Model building a national human biomonitoring programme from the ground up: A framework informed by a comprehensive review of global state-of-the-art practices.

Global chemical production is projected to increase sharply by 2050, intensifying concerns about population exposure and related health and environmental risks. Human biomonitoring (HBM) provides a direct measure of aggregate internal exposure to chemicals and can act as an early warning tool for emerging health risks. There are growing international efforts to strengthen chemicals management and integrated risk assessment, including the EU's One Substance, One Assessment (OSOA) framework. Systematic HBM data are increasingly recognised as essential for translating exposure information into actionable evidence for chemical risk assessment and policy development. Several countries have established national HBM programmes, demonstrating their value for public health, regulatory decision-making, transparency for citizens and chemical safety. Yet many countries still lack such programmes despite having capable laboratories or prior scientific HBM experience. Establishing a sustainable national HBM programme requires coordinated governance, stakeholder engagement, infrastructure, technical expertise, mechanisms for linking science to policy and communication strategies. This study addresses this gap by proposing a holistic and adaptable framework, informed by best practices identified across 14 countries. The framework outlines the key elements required for the establishment and operation of national HBM programmes, including governance structures that facilitate collaboration among relevant stakeholders through either cross-ministerial steering committees or centralised coordinating bodies. It further emphasises systematic chemical prioritisation, standardised operating procedures, quality assurance and quality control (QA/QC), harmonised sample collection and processing, transparent science-to-policy translation mechanisms, integration with existing health surveys, shared infrastructure, international collaboration, and strategic biobanking as essential components for ensuring comparability, cost-efficiency, and long-term sustainability.