Air Quality Indexes (AQIs) play an important role in translating environmental monitoring data into information that can be understood and acted upon by the public, policymakers, and service providers. In its 2026 report Air quality indexes: key considerations and roadmaps for best practices [https://www.who.int/europe/publications/i/item/9789289062701], WHO Europe examines how AQIs are developed, evaluated, and communicated, with a particular focus on their effectiveness in protecting public health.
The report highlights a growing need to move beyond traditional, compliance-led approaches to air quality reporting and towards health-based, locally responsive systems supported by high-quality, real-time data.
From regulatory reporting to health-based insight
Conventional AQIs are typically calculated using the concentration of the single pollutant that most exceeds its regulatory limit at a given time. While this approach is widely used and relatively simple to communicate, the WHO report notes that it does not adequately reflect the combined health impacts of exposure to multiple air pollutants.
Health-based AQIs, by contrast, are derived from epidemiological concentration–response functions and represent the cumulative short-term health risks associated with several pollutants. The WHO identifies these indexes as better aligned with public health objectives, provided they are built on robust monitoring data and validated for local conditions.
The Canadian Air Quality Health Index is presented in the report as a well-established example of this approach, demonstrating how multi-pollutant data can be integrated into a single, health-relevant metric accompanied by clear public guidance.
The role of monitoring infrastructure and data quality
A central finding of the WHO assessment is that the effectiveness of any AQI depends on the quality, continuity, and transparency of the underlying environmental data. Health-based indexes, in particular, require reliable, high-resolution monitoring capable of capturing real-world exposure patterns across time and place.
This has direct implications for cities, local authorities, building managers, and infrastructure operators seeking to align with best practice. Continuous, real-time monitoring of air quality and related environmental parameters enables more accurate index calculation, supports validation against health outcomes, and strengthens public trust in the information being communicated.
Communication, equity, and local relevance
The WHO report also emphasises that AQIs are not purely technical tools. Their public value depends on effective risk communication and sensitivity to local context. Air pollution profiles, population vulnerability, and patterns of exposure vary widely between regions, urban forms, and indoor and outdoor environments.
Best-practice AQIs should therefore be locally adapted, equity-aware, and supported by communication platforms that make real-time information accessible and understandable to diverse audiences.
Implications for real-time environmental monitoring
For organisations responsible for designing, deploying, or operating environmental monitoring systems, the WHO roadmap reinforces the importance of integrated hardware and software solutions that can support both regulatory reporting and advanced health-based analysis.
Sonitus Systems provides end-to-end environmental monitoring solutions, combining high-accuracy sensors with cloud-based data management and visualisation [https://www.sonitussystems.com/]. Sonitus systems support the continual monitoring of multiple environmental parameters, including indoor and outdoor air quality and noise, with real-time information available through the Sonitus Cloud dashboard. This capability aligns with the WHO’s emphasis on data quality, transparency, and timely public communication as foundations for effective AQIs.
Next steps
The WHO Europe report concludes that health-based AQIs offer significant advantages over conventional approaches, but only when supported by robust monitoring infrastructure, locally relevant data, and clear communication strategies. As air quality management becomes increasingly central to public health, climate policy, and urban governance, real-time environmental intelligence is becoming essential infrastructure rather than an optional add-on.
For more information on Sonitus Systems’ indoor and outdoor noise and air quality monitoring products and services, or to discuss how real-time environmental data can support best-practice air quality indexing, contact the team at
https://www.sonitussystems.com/contact-us