This report analyzes air quality legislation in 194 countries and the EU to assess how well countries have implemented robust systems of air quality governance. It finds that while progress has been made, significant improvements are still needed. Key findings include: 31% of countries lack ambient air quality standards; 43% lack a legal definition of air pollution; and 37% do not legally require air quality monitoring. Only a third have legal mechanisms for managing transboundary pollution. The report outlines a model governance system and finds that countries vary widely in their approaches. It recommends countries strengthen laws by adopting more stringent standards, improving monitoring, clarifying enforcement mechanisms, and increasing public participation and access to information. An international agreement on air quality standards could help address inconsistencies