Air Quality Monitoring - Stage 3

01 Revisit monitoring objectives

By stage 3, the monitoring objectives for your network may have changed, for example if your jurisdiction implements source attribution guidance, then additional objectives to support that effort need to be considered [See Source Attribution Guidance Stage 1 and Stage 2]. Given that you may be using manual samplers to collect and archive filter samples in parallel (see source attribution guidance), it is a good time to revisit your air quality monitoring objectives, data quality objectives (DQOs) and procedures to ensure your siting and network strategy is still fit for purpose. Additionally, there may be several other AQ Monitoring objectives to consider, such as the ground-truthing of remote sensing data to support hotspot identification or for exposure assessment, the use of monitoring data to validate AQ models, and to support public communication efforts. 

02 Revisit network strategy and design

Based on your review of air quality monitoring objectives in Step 1, re-examine your monitoring data and network design to determine if you have monitoring gaps (e.g. can you identify new hot spots or industrial clusters that lack regulatory monitors?), identify additional monitoring and/or analysis required (e.g. chemical speciation of filters collected for source apportionment), determine if new instruments are needed for pollutants of emerging concern (e.g. ultrafine particles, black carbon, PM oxidative potential, ammonia), establish the viability of integrating remote sensing data and, finally, review your siting strategy to capture key source categories such as industry or transportation sources. Consider whether one or more sites with additional/enhanced monitoring should be established that can serve as core sites for chemical speciation and source apportionment (i.e. having many species and parameters co-located) and which could also serve as a sensor calibration/evaluation facility.  Adding these sites could help to move your network design closer toward that of a US NCORE or EU supersite network design.  Consider addition of SLCP/GHG monitoring (e.g. black carbon and methane) and source apportionment-specific sites (e.g. PM chemical composition), and establishment of acidification networks, if applicable. 

03 Implement revised network strategy and design

Depending on your choices and decisions under Steps 1 and 2, it is time to implement a revised network strategy.  In addition to new monitoring objectives that may require co-location of monitors (e.g. locating gas monitors or BC monitors at PM2.5 compliance sites), new sites may be needed for PM or gas-species compliance monitoring with additional residential, traffic, hotspot, regional-scale or background sites. Identify these new sites and acquire new samplers/instrumentation as per the revised, expanded and strengthened network design incorporating relevant guidance from subsequent steps and other relevant areas of AQM (e.g. see Source Attribution guidance). 

04 Integrate remote sensing data

When managing air quality, leveraging satellite products (also called remote sensing data) can significantly enhance your efforts. These tools can complement local monitoring networks by providing broader spatial coverage to improve exposure estimates and identify potential pollution hotspots that may require additional compliance monitoring. By integrating satellite data, you can also refine air quality forecasts, but the satellite data products must be ground-truthed to ensure agreement with ground-level measurements for increased accuracy. Making your ground-level data (regulatory grade or LCSs with metadata) publicly accessible enables satellite-operating agencies to calibrate their products effectively and validate their findings against real-world conditions (despite being somewhat different than what is measured on the ground, e.g., aerosol optical depth instead of PM2.5. Collaborating with these agencies not only strengthens your air quality management strategies but also promotes a more comprehensive understanding of pollution dynamics across your airshed (which can span multiple jurisdictions, including neighboring countries). Even if direct collaboration is not feasible, many hydromet and remote sensing datasets are available publicly. Ultimately, harnessing a combination of satellite and ground-level data fosters more informed decision-making and more effective air quality interventions. 

05  Integrate chemical speciation and enhance sample collection for source apportionment

As your monitoring program progresses to Stage 3, it's essential to consider setting up a dedicated analytical chemistry laboratory for local analysis of filter samples which collect PM2.5 (and potentially PM10 as well). Start by reviewing guidance on source attribution [See Source Attribution guidance Stage 1, Step 5] to ensure your team effectively collects filter-based PM2.5 samples that complement and help validate continuous PM2.5 data, in addition to supporting PM source apportionment studies, to enable an understanding beyond total mass of fine particles, but the speciated composition, which helps to identify the source of pollution. Setting up a dedicated laboratory involves several key steps: secure an appropriate space for the lab, procure necessary equipment, and develop Standard Operating Procedures (SOPs) alongside audit protocols to ensure quality and consistency in analyses. This also involves significant expense, which is why it has been deferred to Stage 3, but also may be a reason to establish this capacity at a national/federal level.

To reduce the labor intensity associated with daily filter changes, explore upgrading to multi-channel or sequential samplers, such as the Met-One SASS or SuperSASS, or the URG Dual Sequential Fine Particle Sampler (or similar devices). These advanced systems allow for efficient and regular sampling by automating filter changes (e.g. changing the filter collection channel every 24 hours), easing the workload on monitoring staff while maintaining data integrity. By implementing these strategies, your lab will be better equipped to provide timely and accurate analyses, ultimately enhancing the effectiveness of your air quality management initiatives. 

06 Enhance QA/QC and data management

Enhance quality assurance (QA) and quality control (QC) protocols for your air quality (AQ) monitoring programs by establishing distinct standards and processes for verifying the accuracy, reliability, and quality of data collected (e.g. semi-validated or fully validated chemical speciation results or validation of the filter collection processes). Consider implementing periodic third-party audits to ensure that your QA/QC processes are effective and align with various applications, such as providing semi-validated data for real-time public access and fully validated data for model validation. Additionally, focus on the validation of sample collection methods for accurate source apportionment [See Stage 1, Step 5 of Source Attribution guidance]. 

Review your data management systems to incorporate redundancy and robust backup procedures, safeguarding against data loss. Moreover, prioritize ongoing training for staff on equipment operation and proper handling techniques related to QA/QC protocols. This training will ensure consistency in procedures and enhance the overall quality of the data collected, ultimately leading to more reliable insights into air quality trends and sources. By adhering to these practices, you will strengthen the integrity and credibility of your AQ monitoring efforts. 

07 Expand and enhance data analysis efforts

To effectively analyze air quality monitoring data and ensure regular reporting to the public, establish a clear data processing workflow that includes data validation, quality control (see prior step) and analysis methodologies (e.g. consider establishing the routine publication of a “state of the air” report that is included in staff job descriptions). Utilize user-friendly visualization tools to present findings in an accessible format, emphasizing key metrics such as pollutant levels, trends, and health advisories. Regularly update the community—consider monthly or annual reports—that summarize findings and their implications for public health [coordinate with communications staff implementing Public Engagement and Communications guidance Stage 3, Steps 2 and 3]. Encourage public engagement by participating in stakeholder consultations [Step 4] for questions and discussions. This transparency fosters trust and enhances public understanding of air quality issues and their impact on health and the environment. 

08 Establish a data sharing policy

Establish a procedure for translating raw measurement data into a calculated multi-pollutant AQI for public dissemination and establish a data sharing policy for both validated raw-data and public AQI calculation methodologies.

See Public Engagement and Comms guidance Stage 3, Steps, 4, 5 and 10, as communications staff will likely be the ones who develop public messaging around AQ data, establish the AQI and actually disseminate findings, but AQ monitoring staff are likely the ones who would perform the AQI calculations based on cutpoints determined by department management.  Specific data sharing arrangements can be worked out with academic partners for research purposes.

For jurisdictions subject to the Convention on Long-Range Transboundary Air Pollution (CLRTAP), a framework for exchanging information and data related to air quality and emissions between participating countries is mandatory. This policy aims to facilitate collaboration, improve understanding of air pollution, and support the development of effective strategies for reducing transboundary air pollution.  Key aspects of this framework (which may also be relevant and useful for jurisdictions NOT subject to CLRTAP) can be found in the 1979 LRTAP convention linked below. 

09  Ensure real-time public access to air quality monitoring data

Ensure that the general public, academic partners and key stakeholders have access to all semi-validated continuous data. See if you can receive approval to post data on public platforms such as OpenAQ or IQAir. This can enhance your public engagement efforts being carried out under Public Engagement and Communications guidance.

Some jurisdictions are subject to treaties or protocols that mandate routine reporting, such as the European Convention on the Long-Range Transport of Air Pollution (CLRTAP), which has an online reporting hub that is linked below.  

For effective public communication, use Data Visualization Techniques such as graphs, heat maps, and dashboards that display real-time information. Engage the public with interactive platforms that allow users to explore air quality data. Providing clear and accessible analyses on an annual basis empowers stakeholders to make informed decisions and encourages community involvement in air quality issues.