Every year, the residents of northern Thailand face a daunting reality – the seasonal haze pollution that shrouds their skies.

Chiang Mai has earned the unfortunate distinction of being one of the world’s most polluted cities, with the crisis peaking during March and April each year. This haze is a product of open burning in agricultural areas in Thailand and neighboring countries. Faced with this dire situation, action was taken earlier this April when 10 citizens, including a child, filed a lawsuit against Thai government agencies at the Chiang Mai Administrative Court for their failure to address transboundary pollution.

Chiang Mai during the annual haze season. Photo credits Chalefun Ditphudee, EarthRights International.

Recently, I attended the 3rd ASEAN Environmental Law Conference in Bangkok, which took place on August 16-18, 2023. During the conference, Watchalawalee Kumboonreung, a lawyer actively involved in the lawsuit mentioned above, spoke about the challenges of the case. She explained the issue of transboundary air pollution in Thailand and how it underscored government agencies’ inaction to protect human rights by addressing environmental challenges. Furthermore, this case highlighted the pressing need for adaptive domestic laws and regulations to keep pace with the ever-evolving environmental landscape.

We brought the case before the court because people in northern Thailand have suffered from PM 2.5 daily for many years. They were affected by air pollution within a country and a transboundary haze from neighboring countries. We sued the government agencies because they ignored duties under the laws to protect human rights and mitigate the air pollution problems.

Watchalawalee Kumboonreung

Before the conference in Bangkok, I also attended another significant seminar. The Faculty of Law at Chiang Mai University, in collaboration with the International Commission of Jurists (ICJ), Community Resource Centre Foundation (CRC), and EarthRights International, organized an academic seminar on August 7, 2023. The seminar was titled “Extraterritorial Human Rights Harms: Surveying the Body of Knowledge.” It served as a platform for dialogue, exploring the latest developments in domestic and international laws, and looking into jurisprudence concerning access to justice and remedies for extraterritorial obligations. The discussions transcended the borders of Thailand, encompassing other countries in the Mekong region grappling with similar challenges.


During the seminar, I had the privilege of listening to experts unpack the complexities of transboundary pollution.

Transboundary issues and pursuit of justice

Sanhawan Srisod of ICJ highlighted how technology, digital transformations, and climate change have blurred geographical borders. Transboundary air pollution, which affects northern Thailand yearly, is a prime example of an issue that transcends national boundaries. This phenomenon extends to other issues in the Mekong region, including the environmental impact of dams, which caused irregularities in river flow and negatively affected countries in the lower basin. It is important to note that issues arising from one country can have a ripple effect, affecting other countries as well.

Millions of people depend upon the Mekong River for their livelihoods. Photo credits The Mekong Butterfly.

Haze and dams are transboundary issues where a company’s operations in one country impact another. Another major transboundary issue is where a company’s investment in a host country leads to negative consequences within that host country. One case presented at the seminar, Lungowe v Vedanta Resources, demonstrated how communities in Zambia took legal action against a company in the United Kingdom after its subsidiary, an operator of a copper mine, devastated their communities. This instance of communities accessing remedy through legal ways in the court of the company’s home country is relatively rare as companies often use jurisdictional firewalls to avoid responsibility.

Xayaburi Dam and the sugarcane plantation cases

Sor Rattanamanee Polkla of Community Resource Center Foundation presented major transboundary issues and emphasized the challenge of building confidence among affected individuals to engage with human rights protection mechanisms and navigate the complexities of conflicting laws.

One landmark case discussed was the Xayaburi Dam, which marked the Mekong region’s first transboundary litigation. This case involved a Thai company investing in Laos, leading to concerns about the environmental impact and power purchase agreements. The legal challenges in this case revolved around the interpretation of domestic law and the potential impact on affected communities.

Xayaburi Dam. Photo credits International River.

The sugarcane plantation case in Oddar Meanchey, Cambodia, was another example. In this instance, a Thai company registered a subsidiary in Cambodia to secure concessions for sugar plantations. Two representatives of 700 affected families filed a lawsuit against the parent company in Thailand. This case raises questions about the accountability of parent companies for human rights violations committed by their subsidiaries abroad.

The interplay of environmental and human rights laws

Dr. Marcos A. Orellana, the United Nations Special Rapporteur on Toxics and Human Rights, discussed the interface between international environmental and human rights laws. He stressed the importance of the duty not to cause transboundary harm, a fundamental obligation in international environmental law. This perspective was exemplified by the 2017 Inter-American Court of Human Rights advisory opinion, which extended jurisdiction to encompass situations where individuals are adversely affected by pollution from another state’s environment. This broadening of scope highlights the interconnectedness of international environmental law and international human rights protection.

Dr. Pichamon Yeophantong, chairperson of the U.N. Working Group on Business and Human Rights, underscored the role of countries in setting expectations for domestic and foreign companies to respect human rights across their operations. The Xayaburi Dam case served as a case in point, illustrating the complex interplay between human rights and environmental protection.

Call for collective action

Protests outside the Chiang Mai Administrative Court in April 2023, during the filing of a case against the government. Photo Credit Wanna Tamthong.

The challenges posed by transboundary air pollution and corporate accountability in the Mekong region demand a collaborative, transnational approach. The frequent absence of accountability exemplifies a critical failure of the U.N. Guiding Principles on Business and Human Rights. As they enter their second decade of implementation in 2031, the third pillar, Access to Remedy, remains the “forgotten pillar”. Under a voluntary framework, governments disregard their duties and companies ignore their responsibilities as they cause harms across borders.

We must instead put in place both binding and extraterritorial measures to hold companies accountable and uphold human rights. Governments and the private sector must work together to protect the environment and human rights, implementing measures that respect and safeguard the rights of all affected individuals, regardless of national borders. Governments must enact laws that make human rights due diligence mandatory and allow communities to sue parent companies and transboundary polluters in the court of the company’s home country as well as wherever the harms occur. This is absolutely essential in mitigating the Mekong region’s pressing environmental threats and making access to remedy an actionable right.