The New EU Ambient Air Quality Directive Addressing Environmental Protection Agencies (EPAs)

The European Union (EU) has taken a decisive step towards improving ambient air quality with the approval of the new EU Ambient Air Quality Directive by the EU Council on October 14, 2024. The revised directive prioritizes the health of EU citizens by setting stricter air quality standards for pollutants, with the goal of meeting these standards by 2030, more closely aligned with World Health Organization (WHO) guidelines. The next steps involve the publication of the directive in the EU’s Official Journal, after which it will enter into force 20 days later. Member states will then have two years to transpose the directive into national law.

A significant aspect of the directive is the mandatory inclusion of ultrafine particle (UFP) measurements, which are now required across all EU member states as part of their local monitoring strategies.

Key Changes in the New EU Directive for Ambient Air Quality

The new directive significantly expands the scope of ambient air quality monitoring to include both particle number (PN) concentration and particle size distribution (PSD) measurements. For the first time, EU member states are required to incorporate these advanced particle metrics into their local air quality monitoring networks, in addition to the previously mandated measurements such as PM10 and PM2.5. This change addresses the growing concern over the health impacts of UFPs, which have been linked to respiratory, cardiovascular, and neurological diseases.

Key highlights of the directive include:

1. Inclusion of Particle Number (PN) Measurements
   Under the new directive, member states must monitor ambient particle number concentrations in addition to mass-based metrics like PM10 and PM2.5. PN concentrations provide a more detailed assessment of the presence of UFPs, which are especially harmful due to their ability to penetrate deep into the respiratory system.
2. Mandated Particle Size Distribution (PSD) Monitoring
   PSD monitoring provides critical data on the range and distribution of particle sizes in the atmosphere. The directive emphasizes the need to measure PSD, ensuring that air quality monitoring networks capture detailed information on the composition and behavior of particulate matter, including the smallest, most harmful particles.
3. Alignment with European Standards: EN 16976 and CEN/TS 17434
   The updated directive requires PN and PSD measurements to be conducted in line with the recently revised European standards:
   • EN 16976 (published in September 2024) outlines the methods for measuring ambient particle number concentrations. This standard provides guidance on sampling methods, data handling, and particle conditioning to ensure accurate and consistent measurements across Europe.
   • CEN/TS 17434 defines technical specifications for measuring particle size distribution in ambient air. This technical specification ensures that all member states use harmonized measurement techniques, enabling consistent data collection and cross-country comparisons. Note this technical specification is currently under revision for being transposed into a full standard within 2025.

Advancements in Technology for Air Quality Monitoring

The adoption of this directive necessitates advanced instrumentation capable of accurately measuring PN concentrations and PSD. Condensation Particle Counters (CPCs), such as the TSI Model 3750-CEN10, have become the most widely used instruments to continuously measure particle number concentrations in the ambient atmosphere. They are highly sensitive and capable of detecting particles as small as 10 nanometers, making them ideal for monitoring UFPs. CPCs can be used as standalone devices or integrated into more complex systems like Scanning Mobility Particle Sizers (SMPS™), which measure particle size distribution by classifying particles based on their electrical mobility. SMPS™ systems provide detailed PSD data, along with integrated total particle number concentrations, making them invaluable for understanding the composition of ambient aerosols.

Integrating New Technologies into Monitoring Networks

The directive encourages member states to integrate these advanced technologies, such as CPCs and SMPS™, into their existing air quality monitoring networks. By leveraging these tools, countries can not only comply with the new requirements but also significantly improve their understanding of air pollution, especially the presence and effects of UFPs.

Looking Ahead: A Milestone for Air Quality and Public Health

The new EU Ambient Air Quality Directive is a critical step toward protecting public health and the environment. By mandating the inclusion of PN and PSD measurements, the directive ensures that air quality monitoring becomes more comprehensive and capable of addressing the challenges posed by ultrafine particles. These changes will provide policymakers with better data to inform decisions, improve regulations, and ultimately reduce the health impacts associated with air pollution across Europe.

TSI is ready to help EPAs implementing PN and PSD measurements into existing monitoring networks. Our experts will guide you from choosing the right state-of-the-art instrumentation to final installation and data integration. Learn more about our solutions and contact us today.