Case of Inhabitants of La Oroya v. Peru, Inter-American Court of Human Rights (27 November 2023)

The Inter-American Court of Human Rights (IACtHR) ruled in favor of 80 victims who lived in La Oroya after the installation of a metallurgical complex, determining that the State of Peru is responsible for human rights violations due to the damage caused by the activities of the La Oroya Metallurgical Complex. The ruling declared violations of the rights to a healthy environment, health, life, personal integrity, access to information and political participation, effective judicial remedies, children’s rights, and the obligation to investigate.

Proven Facts

The facts of the case relate to the La Oroya Metallurgical Complex (CMLO), operated since 1922 by various companies, including Doe Run Peru S.R.L., a subsidiary of the U.S. company The Renco Group, Inc. Para. 67. The Court highlighted that air pollution has been present since the CMLO began operations and that 99% of air pollutants in La Oroya come from this complex. Paras. 76, 67.

The Court emphasized the victims’ attempts to seek judicial protection at the national level [paras. 86-88], the precautionary measures granted by the Inter-American Commission of Human Rights (IACHR) [paras. 89-91], as well as acts of harassment and threats against some victims. Paras. 93-101.

Merits

General State Obligations

The Court reaffirmed that States have the duty to respect and guarantee human rights, which includes preventing violations by private actors [para. 109], through adequate legislation, effective oversight, and investigation of the facts. Paras. 112-113.

The Court distinguished state responsibility for acts of public companies – directly attributed to the State – and for acts of private companies, where the State has the obligation to “regulate, supervise, and monitor . . . . ” Para. 156.

Right to a Healthy Environment

In its analysis of the right to a healthy environment, the Court highlighted both procedural and substantive aspects, pointing out that “States are therefore obliged to protect nature and the environment not only because of the benefits they provide to humanity, but also because of their importance to the other living organisms with which we share the planet.” Para. 118.

Regarding air and water pollution, the Court stressed that the State is obligated to regulate quality standards, monitor air and water quality, inform the population of potential health risks, and adopt preventive measures, always in accordance with the best available science. Paras. 119-121. The Court noted the importance of the right to water as an autonomous right and its connection to the right to a healthy environment. Paras. 122-125.

The Court referred to key principles, such as the prevention of environmental damage, which must be carried out with due diligence proportional to the risk of harm. Para. 126. It also invoked the precautionary principle [para. 127] and intergenerational equity. Para. 128.

It is difficult to imagine international obligations with greater importance than those that protect the environment against unlawful or arbitrary conduct that causes serious, extensive, lasting, and irreversible environmental damage, especially in the context of the climate crisis that threatens the survival of species. In view of this, international environmental protection requires the progressive recognition of the prohibition of such conduct as a peremptory norm (jus cogens), accepted by the international community as a whole as a norm from which no derogation is permitted . . . . Para. 129.

In the specific case, the Court concluded that the metallurgical activities at CMLO were the main cause of pollution in La Oroya; that Peru was aware of this pollution, and that these activities negatively impacted the air, soil, water, and inhabitants of La Oroya. Paras. 158; 170-176; 179; 263. Despite Peru having passed environmental regulations, there was no specific regulation for environmental protection regarding mining and metallurgical activities until 1993, which violated the duty of regulation. Para. 162.

Regarding supervision and oversight, the Court found that the State delayed taking measures [para. 163] and granted exceptional extensions to the company without considering their compatibility with the objectives of environmental legislation and ignoring the pollution it was aware of, which required immediate state action. Paras. 165-168. This led to a failure to comply with “two central points pertaining to its duty of due diligence.” Para. 168. Ultimately, the Court concluded that the right to a healthy environment was violated, stating that state actions caused environmental damage, while its omissions in oversight “allowed said damage to continue after the company was privatized.” Para. 176. The Court considered that “the severity and duration of the pollution produced by the CMLO over decades suggests that La Oroya was used as a ‘sacrifice zone’  . . . . ” Para. 180.

The Court also concluded the violation of the progressive development of the right to a healthy environment due to the deliberately regressive modification of air quality standards in 2017. Paras. 187, 264.

Right to Health

The Court noted that health is “a state of complete physical, mental, and social wellbeing, and not merely the absence of diseases or infirmity” [para. 133], which is directly related to access to food and water, as well as protection from severe environmental damage.

The Court highlighted “strong evidence of the health effects of exposure to these metals” [lead, cadmium, mercury, arsenic] [para. 189]; that “mere exposure to high levels of pollutants – such as those produced by CMLO’s activities – poses a risk to human health” [para. 205], and finally that “simultaneous exposure to different polluting agents generates cumulative risks to human health.” Para. 205.

In the case under analysis, the Court referred to studies on blood metal levels in La Oroya residents. Paras. 191-196. The State argued the absence of a causal link between the victims’ diseases and exposure to pollutants in La Oroya, and the Court agreed that “in fact, there is insufficient information to establish the levels of  the aforementioned metals in the alleged victims’ blood throughout the entire period in which they were exposed to pollution, or the specific way in which said exposure caused the diseases that they acquired.” Para. 203. However, the Court noted that

in order to establish the State’s responsibility for violations of the right to health, it is sufficient to show that the State allowed levels of pollution that significantly endangered human health and that people were indeed exposed to environmental contamination in such a way that their health was imperiled. Para. 204.

Once the victims of the case were exposed to high levels of heavy metals over years and their representatives demonstrated the diseases they now suffer from as a result of such exposure [para. 206], the Court concluded that Peru violated the right to health. Para. 214. The Court also cited the precautionary principle, stating that “a lack of scientific certainty on the specific effects that environmental pollution may have on human health cannot be a justification for States to postpone or avoid the adoption of preventive measures, nor can it be invoked as justification for the failure to adopt general measures of protection for the population.” Para. 207.

Regarding healthcare, the Court observed that the State failed to provide adequate facilities to treat diseases related to pollution; that medical centers where treatment could be provided were not accessible to the victims; and that the type of treatment received was not adequate. Paras. 213, 264.

Right to Life and Personal Integrity

The Court recalled its jurisprudence on the right to life, noting that it involves positive obligations for States, such as creating a legal framework that deters threats to life, providing an effective justice system, and ensuring conditions that guarantee a dignified life, including water, food, health, and a healthy environment. Para. 136. The Court also noted that dignified life is closely linked to personal integrity. Para. 138.

In the specific case, the Court held the State responsible for violating the right to life of two victims who died from diseases due to inadequate medical attention. Paras. 215-219, 264. With regard to the disruption of the 80 victims’ lives, who lived for years without the basic conditions for a dignified life due to environmental pollution in La Oroya, the Court also found  the violation of the right to a dignified life. Para. 220-223.

The Court recalled that the victims suffered violations of their personal integrity due to intimidation and stigmatization for opposing the CMLO [para. 225], causing “psychoemotional” suffering [para. 224], and in some cases, forced them to leave La Oroya. It also considered that environmental pollution and state inaction caused suffering [para. 228] and contributed to the forced migration of some victims. Para. 230. The Court also stressed that the impacts of pollution disproportionately “affect individuals, groups and communities that already bear the burden of poverty, discrimination and systemic marginalization.” Para. 231.

Children’s Rights

The Court highlighted the special protection that children are entitled to against environmental pollution and the emission of pollutants that contribute to climate change [paras. 141 and 143], requiring greater diligence and state oversight when their rights are at risk. Para. 142.

The Court noted that the evidence presented “establish that a child’s health and development may be particularly affected by exposure to heavy metals, especially lead” [para. 236], which requires special protective measures against the differentiated impacts. Para. 242. It is relevant that the Court considered that since 1981, when it could exercise its contentious jurisdiction regarding Peru, 57 of the victims were or are children. Para. 238. Furthermore, the State’s failure to oversee and control activities at CMLO constituted a violation of the special protection duty concerning children’s rights in relation to those victims. Paras. 242, 264.

Right to Access Information

The Court emphasized that access to information about activities with potential environmental impact is of clear public interest and highlighted the State’s duty for active transparency. Paras. 145-147. 

In the specific case, it was acknowledged that the State took measures to inform the population about the pollution [paras. 248–252], but that these were “insufficient to ensure effective access to information” [para. 255] and, therefore, violated the right to information, since adequate elements were not provided to make the risks to health, personal integrity, and life known. Para. 265.

Right to Political Participation

With regard to political participation, the Court noted the State’s obligation to guarantee the participation of individuals under its jurisdiction “in decision-making and policies that may affect the environment […].” Para. 152.

Although the Court acknowledged that the State had taken some measures to enable citizen participation in environmental matters [paras. 257–260, 265], it considered that it was not possible to determine whether these measures provided the victims with effective opportunities “to be heard and to participate in decision-making […].” Para. 260. Therefore, it concluded that the State had violated the right to political participation.

Right to Judicial Protection and Duty to Investigate

The Court emphasized that States have an obligation to guarantee access to justice, including the right to effective remedies, due process, and reparation for any violation of human rights. Para. 273. Furthermore, the Court reinforced that “the effectiveness of the judgments depends on their execution”, which must be “complete, perfect, comprehensive and timely”. Para. 274. In this case, the Court found that the State failed to comply with some orders issued by the Constitutional Court [para. 283] and that the measures taken were ineffective or delayed. Para. 290, 297. This led to a violation of the duty to guarantee judicial protection.

Regarding the lack of investigation, the Court underlined the particular importance of conducting investigations in contexts where there are threats against human rights defenders, including environmental defenders. Paras. 303, 305. In the case of La Oroya, the acts of harassment against some victims occurred in a context of social conflict, where their opposition to environmental pollution was perceived by some CMLO workers as a threat to their livelihood. Para. 307. The Court described the victims’ mobilization and denunciation efforts, as well as the harassment they suffered. Para. 311-316. Ultimately, the Court concluded that the State failed to conduct a diligent investigation into the reported facts. Para. 319.

Conclusions and Reparations

For all of these reasons, the Court declared Peru responsible for the violation of the rights to a healthy environment, health, life, dignified life, personal integrity, access to information and political participation, effective judicial remedy, judicial guarantees, judicial protection (duty to investigate), as well as the rights of children (Articles 26, 4.1, 5, 19, 13, 23, 25.2.c, 8.1, 1.1, and 2 of the American Convention).

Finally, the Court ordered the State to promote investigations regarding the acts of threats and harassment against the victims of the case and the environmental contamination in La Oroya [para. 142, point 12]; to carry out a baseline diagnosis and an action plan to remediate the environmental damages. Para. 142, point 13. The State was also ordered to provide “free and for as long as necessary” medical, psychological, and psychiatric treatment to the victims [para. 142, point 14], and to establish a system of specialized medical care. Para. 142, point 18. Beyond monetary compensation for material and immaterial damages [para. 142, point 23], the Court also ordered measures of satisfaction, such as a public act recognizing international responsibility [para. 142, point 15], and measures of non-repetition, such as harmonizing legislation defining air quality standards, ensuring the effectiveness of the alert system, and training judicial and administrative officials. Para. 142, points 16, 17, and 20.

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