[en] Pollution caused by airborne particulate matter (APM) in several urban areas has become worse due to economic activities, rapid population growth, urbanization and industrialization. APM can cause serious problems with respiratory, cardiovascular, and even mortality. Air pollution is also a global phenomenon with air transport taking place across countries in a few days and around the globe in a few weeks. Pollution emitted from one source can easily cross international borders and impact any place it travels through. Because of its transboundary nature, air pollution is now being recognized as a regional problem with a serious impact on human health. To address air pollution problems, the analysis and monitoring of APM through the regional cooperative framework is needed. Several cooperative modalities have been promoted under various regional projects. The IAEA’s technical cooperation programme enabled Member States to apply advanced nuclear analytical techniques (NATs) as a unique characterization tool to assess APM pollution, with the objective to gather information and data which can help decision-makers to develop workable strategies and take sound measures to improve air quality in the region. Several cooperative modalities have been used through these regional projects, including knowledge sharing on NATs through mentorship (training and workshops, fellowships, scientific visits and expert missions), networking, research resource units (RRUs), common use of advanced laboratory facilities, as well as support for publications in conferences, symposia and seminars. These cooperative tools have significantly improved the skills of scientists at a regional level and facilitated the accessibility to sophisticated techniques and facilities available in advanced member countries, and increasing the end-user engagement in using the results to design effective strategies and policies for abatement of air pollution, as well as to strengthen regional collaboration between Member States. Several publications and databases obtained have raised the awareness of the usefulness NATs and the greater use of them in environmental sciences. These cooperative modalities should be maintained and can be further improved by increasing government commitment in financial support and attracting stakeholders, summarizing the results and technical process regularly in technical documents, increasing the scope of mentorship and coordination and expanding networking for the new member countries to further consolidate and sustain the culture and spirit of regional cooperation and mutual assistance. (author)