Harmonizing environmental policy across borders: A case study of China–Laos regulatory disparities

Environmental standards are crucial for managing transboundary resources, especially in regions undergoing rapid economic integration. This study explores the environmental governance gap between China and Laos, whose bilateral relationship has intensified through major infrastructure projects like the China-Laos Railway. Despite growing interdependence, little research has examined the comparative environmental standards between the two countries. This study addresses that gap by analyzing their regulatory frameworks on air quality, water resources, and soil contamination. Findings indicate substantial disparities in pollutant thresholds, regulatory stringency, and implementation mechanisms. In air quality, China adopts a dual-tier system to accommodate regional pollution levels, while Laos follows WHO guidelines but lacks enforceable limits for key pollutants such as SO₂. In water standards, Laos enforces stricter chemical oxygen demand (COD) thresholds for pristine water but allows higher nutrient concentrations, whereas China imposes tighter limits on heavy metals like mercury due to its industrial legacy. For soil contamination, Laos maintains more stringent arsenic limits but permits significantly higher chromium levels, reflecting the economic influence of its mining sector. These inconsistencies pose challenges for cross-border environmental management in shared ecosystems like the Mekong River basin, increasing the risk of regulatory arbitrage and hindering data harmonization and joint governance. The study concludes that effective transboundary environmental governance will require harmonized pollutant standards, coordinated monitoring systems, capacity-building efforts, and unified environmental impact assessment methods to ensure sustainable development along corridors like the Belt and Road Initiative.