I. The Source of the Right: A Moral or Legal Right?

One of the more confusing and difficult aspects of the right to breathe clean air pertains to its source as a human right, bringing the classical jurisprudential debate between natural and positive law to the forefront. Certainly, the paramount rationale for considering the right to clean air as a legal right is its inclusion in legal texts with a corresponding obligation of its protection by the states and the ability to rely on it in the courts. For instance, the second part of the German Basic Law (Germany’s Constitution), “The Federation and the Länder,” sets forth that, for the sake of future generations, the State shall protect natural foundations of life “by legislation and, in accordance with law and justice, by executive and judicial action.” ^{Footnote 5} Similarly, Article 24 of the African Charter on Human and Peoples’ Rights stipulates that “all people shall have the right to a general satisfactory environment [favorable] to their development.” ^{Footnote 6} The promotion and protection of this right is guaranteed by Article 30 of the same Charter, which established the African Commission on Human and Peoples’ Rights to undertake this duty.Footnote ⁷

The positivistic approach is not, however, the only one that makes the right to breathe clean air a human right. Admittedly, it also contains natural law underpinnings, which prescribe the right’s universality, inalienability, and immunity to the non-existence of codified principles. As aptly remarked by Swanson and Hughes, “clean water and clean air are believed to be ours by birth; we somehow assume that such important and fundamental rights are protected by law.” ^{Footnote 8} It thus remains beyond doubt that the source of the right to clean air has deeper roots than its recognition in legal acts, and the best evidence of that is the long-lasting cognizance thereof among different communities. ^{Footnote 9} The environmental and health conscience had surely transmogrified into a moral claim for a dignified life before the 1972 United Nations Conference on the Human Environment (UNCHE), which declared that “man has the fundamental right to freedom, equality and adequate conditions of life, in an environment of a quality that permits a life of dignity and well-being.” ^{Footnote 10} The travaux préparatoires of the Committee of the UNCHE corroborate that the need and conviction about the right to the adequate environment had already permeated the international community. ^{Footnote 11} In the same vein, the ethical importance of the basic human entitlement to clean air had certainly materialized in the Portuguese nation before 1976, when Portugal, as the first country, introduced to its constitution the “right to a healthy and ecologically balanced human environment.” ^{Footnote 12} The incidence of the moral right before its formal enactment is quite common and applies to different areas of human rights law. By way of comparison, the moral awareness and the ensuing struggle for granting voting rights to women, and the advocacy for abolishing slavery, both predate their formal acknowledgement in legislation. As Trajković propounds, there is no establishment of human rights without accepting moral values, which represent something durable and per se constitute the binding force of human rights. ^{Footnote 13} For this very reason, classical Bentham’s legal theory of rights—which stipulates that only a substantive right is the child of law, ergo, a real right—suffers from conceptual and empirical drawbacks and can hardly be accepted within the framework of human rights law. ^{Footnote 14} Moreover, as some authors suggest, the standard court enforcement procedure is not necessary for the evidence and realization of the right, especially when one has in mind the moral right. ^{Footnote 15} Other strategies, involving the proliferation of information, activities of social movements, ethical tribunals, and local cooperation have likewise proved beneficial. Be that as it may, for the moment, it suffices to state that the right to clean air is both a moral and a legal human right. ^{Footnote 16}

II. The Category of Human Rights: A Third Generation Right?

Further uncertainty has arisen as to the classification of the right to clean air. Downs put forward the assertion that a right to clean air—here as a component of the right to clean environment—should be viewed as a third-generation right, on the basis that it is “necessary to facilitate the fulfilment of first and second-generation rights which already guarantee basic rights and freedoms.” ^{Footnote 17} Vasak, who coined the term “solidarity rights,” believes that the right to clean air belongs to this category, as it can only be achieved by common efforts of all who participate in society: States, individuals, and other private and public entities. ^{Footnote 18} Yet, both formulations do not withstand criticism. Namely, the third category of human rights might be classified as anachronistic, legacy- devaluing true human rights that might cause additional confusion within the already complex system of human rights. It should also be noted that many scholars nowadays see the right to clean air as a fundamental human right, which is indispensable and interdependent. ^{Footnote 19} By the same token, the Inter-American Court on Human Rights, in its Advisory Opinion on the environment and human rights, regarded the right to clean air as a fundamental human right.Footnote ²⁰ In relation to the solidarity argument, one could rightly argue that the idea of solidarity is necessary for the attainment of all human rights, not only those rights which fall into the third category.

III. Timescale: A Present-Day or Future Right

Regarding the timescale, the focal point is whether the right to breathe clean air should be perceived only from the current, or also the future, perspective. National constitutions regulate this matter differently. For instance, while the South African Constitution in Article 24 guarantees the right to an environment that is not harmful to health and the well-being of present and future generations, many other constitutions do not refer explicitly to the future generations. In fact, jurisprudence and human rights discourse typically focus only on the rights of existing humans.

Nowadays, however, people tend to be more aware of the vulnerability of future generations to perils resulting from current environmental decision-making and are more focused on sustainable development and intergenerational equity. This is the correct standpoint, as it reflects the idea of the preservation and continued use of res communis omnium. ^{Footnote 21} The U.S. scholars have of late advanced a new so-called “atmospheric trust theory” that relies on the ongoing Juliana v. United States of America lawsuit claiming that generations to come have the right to a clean atmosphere. ^{Footnote 22}

Yet, the reference to future generations should be construed as a duty of those who are alive rather than as a right of those who still have not acquired the right. Such a duty can, interalia, be exercised in court litigation, as noted by the Supreme Court of the Philippines. Having recognized the standing of forty-four children who opposed cutting the rainforest via their logging permits, the court observed that their “assertion of the right to a sound environment constitutes, at the same time, the performance of their obligation to ensure the protection of that right for the generations to come.” ^{Footnote 23}

Consequently, the right to breathe clean air should be construed as a right of the present generation, which implies a constant duty towards persons not yet born.

IV. An Individual or Collective Right?

Another aspect related to the right to breathe clean air is whether it should be considered as an individual right—owed to a person—or a collective right—owed to all people or humankind—. Even though it virtually does not exist as a separate right, the parallel can, again, be drawn to the right to a healthy environment. As mentioned, Article 24 of the African Charter indicates that “all people shall have the right to a general satisfactory environment” which assumes a collectivist approach. The right to the atmosphere (aër in Greek and Latin) has been categorized as one of the legal commons since Roman times. The Institutes of Emperor Justinian proclaimed that “[b]y the law of nature, things can be everybody’s: these things which are naturally common to all are the air, flowing water, the sea and the seashores.” ^{Footnote 24} With regard to draft guideline 3 discussed by the Sixth Committee of the General Assembly at its seventy-first session, the Polish delegation proposed that the last sentence of paragraph (7) of the commentary to draft guideline 3 should be replaced with the following phrase: “In this context, it should be noted that not only is the Paris Agreement acknowledging in the Preamble that climate change is a common concern of humankind, but also that ambient air quality is a common concern of humankind, according to [World Health Organization] Ambient Air Quality Standards and Guidelines.” ^{Footnote 25} Humankind as a whole is thus the recipient of the protection. ^{Footnote 26} Nowadays, the collective standpoint gains prominence, although there are authors who still tend to consider the right to clean air as an individual right. ^{Footnote 27} In fact, the majority of states’ constitutions provide for individualized rights, but the examples of collective rights are not uncommon. ^{Footnote 28} The most appropriate answer to the posited question would, therefore, be that, although the right may protect people individually, it also requires collective action and cooperation, and thus possesses both dimensions.

V. The Correlation Between a Substantive Right and Procedural Rights

The next aspect concerns the need to articulate the differences between the substantive right to clean air and other correlated procedural rights. Although there exists a temptation in conflating both aspects in line with the “expansive approach” put forward by Rodriguez-Rivera, it must be observed that procedural rights constitute a separate corpus of rights, which, in truth, exert a substantial impact on the realization of the said right. ^{Footnote 29} David Boyd, UN Special Rapporteur on “the Issue of human rights obligations relating to the enjoyment of a safe, clean, healthy and sustainable environment” outlined in his report the catalog of procedural rights. The catalog includes the right to education and initiatives that raise awareness on air quality and related problems; access to environmental information; freedom of expression, association, and assembly; participation in the assessment of proposed projects, policies, and environmental decisions; and affordable, timely access to remedies. ^{Footnote 30} Recent trends of restricting the activities of externally funded NGOs or targeting environmental defenders in developing countries impair the achievement of environmental justice, the protection of the substantive right to clean air, and the environmental rule of law in general.

Procedural environmental rights are present in national and international regulations. To date, more than thirty national constitutions have included multiple procedures aimed at securing environmental protection. Article 35(2) of the Czech Republic’s Constitution, for example, stipulates that “everybody is entitled to timely and complete information about the state of the environment and natural resources.”Footnote ³¹ At the international level, procedural environmental rights are enshrined in such documents as the Rio Declaration on Environment and Development, ^{Footnote 32} the Convention on Access to Information, Public Participation in Decision-Making and Access to Justice in Environmental Matters (Aarhus Convention), which, apart from individuals, is also addressed to associations, ^{Footnote 33} and the EU Air Quality Directive. Sommermann’s study has shown that the Aarhus Convention belongs to one of the most frequently quoted international treaties in administrative law decisions of domestic courts in Europe. ^{Footnote 34} The implementation of judicial review standards—such as the availability of procedures, their adequacy, costs, and timeliness—turned out to be the most problematic point for states. ^{Footnote 35}

It is not uncommon that while establishing a violation of the substantive right, adjudicating bodies refer to procedural rights. For instance, in Social and Economic Rights Action Centre and the Centre for Economic and Social Rights (SERAP) v. Nigeria, the African Commission, besides establishing a Nigerian violation of the right to a satisfactory environment (Article 24 of the ACHPR), noted that Nigeria failed to conduct a social and environmental impact assessment, inform people about health and environmental risks, or include those concerned with decision-making bodies. ^{Footnote 36}

Irrespective of such intermingling practices, it is necessary to note that apart from the African Continent and a handful of states, the right to breathe clean air—in the form of a right to a healthy environment—is nonjusticiable, and it is actually procedural rights that largely contribute to environmental protection instead. Nevertheless, it remains highly disputable whether procedural rights are sufficient to ensure a healthy and ecologically sound environment. ^{Footnote 37} Shelton argues that an independent right to breathe clean air is indispensable. ^{Footnote 38} The recognition of the substantive right would add to environmental protection by placing limits “on the outcome of the process.” ^{Footnote 39} The substantive right to breathe clean air would, therefore, guard against such situations when policy decisions—even in keeping with procedural guarantees—would be insufficient in securing human and environmental health. In other words, it would be a minimum enforceable guarantee of environmental quality.

One can thus postulate that both substantive and procedural rights are needed, although procedural rights might be especially helpful in resolving conflicting situations. For example, procedural rights can be used as a balancing power between the substantive right to breathe clean air and other competing human rights, such as the rights to development, private property, or food.

I. Autonomy: Part of a Greater Structure and the Interrelationship with Existing Human Rights

Possibly the most important issue revolving around the right to clean air is its autonomy. Indeed, apart from a handful of acts, such as the Constitution of Pennsylvania and the Constitution of Massachusetts, the right to clean air virtually does not exist as a stand-alone provision, whether in national constitutions or international legislation. ^{Footnote 40} The right to clean air is conventionally conceptualized as a component of the broader right to healthy, clean, or ecologically balanced human environment—along with the right to safe water and sanitation, healthy and sustainable food, a safe climate, and healthy biodiversity and ecosystems. ^{Footnote 41} The words “healthy,” “clean,” “sound,” and “ecologically balanced” shall be construed as synonyms and are often used interchangeably. For instance, the Argentine Constitution in Article 41 provides that residents “enjoy the right to a healthy, balanced environment,”Footnote ⁴² the Mongolian Constitution in Article 16 refers to the “right to a healthy and safe environment,”Footnote ⁴³ Article 23 of Montenegro’s Constitution stipulates that “everyone shall have the right to a sound environment,”Footnote ⁴⁴ and Article 30 of Nepal’s Constitution sets forth that “every citizen shall have the right to live in a clean and healthy environment.“ ^{Footnote 45}

Although it holds true that such taxonomy neither makes the right to clean air less of a fundamental human right than other components nor impossible to distil from the broader structure, it stands to reason that the right would acquire a clearer meaning and avoid potential misinterpretations if it was articulated separately. Because most of the constitutions refer to the cluster right of “a healthy environment,” it is unlikely that they will redefine their approach and secure individual articles for each component of the cluster right in their supreme legal acts. New laws, however may specifically invoke the right to clean air, as is the case with the New York State Constitution, where the proposed constitutional amendment S 2072/A 2064 inserted a new Section 19, recognizing the inalienable and self-executing right of New Yorkers to clean air.Footnote ⁴⁶ In a similar way, at the international level, where the right has not been recognized yet, the UN Special Rapporteur for the first time dissociated more patently the right to clean air from the right to a healthy environment in his last 2019 report.Footnote ⁴⁷

The question of the autonomy of the right to breathe clean air arises also in relation to its interdependence with other human rights. This is particularly evident in adjudication, as courts tend to subsume the right to breathe clean air under the right to life or the right to health. In Subhash Kumar v. State of Bihar, the Supreme Court of India ruled that the right to life is a fundamental right under Article 21 of the Indian Constitution and includes “the right of enjoyment of pollution-free water and air for full enjoyment of life.” ^{Footnote 48} The Nepalese and Pakistani Supreme Courts took a similar position, ruling that environmental rights are embedded within the constitutional right to life. ^{Footnote 49} In Europe, the European Court of Human Rights (ECtHR)—given the absence of the right to clean air (a healthy environment) in its European Convention on Human Rights—has often interlinked the right to clean air with other Convention’s rights, especially the right to life (Article 2), the right to private and family life (Article 8), the right to an effective remedy (Article 13), and the right to peaceful enjoyment of possessions (Article 1 of Protocol No. 1). In Oneryildiz v. Turkey, a case concerning a methane explosion on April 28, 1993 near the Ümraniye municipal rubbish tip which caused the death of thirty-nine people, the ECtHR ruled that Article 2 imposes “a positive obligation on States to take appropriate steps to safeguard the lives of those within their jurisdiction.” ^{Footnote 50} In Fadeyeva v. Russia, the Court established the violation of the right to private and family life and ruled that there was “sufficient nexus between the pollutant emissions and the State,” ergo, that Russian authorities had not undertaken adequate measures to secure the dignified life of people living around the Severstal steel plant. ^{Footnote 51} In the most recent case, Portillo Cáceres and Others v. Paraguay, the UN Human Rights Committee, a quasi-adjudicatory body, ruled that the mass use of agrotoxins by large agribusinesses in Paraguay—which had led to poisoning and death of the affected population— violated their rights to life, privacy, family, home, and to an effective remedy. ^{Footnote 52} As observed by the Committee, although the right to breathe clean air is not enumerated in the International Covenant on Civil and Political Rights (ICCPR), “implementation of the obligation to respect and ensure the right to life, and in particular life with dignity, depends, inter alia, on measures taken by State parties to preserve the environment and protect it against harm, pollution and climate change.” ^{Footnote 53} The Committee stressed that there exists an “undeniable link” between environmental protection and human rights. ^{Footnote 54}

In truth, it is also possible to approach the correlation between clean air and other human rights from another, opposite perspective. Namely, that the exercise of human rights is essential to achieving good air quality. ^{Footnote 55} When the people who may be affected by activities and proposed policies can freely participate in the environmental decision-making process, their societies are much more likely to have strong environmental protections. In other words, the unimpaired enjoyment of human rights, including the right to information, education, access to justice, as well as the freedom of assembly and expression, are vital to securing and maintaining adequate air quality. ^{Footnote 56}

Being both a part of the cluster right and substantially correlated with other human rights is one of the greatest challenges to the “individuality,” or “purity,” as Collins suggests, and, by implication, to the normativity of the right to clean air. Following Collins, the right in its “pure” sense should be able to create entitlements beyond those contained in other existing rights. ^{Footnote 57} Thus, in a hypothetical scenario when a polluting factory causes harm or death to people, the concerned people should be in a position to rely not only upon the well-established right to life—and the duty of the state to protect and promote life—but also invoke the infringement of an independent, free-standing right to breathe clean air.

II. The Ambiguous Content of the Right (I): How “Healthy’’?

The content of every right should have a clear meaning, outline the juridical scope, and identify right-holders and duty-bearers. Unfortunately, the right to clean air certainly does not belong to the corpus of rights with substantial legal clarity and certainty. Inasmuch as the definition of air does not raise concerns—it is the gas mixture that forms the Earth’s atmosphere—the question of what “adequate quality” means, and who should determine it, remains disputed. Namely, should adequate quality be left to the domestic legislator or should it be determined at the international level? More importantly, should it be solely based on scientific data or should socio-economic determinants be considered as well?

The elementary definition of adequate air quality, from an anthropocentric perspective, would mean that the air should be healthful, fulfilling human rights standards. Following Bryner, a clean or healthy, ergo, adequate, air presupposes the absence of pollution—which would compromise ecological integrity or threaten irreversible harm. At a minimum, it must be “sufficient for human life, food production and to maintain the ecosystem services and biological diversity that are familiar to humans.” ^{Footnote 58}

Providing a more sophisticated or technical definition of decent air quality is highly challenging. Given that countries and international organizations invoke different standards related to air pollution limits, the question surfaces whether it is at all possible to conclusively state what clean air means, a fortiori, whether the right to clean air is universally applicable. For example, the new EU Air Quality Directive sets out the annual level for particulate matters PM_2,5 at 25 µg/m³ and PM₁₀ at 40 µg/m³, ^{Footnote 59} while the World Health Organization guidelines prescribe the annual limits for PM_2,5 to be 10 µg/m³ and for PM₁₀ 20 µg/m³. ^{Footnote 60} Similar disparities relate to the allowed concentration of other air pollutants, such as ozone, sulphur dioxide, nitric oxide, mercury, and others—as well as the time allowance for the excess. ^{Footnote 61} It is particularly worrying that eighty states have no air quality standards and guidelines at all—which, in consequence in their cases—may lead to total obfuscation of the term “clean.”Footnote ⁶²

What further obscures a common content of the right to clean air is the creation of groups, which require particular care, and hence, better air quality. In his recent report, the UN Special Rapporteur underlined that women, children, the elderly, and indigenous peoples are particularly affected by bad quality air. ^{Footnote 63} This essentially means that for various people, differing levels of air quality are considered “decent.”

III. The Ambiguous Content of the Right (II): Primary and Secondary Subjects

The right to breathe clean air does not have specified recipients. It is, therefore, possible to approach the question of its subjects from two angles: Anthropocentric, claiming that only human beings are the holders of the right, and ecocentric, presupposing a wider range of living species.

Nevertheless, it stands to reason that human beings are the primary recipients of the right to breathe clean air. The anthropocentric thesis of the right to clean air is insofar valid as the limits set out in legal regulations are adjusted to human needs and humans are allowed to seek redress if the right is violated. ^{Footnote 64} For instance, the Romanian Constitution recognizes “the right of every person to a healthy, well-preserved and balanced environment.”Footnote ⁶⁵

Yet, the very phrase “well-preserved and balanced” may imply the duty of not causing harm by pollution to other living organisms. This is patently underscored in Angola’s Constitution, which calls on the state to “adopt measures necessary for the protection of the environment and the species of flora and fauna” and to “maintain ecological equilibrium.”Footnote ⁶⁶ Against this background, it is reasonable to assume that other living species, such as animals, are likewise addressees of the right to breathe clean air. ^{Footnote 67} They could, though, be defined as secondary subjects. ^{Footnote 68}

With reference to legal acts that appertain to the secondary subjects of the right to clean air, one could mention the EU Air Quality Directive, which, in Article 1, aims at “defining and establishing objectives for ambient air quality designed to avoid, prevent or reduce harmful effects on human health and the environment as a whole.” In the same spirit, the Rio Declaration on Environment and Development, the 2030 Agenda for Sustainable Development, and the Paris Agreement all highlight that “social and economic development depends on the sustainable management of [the] planet’s natural resources” and that the proper protection of biodiversity, ecosystems, and wildlife is needed. ^{Footnote 69} The Heads of State and Government and High Representatives, while deciding on seventeen new global Sustainable Development Goals, declared that they wish for a world where “humanity lives in harmony with nature and in which wildlife and other living species are protected.” ^{Footnote 70} The “wildlife,” “ecosystems,” and “livelihoods” thereby become subjects of international concern and enjoy the protection against contaminated air. Certain countries, like New Zealand or India, have even recognized intrinsic rights of nature, conferring legal personhood upon the Te Urewera National Park and the Ganges River respectively, which means that their rights are legally protected and can be vindicated. ^{Footnote 71} Thus, although human beings remain the basic subjects of the right to breathe clean air, other living organisms benefit from the right as well.

However, the more pertinent aspect which impinges on the normative status of the right is the lack of clear ascertainment of duty-bearers and right-holders in potentially contentious cases. The Constitution of Serbia provides that ‘’everyone shall have the right to a healthy environment” and that “everyone, especially the Republic of Serbia and autonomous provinces, shall be accountable for the protection of environment.”Footnote ⁷² Within traditional human rights framework, it is usually a state that is obliged to guarantee and respect human rights.Footnote ⁷³ With respect to the right to breathe clean air, the catalog of duty-bearers appears to be larger, while their responsibility is lessened in view of the vague temporal obligations and the possibility of a multiplicity of culprits. Moreover, if the right to breathe clean air was considered individually, without recourse to other human rights, then the class of potential claimants would likewise be broad, and, as aptly observed by Lewis, “it would be difficult to identify a person or group with a sufficient interest in the environmental harm to bring a claim’’ when environmental harm occurs.Footnote ⁷⁴ Therefore, the relationship between the duty-bearers and right-holders seems to be quite unsettled.

IV. The Ambiguous Content of the Right (III): The Scope of the Right

The determination of the geographical scope of the right to clean air is complicated. In particular, it is not clear whether the right to clean air is an international, or mainly a regional or national right. The main argument for rejecting universality to the right to clean air, in the positivist sense, is that it still has not been recognized by the United Nations as a universal right. ^{Footnote 75} Namely, neither basic human right documents, such as the 1948 Universal Declaration of Human Rights or 1966 UN Covenants on Human Rights, nor any other subsequent treaty, mention it— either as an autonomous right or as a part of the right to a healthy environment. It is also debatable whether the right has acquired the customary international law character, as there has been very little in the way of consistent state practice.^{Footnote 76} As the UN Environment report found, despite a thirty-eightfold increase in environmental laws since 1972, a failure to fully implement and enforce these laws is readily evident.^{Footnote 77} The inductive method informing the formation of an international custom also fails on account of opinio juris, which is the conviction that custom is mandatory. The absence of the right to clean air at the international level confirms that states are quite resistant in taking up such a new obligation and prefer to consider it under a domestic, often non-justiciable, legal framework.^{Footnote 78} Therefore, the postulates of some authors trying to attribute the customary law character to the right—by studying the implantation of the environmental impact assessment (EIA) in the world^{Footnote 79}— or even arguing that it is becoming a jus cogens norm (binding upon the whole international community), are excessive and perhaps even misleading.^{Footnote 80} On the one hand, it is probably best to say that the right to clean air in the positivist meaning is yet to emerge at the international level. On the other hand, the right to clean air certainly exist globally as natural law, as noted in the preceding section.

In view of that, it must be assumed that the right to clean air predominantly boils down to a national level. However, as mentioned, the right at a national level, if it exists, is not meaningfully adhered to. This then raises the question as to whether the right even has a proper domestic law character.^{Footnote 81}

Another relevant question pertains to the sphere of the right to breathe clean air, most notably, whether the right applies only outdoors or also indoors. In the majority of cases, the air is comprehensively protected only in the public sphere, in spite of the evidence that indoor pollution is likewise very dangerous to human health and generates high economic costs. ^{Footnote 82} For example, the EU Air Quality Directive regards only ambient air quality, stipulating that workplaces are excluded from its scope, “where provisions concerning health and safety at work apply and to which members of the public do not have regular access.” ^{Footnote 83} Similarly, the Serbian Law on Air Protection sets forth that the air should be construed as the air in the troposphere in the open spaces, excluding closed areas. ^{Footnote 84} Consequently, the indoor air is either only protected by the employer, educational institution, or another establishment—or, in the case of private houses—is not subject to any protection at all. In the latter instance, members of the household, including children, can hardly assert the right to breathe clean air, especially if people smoke in the house or use stoves fueled by kerosene, biomass (wood, animal dung, and crop waste), or coal. Fortunately, in recent years there is a growing tendency of extending legal protection to people, especially children, from indoor air pollution. The prohibition of smoking in restaurants and the Australian Public Health (Tobacco) Act 2008, which forbids smoking in a car with a child under sixteen years of age, are good examples thereof.

V. The Enforcement Conundrum

The enforcement of the right to clean air is undoubtedly one of the weakest sides of the right. At the international level, the right remains unenforced, for the simple reason that there still exists no right to clean air on the international level—which could be subject to the scrutiny of specially entrusted supervisory bodies. Yet, the right can be executed in a different “international” context, especially as a state’s responsibility for causing environmental harm—in this case, a State serves as an agent of the people concerned. The milestone case in that regard is the Trail Smelter case between the United States and Canada, then a dominion of the United Kingdom, decided by the Arbitral Tribunal. ^{Footnote 85} The award established the pecuniary responsibility of the Consolidated Mining and Smelting Company (COMINCO), whose smoke had caused damage to forests and crops in the area surrounding Washington. The arbitration not only coined the polluter pays principle (PPP) in international law, but also affirmed the customary principle of “good neighborliness” in bilateral arrangements between neighboring states. ^{Footnote 86} With time, state obligations associated with the maxim sic utere tuo ut alienum non laedas (use your own property in such a manner as not to injure that of another) changed the focus from monetary compensation to prevention: Due diligence, environmental impact assessment, equitable and reasonable utilization of the atmosphere, and international cooperation. ^{Footnote 87} This is predominantly so because compensation in case of harm often “cannot restore the situation prevailing prior to the event or accident.“ ^{Footnote 88}

Unfortunately, states are rarely held accountable for not obeying international environmental law principles which are conducive to securing clean air, both for legal and factual reasons. First and foremost, states have proved to be extremely resistant in submitting environmental law to the compulsory jurisdiction of a court; states need to agree for a court to resolve a potential dispute. Furthermore, the scope of such a dispute would be virtually limited to adjacent territories as it is very difficult to prove the responsibility of a State for long-distance air pollution. Also, given the enhanced contribution of private businesses to environmental degradation, it remains unclear what type of liability should be attributed to states, and in particular, whether it should be liability ex delicto, liability sine delicto stricto sensu, or liability sine delicto lato sensu. ^{Footnote 89} Over and above, the international treaty regime concerning long-distance pollution is very fragmented. State obligations are, interalia, reflected in the Geneva Convention on Long-Range Transboundary Air Pollution (CLRTAP) and protocols thereto, the Association of Southeast Asian Nations (ASEAN) Agreement on Transboundary Haze Pollution, and the International Convention for the Prevention of Pollution from Ships (MARPOL), which concentrate on cooperative and facilitative measures rather than enforcement procedures. Even the potential treaty on air protection, on which the ILC is currently working, will produce little coercive enforcement effectiveness, in view of the fact that states decided to exclude from its scope such matters as “the liability of states and their nationals, the polluter-pays principle, the precautionary principle, common but differentiated responsibilities, and the transfer of funds and technology to developing countries, including intellectual property rights.” ^{Footnote 90} Therefore, it is not difficult to agree with Yamineva that international law fails to adequately address air pollution and secure the human right to clean air. ^{Footnote 91}

The situation seems to be rather gloomy on the regional level too, where, although the right is more represented, it remains largely non-justiciable. The San Salvador Protocol to the American Convention on Human Rights, for instance, reads that “everyone shall have the right to live in a healthy environment,” but it does not include the right in the short list of economic, social, and cultural rights whose breach may be the subject of a claim to the Inter-American Commission on Human Rights. ^{Footnote 92} Both the Arab Charter on Human Rights and the ASEAN Human Rights Declaration include the right to a “healthy” (Arab Charter) or “safe, clean and sustainable” (ASEAN Declaration) environment as an element of the right to an adequate standard of living, but neither instrument creates oversight mechanisms that can receive complaints in case of a violation of the right. ^{Footnote 93} The right is also not guaranteed by the European Convention on Human Rights and any protocol thereto—which makes the European Court of Human Rights incompetent in that regard. The Court has, in fact, referred to clean air in its judgments, but the violation concerned Article 2 (right to life) and Article 8 (right to private and family life) of the Convention, as previously mentioned. ^{Footnote 94} Likewise, the EU primary law does not expressis verbis mention the right to clean air, albeit such right is inferred from secondary law, in particular from the obligation of Member States to assure adequate air quality, specified in the Air Quality Directive. The European Court of Justice in the landmark Janecek case declared that:

The Janecek judgment was later confirmed in ClientEarth2, where the Court upheld the right of standing of individuals and NGOs before a national court in order to enforce the Air Quality Directive. Claimants also have the right to a legal remedy, in other words, the right to require the adoption of a plan, and have the right to demand judicial scrutiny of that plan. ^{Footnote 96} Very recently, the Court of Justice of the European Union ruled that the Air Quality Directive demands air pollution limits (in Brussels) to be assessed at monitoring stations where people’s exposure to pollution is the greatest, not with an average across an area, thereby setting a good precedent for the rest of Europe. ^{Footnote 97}

The EU Member States are also controlled by the European Commission, which can refer a State to the European Court of Justice (ECJ) and impose very high financial fines. For instance, in 2018, the ECJ ruled that between 2007 and 2015, Poland had regularly exceeded the daily limit values for PM₁₀ concentrations in thirty-five out of forty-six zones, whereas the annual limit values for such concentrations were exceeded in nine zones. ^{Footnote 98} In March 2019, the EU Commission decided to take Italy to the ECJ for failure to obey the NO₂ limit values in the ambient air prescribed in Directive 2008/50/EC. ^{Footnote 99}

At the national level, the right to clean air is present in the legal acts of the vast majority of countries—mainly as the right to a healthy environment—but regrettably, it remains largely unactionable in and of itself. That being said, the violation of the right is mainly established in conjunction with other human rights. For instance, the district court in Warsaw in December 2018 ruled that smog restricted personal rights of a famous Polish actress, in particular, the freedom of movement and the right to privacy, and ordered the State Treasury to pay 5000 PLN in compensation. ^{Footnote 100} Earlier, citizens and NGOs sought a writ of mandamus in Nepal’s Supreme Court against a marble factory which emitted smoke, dust, sands, and minerals, polluting air, land, and water—risking both the life and property of the local population. The court, in its ruling, relied on Nepal’s constitutional provisions guaranteeing the right to life—noting, however, that it in large measure depends on healthy air. ^{Footnote 101}

Lastly, it is worth emphasizing that many of the environmental rights, including the right to breathe clean air, face adjudication challenges. Vindication of the right to clean air is particularly exacerbated by matters relating to the need for technical expertise, the quantum of evidence needed, and costs to be borne by a state. Hurdles of litigation also relate to the balance between other human rights, such as the right to work and social security.Footnote ¹⁰²

All things considered, the ‘’piecemeal’’ enforceability substantially undermines the normative character of the right to breathe clean air. Although some authors claim that enforceability is not a decisive criterion in establishing and acknowledging the existence of a human right and that human rights supervisory bodies assessing states’ compliance with their human rights obligations are enough to satisfy the “enforceability requirement,” ^{Footnote 103} it is more plausible to side with Handl, who asserts that, at this stage, we cannot talk about the new generic human right to clean air.Footnote ¹⁰⁴