On November 27, 2023, the Inter-American Court of Human Rights (IACtHR) delivered its judgment in La Oroya v. Peru, its first caseFootnote ¹ involving pollution affecting a city’s inhabitants. The judgment is significant for: (1) the detailed development of the contents and nature of the right to a healthy environment (RHE), including its potential status as a jus cogens norm, in the context of serious and protracted urban pollution; and (2) the diverse reparation measures ordered to redress the harm inflicted on victims and the environment. In the judgment, the IACtHR found Peru responsible for violating the American Convention on Human Rights (ACHR)Footnote ² and ordered reparations against Peru in favor of the City of La Oroya’s inhabitants for the violations of the RHE and other rights.

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For several decades, starting in 1922, La Oroya’s environment and the health of its inhabitants were severely affected by serious harm as a consequence of the pollution related to mining/metallurgic activities in the La Oroya Metallurgical Complex owned/managed by international private companies during most of its existence (paras. 67–84). The levels of toxic pollutants largely exceeded environmental air quality standards, which correlated with acute respiratory infections, especially affecting children (para. 78). Lead, cadmium, and arsenic emissions also affected the soil (para. 84). In La Oroya, there were eighty victims, comprising seventeen families and six persons, including six fatalities (para. 85). Peru adopted measures to improve environmental conditions and address health issues only in the late 2000s, following Peruvian Constitutional Tribunal’s and Inter-American Commission of Human Rights’ decisions (para. 92); however, to a greater or lesser extent, these measures were insufficient. The judgment is divided into two main sections—the first regarding the merits of the claims, and the second regarding the reparations that are due.

In the merits section, the IACtHR determined the following key points concerning the RHE. First, the RHE, as a fundamental right for humankind’s existence, is grounded in: (1) Article 26 (Progressive Development) of the ACHR, namely, a right “implicit in the economic, social, educational, scientific, and cultural standards set forth in the Charter of the Organization of American States [OAS-Charter]”;Footnote ³ and (2) Article 11 (Right to a Healthy Environment) of the Additional Protocol to the ACHR in the Area of Economic, Social, and Cultural Rights (ACHR-Protocol) (para. 115). While the RHE’s existence is grounded in Article 26 of the ACHR and the OAS-Charter, Article 11 of the ACHR-Protocol provides its content and scope (paras. 115–16).

Under Article 11, also binding on Peru, “1. Everyone shall have the right to live in a healthy environment and to have access to basic public services. 2. The States Parties shall promote the protection, preservation, and improvement of the environment.”Footnote ⁴

Based on the above-mentioned and UN sources, the IACtHR recognized that the RHE “is of universal interest and is a fundamental right for the existence of humankind” (para. 118).

Second, the RHE comprises substantive obligations involving “air, water, food, ecosystems and the climate” (id.). The IACtHR invoked its previous case lawFootnote ⁵ to emphasize that the RHE “protects the components of the environment, such as forests, rivers and seas and others, as legal interests in themselves, even in the absence of certainty or evidence of risk to individuals,” adding that states are obligated to protect the nature and environment due to their benefits to humanity and importance to other organisms (id.).

Third, the RHE involves procedural obligations relating to access to information, political participation, and access to justice (id.).

Fourth, the RHE underlies or relates to other rights. Air/water pollution may adversely affect a healthy and sustainable environment, affecting the RHE, and the rights to life, health, etc. (para. 119). States have to: (1) adopt laws, regulations, and policies to regulate air/water standards compatible with human and ecosystem health; (2) monitor air/water contamination levels; (3) implement monitoring actions and plans to identify air/water pollution sources; (4) adopt measures for water quality and sustainable water management; and (5) design air/water quality standards, plans, and control measures under the “best available science” and “criteria of availability, accessibility, sustainability, quality, and adaptability, including through international cooperation” (paras. 120–21).

The RHE, particularly in pollution contexts, includes “the right to clean air and water” (para. 125). The right to water involves “access to … water … includ[ing] ‘consumption, sanitation, laundry, food preparation, and personal and domestic hygiene’ and [potentially] … ‘additional water resources based on health, climate and working conditions’” (para. 123). The right to water involves progressive and immediate obligations; and requires states to protect against private individuals’ actions impairing this right and guarantee “an essential minimum of water” (id.). The right to water as an autonomous right, namely, water bodies as environmental elements of intrinsic value (“ecocentric” vision), is closely related to the right to water as a substantive aspect of the RHE (“anthropocentric” vision): the crucial role of water for human survival (para. 124). These two “facets are interrelated, but not in all cases does the violation of one necessarily imply the violation of the other” (id.).

In turn, the IACtHR remarked that the prevention of environmental harm principle is customary and entails the state’s obligation to implement measures to address environmental damage, considering that, “after the damage has occurred, it will frequently not be possible to restore the previous situation,” and that this obligation “must be fulfilled in keeping with the standard of due diligence” (para. 126). Regarding the precautionary principle in environmental matters, this principle: (1) involves measures to adopt when “there is no scientific certainty about the environmental impact” of a specific activity (para. 127); and (2) obligates states to preserve the environment to “[enable] future generations opportunities for development and ensure the viability of human life”—the latter related to the “principle of intergenerational equity” (para. 128).

Finally, and concerning the significance of the above-mentioned principle, the IACtHR pointed out that, regarding environmental damage in the climate crisis scenario threatening species survival, “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). International obligations protecting the environment against unlawful/arbitrary conducts that cause “serious, extensive, lasting and irreversible environmental damage,” especially in the climate change context, are of the greatest importance (id.).

In the reparation section of its judgment, the IACtHR determined the following concerning reparation forms/measures. First, regarding compensatory pecuniary damage, while there was no evidence for precise quantification of amounts disbursed by victims stemming from the facts or income losses, the IACtHR, based on the found violations, concluded that victims incurred expenses and income losses related to medical treatment resulting from health damage plus displacement resulting from harassment as victims had reported, facing the state’s inaction (para. 367). In equity, it ordered USD $15,000.00 as compensatory pecuniary damage for each direct victim (seventy-eight victims) (paras. 367–68). It ordered the same sum (and USD $25,000.00 for vulnerable victims) for compensatory non-pecuniary damage (paras. 376–77): environmental contamination affected victims and impacted their lives, preventing their normal life plan realization, meriting “a different assessment from the damage and suffering caused exclusively by the violations of their personal integrity and health” (para. 375).

Second, regarding restitution in kind, Peru was ordered to establish the levels of air, soil, and water pollution, including a plan to redress environmental damages resulting from heavy metal pollution, which should be based on updated scientific information (paras. 333–34).

Third, concerning rehabilitation, the state was ordered to grant free, timely, and effective healthcare, namely, medical and psychological/psychiatric treatment, to individuals affected by pollution, prioritizing children and elderly persons (para. 338).

Fourth, concerning satisfaction, Peru was ordered to: (1) publish judgment summaries in the official gazette and a major Peruvian newspaper; (2) publish the full judgment on the websites of the Ministries of Energy and Mines, Health, and Environment; (3) issue a judgment-related informative leaflet tailored to minors; (4) disseminate the judgment through the above-mentioned ministries’ social media networks; and (5) offer the state’s apologies in a public ceremony in La Oroya, acknowledging its responsibility for human rights violations (paras. 340–41).

Finally, regarding non-repetition guarantees, Peru was ordered to: (1) harmonize national laws on air quality standards, maintaining levels of polluting metals within the maximum permitted to avoid jeopardizing the environment and human health; (2) organize alert and air quality monitoring in La Oroya; (3) ensure that La Oroya’s inhabitants affected by pollutants can access public healthcare; (4) guarantee that La Oroya mining-metallurgic activities do not breach international environmental standards; (5) educate state officers on environmental matters; and (6) establish an information system on air and water quality in Peruvian mining-metallurgic zones (paras. 346–55).

The La Oroya judgment included a partial dissenting opinion of Judges Sierra Porto and Pérez Goldberg regarding the justiciability of the RHE under Article 26 of the ACHR.Footnote ⁶ They considered that, under treaty interpretation doctrine, the analysis of the effects on the right to health needs to be anchored in the rights to life or personal integrity impaired as a result of the state’s action/omission, rather than in additional references to Article 26.Footnote ⁷

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Overall, the La Oroya judgment makes important contributions to the RHE. Concerning the merits section findings thereof, this can be said. First, the IACtHR in La Oroya Footnote ⁸ has arguably consolidated and fleshed out its approach to RHE as an independent, directly enforceable, and justiciable human right, which Article 26 of the ACHR protects according to the IACtHR. This could be regarded as a key contribution to the construction and consolidation of environmental human rights. Unlike other human rights bodies, the IACtHR combines anthropocentric and ecocentric approaches more explicitly. Furthermore, it provides an in-depth analysis of the contents and nature of the RHE in scenarios where there has been grave and long-term urban pollution. This may positively impact ongoing and future climate litigation within the inter-American system of human rights and beyond:Footnote ⁹ there is increasing litigation concerning the impact of extractive activities on the environment and related rights in diverse countries.

However, the IACtHR’s interpretation and application of the RHE as an autonomous and directly justiciable right under Article 26 of the ACHR still faces some challenges. In La Oroya, the above-mentioned partial dissent evidences so.Footnote ¹⁰ While these dissents could be “formalistic arguments”Footnote ¹¹ as they are confined to the impact on only other rights, the important jurisprudential developments concerning the RHE and its justiciability should be better justified under the legal framework of the inter-American system of human rights. In La Oroya, the IACtHR should have better elaborated on the connection between, on the one hand, the general provision of the progressive development of socioeconomic rights contained in Article 26 of the ACHR, and, on the other hand, the specific and detailed provisions of the RHE itself fleshed out in Article 11 of the ACHR-Protocol. The latter also binds Peru. Yet, as noted, the IACtHR merely invoked these provisions without examining in detail how Article 11 unpacks the much more general statement contained in Article 26 (and, by extension, the OAS-Charter). It could have indicated to what extent and how each Article 11 provision fleshes out Article 26. By more comprehensively connecting its innovative jurisprudential interpretation and application of the RHE with the inter-American human rights instruments adopted by states, the IACtHR’s case law could indeed be more easily followed by states, as Latin American states have increasingly demanded the Court to ground its interpretation in treaty provisions more strongly rather than too “expansive” judicial interpretations. This can also help IACtHR’s judgment implementation. Moreover, this connects with the need for enhanced legitimacyFootnote ¹² and effectivenessFootnote ¹³ that international courts such as the IACtHR look for, especially in the current context where diverse supranational institutions have increasingly been questioned or challenged.

Second, concerning more specific aspects of the substantive contents of the RHE, La Oroya expands the IACtHR’s environmental jurisprudence, as La Oroya seminally focused on air, water, and soil pollution affecting urban areas. This contrasts with IACtHR’s previous cases that mainly concerned Indigenous peoples or communities and deforestation issues resulting from natural resource extraction. Thus, the IACtHR finally addressed the overlooked environmental issues of pollution and did so in light of the due diligence standard to better evaluate the fulfillment of substantive obligations.Footnote ¹⁴

Additionally, in La Oroya, the IACtHR soundly combined ecocentric and anthropocentric approaches to the right to water and its relationship with the RHE. For example, the IACtHR indicated that the state has to “report on possible risks to human health and ecosystem health” (para. 121). While the breach of the right to water as an autonomous right requires that problems in accessing water impact humans, the right to water as a RHE component solely demands that water basis were affected regardless of evidence of or certainty of risks for persons’ rights.Footnote ¹⁵ Thus, the latter follows a more ecocentric approach.Footnote ¹⁶

Third, the IACtHR’s reference to international environmental protection vis-à-vis jus cogens is innovative, but also ambiguous: there were no specific references to state or international practice supporting the jus cogens qualification. While some commentators have seemingly understood that the IACtHR actually referred to “the right to a healthy environment as jus cogens,”Footnote ¹⁷ others have interpreted that it did not find that “the RHE has a jus cogens status, it simply said that it should have.”Footnote ¹⁸ Indeed, there is some important difference between the language employed by the IACtHR’s judgment and the concurring opinion of Judges Pérez Manrique, Ferrer Mac-Gregor Poisot, and Mudrovitsch. While the former indicated that “international environmental protection requires the progressive recognition of the prohibition of such conduct as a peremptory norm (jus cogens)” (para. 129) the latter more assertively or categorically: “emphasize[d] the jus cogens nature of environmental protection”Footnote ¹⁹ and qualified “[t]he protection of the environment as a peremptory norm of international law (jus cogens).”Footnote ²⁰ Furthermore, unlike the IACtHR’s judgment, the said concurring opinion delves into the justification and consequences of the above-quoted jus cogens qualification.Footnote ²¹

Thus, the IACtHR in La Oroya could not fully agree on whether environmental protection/the RHE has already achieved the jus cogens status.Footnote ²² Yet, the IACtHR’s advisory opinion on climate change recently qualified the obligation not to cause irreversible damage to the climate/environment as jus cogens.Footnote ²³ Although the International Law Commission’s list of jus cogens norms does not include environmental protection, this list is “non-exhaustive,” namely, it is “[w]ithout prejudice to the existence or subsequent emergence of other peremptory norms of general international law (jus cogens).”Footnote ²⁴ It could be sustained that, inter alia, the recognition of the environmental protection as a jus cogens norm will depend on, inter alia, whether and to what extent states and international courts are willing and able to come up with such a recognition in a scenario where there has been increasing supranational environmental litigation at diverse international courts.Footnote ²⁵

While the La Oroya judgment reparation findings are important, some critical comments can also be made. First, La Oroya jurisprudential analysis and findings concerning compensatory pecuniary and non-pecuniary damages are largely consistent with the IACtHR’s robust reparation/compensation case law. This jurisprudence has been highly influential across supranational courts, as the IACtHR’s reparation case law has often been invoked.Footnote ²⁶ However, it can be questioned whether the IACtHR’s overreliance on equity for the determination of compensatory pecuniary damage should have been better combined with more specific quantification criteria in La Oroya. There was sufficient (potential) evidence for specific pecuniary damage quantification. Moreover, La Oroya primarily involved pecuniary damage: equity better fits non-pecuniary damage quantification.

Second, despite the importance of the restitution measures ordered,Footnote ²⁷ the IACtHR did not expressly request the state to bring back or at least attempt to restore the situation that existed before the pollution. Whether this is possible has to be established at a later phase: during reparation implementation. Nevertheless, the IACtHR should have required such an obligation of result as a jurisprudential or normative standard rather than only grant measures that seemingly tend to lean toward obligations of conduct (best efforts) for the responsible state. La Oroya’s environmental pollution had already lasted several decades, and the state’s past corrective measures were insufficient.

Third, although rehabilitation measures ordered are necessary and sound, the responsible state was directed to offer healthcare solely via the public healthcare system. Since there are important qualitative differences between private and public healthcare in a developing state like Peru, the IACtHR should have indicated that, if needed or urgent, the responsible state should also afford private healthcare for La Oroya victims. Otherwise, victims may not medically rehabilitate, even with lethal consequences, if they can only access the comparatively precarious public healthcare system of Peru.

Fourth, concerning satisfaction, the IACtHR should have also recommended that private mining companies that contaminated La Oroya ought to apologize publicly. As done in other IACtHR casesFootnote ²⁸ and consistent with UN Reparation Principle 22,Footnote ²⁹ the IACtHR could have additionally ordered the state to: (1) build a memorial/monument to remember the serious environmental damage and related harm on local inhabitants; and (2) punish those liable individuals. These satisfaction measures would specifically redress non-pecuniary or moral harm.

Fifth, the IACtHR could have ordered additional suitable non-repetition guarantees. Based on its reparation jurisprudence in environmental casesFootnote ³⁰ and/or UN Reparation Principle 23, these additional measures may have included mechanisms for preventing, monitoring, and resolving social conflicts that often take place in mining-metallurgic zones, as well as further legislative review and reform on environmental issues and related matters. This is key to achieving the main goal of non-repetition guarantees: prevention of structural or systemic environmental rights violations.

Yet, it is also herein recognized that (over)ambitious reparation awards against states may end up being counterproductive. This is because states could become reluctant to implement certain reparation measures ordered by the IACtHR. However, the IACtHR could have engaged with the reparation jurisprudence of the African Court of Human and Peoples’ Rights in LIDHO v. Cote d’Ivoire, which had discussed reparation forms to redress harm stemming from a major pollution event.Footnote ³¹ Thus, the IACtHR further could both benefit from and contribute toward likely meaningful judicial cross-fertilization so that serious harm inflicted on the environment and on entire populations could potentially be better addressed and redressed. In any event, the La Oroya reparation implementation may be arguably constrained by the particularities of the Peruvian socioeconomic context surrounding the extractive mining-metallurgic sector, whose in-depth analysis exceeded the IACtHR’s mandate. While the IACtHR examined immediate causes of human rights abuses as to Peru’s breaches of environmental and health standards, it neglected “the root causes of structural inequality, ethnic discrimination and extractive economy,” which may obstruct collective reparation implementation.Footnote ³²

In conclusion, the La Oroya judgment constitutes an important legal first mainly in terms of fleshing out the RHE in the context of major urban pollution caused by mining-metallurgic activities as well as designing reparative measures to redress harm inflicted on humans and the environment at the individual and collective levels. Yet, the IACtHR could still refine some aspects of its “green jurisprudence” by, inter alia: (1) better connecting its innovative case law developments with the Inter-American human rights treaty framework; (2) fleshing out and justifying categorizations of international obligations as (potentially) jus cogens norms; and (3) further considering both additional reparation measures that may alternatively/concurrently better redress the damage inflicted and challenges that underlie reparation implementation.