a healthy environment is a fundamental right for the existence of humanity.” – Inter-American Court of Human Rights, 2024

The Inter-American Court of Human Rights handed down a landmark decision on Friday, March 22, in a case involving allegations that more than a century of catastrophic industrial pollution from La Oroya Metallurgical Complex in Peru violated the right to a healthy environment. 

Generations of people in the community were poisoned by lead, arsenic and other toxic substances, resulting in a devastating array of physical and mental illnesses and in some cases, death. The Court concluded there were extensive human rights violations and ordered the State to provide specialized medical assistance to the victims, pay compensation for both material losses and pain and suffering, and publicly acknowledge its wrongdoing. 

Each identified victim will receive between US$30,000 and US$65,000, with larger sums going to children, women and older persons due to their particular vulnerabilities. This includes compensation for health costs and lost earnings as well as compensation for pain and suffering. While no amount of money can fully compensate a person for damage to their health or their developmental potential, these damage awards should improve the victims’ quality of life.

More broadly, Peru was ordered to strengthen and strictly enforce environmental standards, rehabilitate damaged ecosystems, monitor air, water and soil quality, ensure that polluters pay for the environmental damage they cause. Finally, the State was ordered to investigate and prosecute those responsible for the extensive environmental damage, as well as those responsible for threats against environmental human rights defenders in La Oroya.

Facing for the first time a contentious case involving toxic pollution, the Inter-American Court built upon its widely cited Advisory Opinion on human rights and the environment from 2017. The Court clarified that the right to a healthy environment is comprised of a bundle of procedural and substantive elements (para. 118). 

The procedural elements include access to information, public participation in decision-making, and access to justice with effective remedies. The substantive elements include clean air, safe and sufficient water, healthy and sustainably produced food, non-toxic environments where people can safely live, work, learn and play, healthy ecosystems and biodiversity, and a safe, livable climate. 

The case was originally brought to court in 2002, reaching Peru’s Constitutional Court in 2006. While that court also found violations of the rights to a healthy environment and health, its orders were never fully implemented by the government of Peru. A petition was filed with the Inter-American Commission on Human Rights in 2005, resulting in precautionary measures that Peru also never fully implemented. 

In 2021, the Commission sent the case to the Inter-American Court. There were 80 named victims, but the Court also recognized the collective nature of the right to a healthy environment in reaching its decision and crafting its extensive orders. Obviously, the extensive pollution, covering more than 2,300 square kilometers, harmed more than just 80 people.

The level of contamination in La Oroya was so severe that the Court agreed with the Special Rapporteur’s earlier identification of the community as a sacrifice zone (A/HRC/49/53), an area where environmental contamination caused by the reckless pursuit of profit is so egregious that it constitutes a systematic violation of the human rights of its residents (para 180).

Citing the work of the Special Rapporteur, the Court noted “that the effects derived from environmental pollution fall disproportionately on people, groups and communities that already bear the weight of poverty, discrimination and systemic marginalization. Thus, the risk of harm is particularly high for those segments of the population that are currently in a situation of marginalization or vulnerability, including pregnant women, children, adolescents, and older people” (para 231).

The Court referred to the recent General Comment 26 of the Committee on the Rights of the Child as support for its conclusion that “when the type of pollution produced by company operations constitutes a high risk for the rights of children, States must require a stricter due diligence process and an effective surveillance system” (para 142).

The Court concluded that the State’s failure to prevent extensive and enduring air, water and soil pollution violated the rights to a healthy environment, health, life, physical and mental integrity, dignity, and the rights of the child. Peru also violated the right of access to information by failing to provide accessible and understandable information about the environmental contamination and associated health risks. The State violated the right to public participation by failing to provide opportunities for the victims to engage in decision-making relating to the operation and environmental impacts of the La Oroya metallurgical complex.

In echoing the UN Special Rapporteur on human rights and the environment (A/HRC/40/55), the Court confirmed that “people enjoy the right to breathe clean air as a substantive component of the right to a healthy environment, and, therefore, the State is obliged to: a) establish laws, regulations and policies that ensure air quality standards do not constitute risks to health; b) monitor air quality and inform the population of possible health risks; c) carry out action plans to control air quality that include the identification of the main sources of air pollution, and implement measures to enforce air quality standards (para. 120). 

Similar observations were made regarding clean water as a substantive element of the right to a healthy environment. In the words of the Court: 

This substantive element of the right to a healthy environment imposes the obligation on States to: a) design norms and policies that define water and wastewater quality standards that are compatible with human and ecosystem health; b) monitor the levels of contamination of water bodies and, if applicable, report possible risks to human and ecosystem health; c) make plans and policies with the purpose of controlling water quality that include the identification of main causes of contamination; d) implement measures to enforce water quality standards, and e) adopt actions that ensure the management of water resources in a sustainable manner (para. 121).

The metallurgical complex had been operated by a combination of public and private businesses. The Court reiterated that the obligations of the State regarding human rights violations caused by all business enterprises are to “prevent, investigate, punish and redress such abuses through appropriate policies, regulatory activities and prosecution” (para. 110). 

The Court determined, on the basis of extensive evidence that even the weak Peruvian environmental standards were being violated and that no adequate remedial measures were taken. Therefore, Peru had failed to fulfil its obligations related to regulating, supervising, inspecting, monitoring and enforcing rules against business enterprises. This constituted a violation of the right to a healthy environment (para. 176).

An important aspect of the Court’s decision is its emphasis on the principles of prevention and precaution. Pursuant to the principle of prevention, “States are obliged to use all means at their disposal in order to prevent activities carried out under their jurisdiction from causing significant damage to the environment. This obligation must be fulfilled under a standard of due diligence, which must be appropriate and proportional to the degree of risk of environmental damage” (para 126). 

In cases such as La Oroya, where the high toxicity of substances including lead and arsenic was well established, the due diligence obligation has a higher standard. In developing and implementing all environmental laws and policies, the State must be guided by the best available science.

Regarding the precautionary principle, the Court noted that while it is scientifically difficult to establish cause and effect between any individual’s exposure to toxic substances and subsequent health impacts, the science regarding elevated risks related to known exposures is sufficient for imposing upon States the obligation to take effective measures to prevent serious or irreversible damage. 

According to the Court, “it is sufficient to establish that the State allowed the existence of levels of contamination that put people’s health at significant risk and that people were actually exposed to the environmental contamination in such a way that their health was at risk” (para. 204).

A key element of the case is the Court’s articulation of the principle of non-regression. In 2017, Peru severely weakened its air quality standards for sulfur dioxide. The Court explained that this regression in environmental standards was incompatible with the fundamental principle of progressive realization of economic, social, cultural and environmental rights (noting that there are also some obligations of immediate enforceability). The weakening of the standard was deliberate, unjustified, and breached the State’s obligation to progressively develop the right to a healthy environment (paras 186-187).

Intergenerational equity is another principle emphasized by the Court in the context of the right to a healthy environment because “guaranteeing the interest of both present and future generations and the conservation of the environment against its radical degradation is essential for the survival of humanity” (para 129).

Finally, the Court highlighted the importance of environmental human rights defenders, noted the threats and harassment suffered by many of the victims, and criticized Peru’s abject failure to seriously and effectively investigate the violations committed against them (paras. 318-19).

The Inter-American Court’s decision is the strongest and most comprehensive judgment of any regional human rights court to date. Not only does it provide long overdue environmental justice for the people of La Oroya in Peru, it also establishes a vital precedent that will be used by concerned citizens, communities, courts, and environmental human rights defenders all over the world. 

In the context of a planetary environmental crisis, the Inter-American Court has demonstrated exemplary vision, courage, and leadership. It is time for governments and business enterprises to do the same.