Air Quality Monitoring - Stage 1

01 Make a plan

Review the steps below and make sure you/your department have adequate staffing, resources and authority to carry through with what is required (including quality assurance, data validation and data analysis). 

Ensure that your management is committed to sustaining your efforts beyond your/their tenure. You can get a good overview by reading the resources below.

02 Establish monitoring objectives

Agencies will monitor for different reasons. These include establishing baseline conditions, checking compliance with ambient standards, raising public awareness, understanding source attribution, establishing trends, exposure assessment, calibrating remote sensing data or atmospheric research. Each objective may drive decisions about siting, monitoring approach and the levels of accuracy and precision needed. 

03 Identify potential sites

Siting criteria may differ among countries; however, best practices follow similar principles. Briefly, one should avoid areas with nearby obstructions (e.g. walls or large trees) that impede free air flow, and the sampling inlet should ideally be 1.5-3 m above ground level (close to the typical human breathing zone). 

Next, choose the type of site you wish to monitor. The highest priority is to monitor residential areas of high population density, as we usually monitor air quality to improve human health. Additional monitors may be placed near potential  otspots (e.g. alongside highway roads with heavy diesel traffic) or industrial zones. 

After that, it is good to monitor areas that are upwind of population density or emission sources to establish background concentrations of air pollution. Diffusion tubes can provide useful information on gaseous pollutants levels and can help identify siting needs. The criteria below provide context for detailed site selection, such as avoiding nearby sources and buildings to ensure the location is representative of ambient conditions across the area.

04 Buy your first regulatory-grade monitor and supplies 
and ensure adequate technical support

For jurisdictions with no prior experience with AQ monitoring, it is recommended to buy and deploy a single regulatory grade* (FEM), continuous PM2.5 instrument (usually a beta attenuation monitor or BAM). Such instruments usually require supplies (e.g. filter tapes, which last a month on average), so buy an adequate (1-3 years) supply. 

You may also wish to buy a HEPA filter for zero checks, and a flow verification device. Obtain bids from several vendors and consider price, but also consider customer support for installation, testing as well as ongoing maintenance after installation. This also requires co-located meteorological measurements, a data logger and (optionally) technology to transmit data to a central computer or data server located in department offices. Arranging product support is critical to ensure service and sustainability. Federal Equivalency Method refers to U.S. EPA 40 CFR 58 Appendix D definition of monitors that provide comparable results to Federal Reference Methods, also defined in Appendix D. These instruments have been shown to provide highly reliable results under a range of conditions with accuracy and precision needed for compliance monitoring.

*Federal Equivalency Method refers to U.S. EPA 40 CFR 58 Appendix D definition of monitors that provide comparable results to Federal Reference Methods, also defined in Appendix D. These instruments have been shown to provide highly reliable results under a range of conditions with accuracy and precision needed for compliance monitoring.

05 Adopt installation and calibration Standard Operating Procedures (SOPs)  

Most vendors will provide installation services, but you should ensure that they use US EPA certified or EU Directive test methods to calibrate equipment and ensure it is operational and reporting appropriate values. Standard Operating Procedures (SOPs) should be provided or developed for staff to use for routine operations and periodic maintenance.

06 Adopt validation and Quality Assurance/Quality Control procedures

Establish Data Quality Objectives and then develop quality control and quality assurance plan that ensure you will meet your data quality objectives for the specific measurements. The guidance documents below are designed for sophisticated national networks but are a guide for establishing simpler procedures that work for a single monitor. See for example the EPA Ghana guidance adapted for the Ghana monitoring network.

07 Improve data management

Real-time data should flow to a central computer system with backup redundancy and archive, but many instruments have a USB port for data retrieval and manual storage if internet connectivity and servers are unavailable. In this way data can be transferred manually to a centralized data system.



System design should allow for various types of data (integrated filter mass and chemical speciation analysis) in the future as well as both “raw” and “final” data following validation procedures (see Step 6 above) and associated meta data such as quality flags. Consider the hardware requirements for the system including software licenses and training for staff on their use.

08 Provide training and capacity-building to the monitoring staff

Staff assigned with monitoring roles should be trained on how to use the equipment following the SOPs developed under Step #5. Training is also needed related to quality assurance and quality control procedures described under Step #6 and data management under Step #7. Regular exchanges with other air quality monitoring network, to share best practices and learn about pitfalls to avoid is also crucial to strengthening the capacity of the monitoring staff.

09 Make the data available

It is essential to make the data available to the research community and the public by establishing a data archive that is accessible within a reasonable period and includes appropriate metadata. 

Share data fully and openly: in physical units, with station-specific coordinates, in daily or sub-daily frequency, and in a format that is machine-readable. This facilitates collaboration and innovation across civil society, government and the private sector to support you in solving air pollution. 

Examples include US EPA’s AirNow and Air Quality System (AQS) and other national examples listed below. It is also good to distribute data through outside providers such as OpenAQ and others. (See Public Engagement and Communication guidance for smart-phone apps, website development and public awareness raising).

10 Use the data

One of the biggest mistakes that agencies can make is to collect data and then let it sit on a shelf. The point in collecting AQ data is to conduct a baseline assessment relative to national standards and WHO health based AQ guidelines, so we can quantify the human health impacts of air pollution and make data-based decisions about the steps that can be taken to improve air quality.  

Annual “State of the Air” reports can be an impactful way to raise awareness, support policy and enable decision makers to engage stakeholders on the issue. Or the development of a public health messaging campaign for exposure mitigation (See guidance on Public Engagement and Communications) and development of an Air Quality Management Plan (AQMP) based on an assessment of the data.