Vol. 12 No. 6 (June 2002) pp. 310-313
STATE RESPONSIBILITY FOR TRANSBOUNDARY AIR POLLUTION IN INTERNATIONAL LAW by Phoebe N. Okowa. New York: Oxford
University Press Inc., 2000. Cloth$110.00. ISBN: 0-19-826097-0.
Reviewed by Marcilynn A. Burke, Law Center, University of Houston.
Dr. Okowa sets out to determine "the extent to which pre-existing principles of international law can be effectively
applied to transboundaryair pollution" (p. 2). Transboundary pollution involves adjacent jurisdictions or
those in close proximity. In these situations, the source state is emitting pollution that adversely affects another
state or states. Dr. Okowa is not concerned primarily with pollution from a source state affecting a neighboring
state-transfrontier pollution-but rather she is
more troubled by the difficulties posed when multiple states are affected-long-range transboundary pollution. Such
pollution is distinctive because of the "general inability to trace the precise sources of pollutants that
eventually cause damage," (p. 10) because, in large part, of the distances these pollutants are able to travel.
For long-range transboundary pollution, however, she cites more structural barriers to settling disputes, particularly
possible difficulties in joining multiple parties in cases in international for action. Dr. Okowa's study does
not, however, consider what could be called "global pollution", that is, pollution that affects the entire
planet such as global warming, ozone layer depletion, or losses of biodiversity.
Though Dr. Okowa expresses some desire to not distinguish among pollutants in this work, she does recognize the
special issues that arise with radioactive contamination and suggests that our approach to this kind of pollution
necessarily must be different from our approach to oxides of nitrogen or sulfur, for example. Primarily she believes
that the international community should focus more upon prevention of harm by requiring states to exercise a level
of due diligence that is
proportionate to the potential harm caused by radioactive contamination. She also suggests that given the potential
enormity of damage from radiation, it may
be necessary to establish a fund for loss distribution because no one state may be capable of compensating another
state for the damage.
This book is very descriptive. Dr. Okowa reviews court cases, arbitrations, provisions of treaties, pronouncements
of international organizations, and general state practices. She endeavors to bring to the reader the benefit of
her extensive research into these sources of law. Though one can assume that this research produced some well-founded
conclusions, Dr. Okowa's linguistic style sometimes makes it difficult to identify those conclusions concisely
and precisely. She demonstrates
that general principles of international law do prohibit significant transboundary air pollution. But she finds
that these general principles provide inadequate protection. She concludes that procedural requirements upon which
she places great importance as discussed in Chapter 5 have not become a
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part of customary international law. With respect to substantive requirements or standards, the reader presumes
that these also are not a part of customary international law by their very nature. Air quality standards setting
the maximum amount of allowable pollution are necessarily specific and detailed, and absent an absolute ban such
standards would need to be laid out in treaties. Yet as Dr. Okowa reviews treaties in Chapter 2, she finds that
though the treaties represent significant advancement in the regulation of air pollution, they are still quite
general in nature.
Also, presumably because this book is a study of state responsibility in international law, Dr. Okowa considers
only in passing the role that various non-governmental organizations play in the setting of standards of conduct.
Pro-environment and pro-business public interest groups, corporate or industrial entities, green consumers, grassroots
activists, and environmental professionals all play a role in state responses to pollution. To understand more
fully the possible evolution of state
responsibility for transboundary air pollution, it might prove fruitful to consider these non-governmental actors'
influence upon state practice. Dr. Okowa does make reference to the development of international human rights law,
and it could be interesting to expand that comparison to include how these non-governmental actors may be similarly
influencing the evolution of international environmental law.
Dr. Okowa begins the book with a description of the nature, sources, and effects of pollutants that contribute
to transboundary air pollution. The sources of greatest concern are industrial activity, atmospheric nuclear tests,
and accidental radioactive contamination from civilian uses of nuclear power. Though these sources produce many
pollutants, Dr. Okowa focuses upon oxides of nitrogen and sulfur and radiation. One of the most significant characteristics
of these pollutants for purposes of her analysis is the ability of these pollutants to be widely dispersed. She
also introduces in this opening chapter one of the traditional stumbling
blocks to environmental regulation: scientific uncertainty. Uncertainty with respect to sources and effects contributes
in large part to what Dr. Okowa later describes as states' unwillingness to obligate themselves to meeting specific
procedural and substantive standards.
In Chapter 2, Dr. Okowa reviews many of the international treaties that address pollution. She considers global,
regional, and bilateral treaties on sulfur, nitrous oxides, and volatile organic compounds, among others. She also
examines the treaties on notification and assistance in case of a nuclear accident and treaties regarding nuclear
safety. In this chapter, she suggests that the international community must develop environmental standards through
treaties because general customary international law is inadequate to deal with the specific problems of environmental
protection. Dr. Okowa appears to favor treaty regimes as the solution to establishing state responsibility, but
she also recognizes the relative strengths and weaknesses of the treaties currently in force. Notwithstanding the
that international treaties depend on states' voluntary submission and implementation through state governments,
she argues that resources should be devoted to strengthening treaty regimes.
In Chapters 3 and 4 she considers the customary international law principles that are relevant to transboundary
air pollution and radioactive contamination, respectively.
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Dr. Okowa questions to what extent the normative content of the treaties has become a part of customary international
law. With respect to transboundary air pollution, she observes that there are no new specific regimes to address
the issue. Instead she reports on the application and adaptation of existing principles to environmental problems.
Furthermore, she finds that the treaties are more concerned about the prevention or reduction of non-radioactive
pollution than they are concerned about holding states' liable for the damage their various activities cause in
neighboring states. On the other hand, customary international law deals
primarily with liability and not prevention.
In considering the application of customary law to radioactive contamination, she reviews the treatment of atmospheric
nuclear tests by such instruments as the Treaty Banning Nuclear Weapons Tests in the Atmosphere (1963) and in cases
before international tribunals such as the Nuclear Test Cases before the United Nation's International Court of
Justice. She also considers states' responses to the Chernobyl nuclear reactor accident. Though she devotes some
time to discussing the
significance of affected states never formally asserting a claim against the former Soviet Union and the Soviet
Union's denial of responsibility, she cautions that no strong conclusions can be drawn from this isolated event.
States may have never launched formal protests because they were more concerned about continuing their diplomatic
efforts and because even if they had prevailed, they doubted the Soviet Union's ability to compensate them anyway.
Though the basis for liability may be unclear, Dr. Okowa finds "no reason, in logic or principle, why the
accident at Chernobyl should not be governed by the existing rules of international law" (p. 130), notwithstanding
the practical difficulties that she discusses in Chapter 6.
In her discussion of radioactive contamination, she questions whether it is sufficient for a state seeking to avoid
liability to say that it has exercised the requisite due diligence. Instead, given the nature of the potential
harm from a nuclear reactor accident, for example, states arguably should be held to a strict liability standard.
With strict liability, the state would be responsible regardless of the precautions that it took. Alternatively,
a state would be responsible only if it was negligent in conducting its activities or recklessly disregarded the
potential risks of its activities, for example. Dr. Okowa suggests that because of the difficulties of proving
causation and the inability to agree on the appropriate level of due diligence and standards of liability, states
may opt for diplomatic rather than legal solutions as they do in many contexts other than environmental protection.
She then turns in Chapters 5 and 6 to states' procedural and substantive obligations. The procedural aspects of
interest are environmental impact assessments, exchange of information, notification of proposed projects, and
consultations with affected states. In so doing, she returns to the treaties she introduced in Chapters 2 and 3
and she also considers various arbitral decisions regarding breaches of procedural requirements. She also considers
whether certain procedural obligations are a part of customary international law and concludes that (despite the
views of various commentators and jurists) with the exception of notification in emergency
situations, procedural requirements have not become a part of customary international law. The substantive concerns
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are not limited to this problem but are rather the classic issues within tort law. Here she discusses the different
possible types of breaches and damages, the problems with proof of causation, and apportionment of responsibility
among multiple states. Though some writers emphasize cooperation and non-judicial methods in the face of the particular
difficulties of proving causation, Dr. Okowa argues that there is s still a role for state responsibility or liability.
In Chapter 7 she considers the available remedies before international and national tribunals and follows in Chapter
8 by exploring states' compliance with treaty standards. In her discussion of the possible remedies available from
international tribunals, Dr. Okowa stresses the primacy of injunctive or declaratory relief as opposed to compensation
for environmental harms and the tribunals' apparent uneasiness with such remedies. With respect to national tribunals,
she argues that requiring states to exhaust local remedies may be inefficient and otherwise inappropriate when
the disputes are regional in scope.
In the end, Dr. Okowa calls for (1) establishing air quality and emission standards, (2) creating mechanisms for
monitoring compliance with those standards, (3) strengthening international institutions and treaty regimes to
enforce the obligations, and (4) adapting existing dispute resolution mechanisms to adjudicate more effectively
disputes involving multiple states. With respect to nuclear accidents, she suggests that because losses may exceed
any given state's ability to pay, the international community should set up a fund to distribute losses among states.
This work is ambitious in its coverage and sheds considerable light upon the current state of affairs and the difficulties
of asserting a claim for damages arising out of transboundary air pollution. At times the discussion of general
legal concepts is difficult to follow and may mislead the reader into thinking that the problems with standards
of liability, proof of causation, joinder of multiple parties, apportionment of responsibility among multiple parties,
and fashioning appropriate remedies
are unique to claims involving transboundary air pollution. Instead of devoting as much time to discussion of these
general principles, greater attention could have been given to how these claims present additional complexities
such as the effect of scientific uncertainty upon states' willingness to submit to the authority of international
This book will be most useful to environmental scholars who are unfamiliar with international law. It would also
be of interest to international law scholars who are initially considering international responses to pollution.
For those who are more experienced in international environmental law, the book may be valuable in that it collects
in one place summaries of most of the relevant treaties and judicial and arbitral opinions.
Copyright 2002 by the author, Marcilynn A. Burke