SUMMARY OF THE KEY ISSUES IN ASSESSMENT

It is well known that air pollution concentrations in many European cities are high enough to affect people’s health. Measures to improve the air quality are necessary, and air pollution abatement strategies must be developed (see the section on “planning and measures”). This is required by the EU Air Quality Directives (see the section on “legislation”).

The first step in any structured activity to work with the air quality is to assess the present situation regarding the air pollution concentrations, and at what level they are compared to air quality limit values, as well as compared to guidelines from for example the World health organisation. The assessment involves first and foremost to measure the air pollution concentrations. Assessment techniques also include the use of air pollution models (mathematical physics based techniques to calculate the pollution concentrations based upon data on emissions, meteorology (e.g. wind) etc.) Assessment methods like modelling are also necessary in order to predict what the future air quality might be, on the basis of projected development of the city and its population, the technological developments of vehicles, industrial processes, etc.

This section on air pollution assessment has two main subsections:

• Air Quality Monitoring methods
• Air Quality Assessment tools and methods

The guidance in the topic descriptions is to a large extent based upon the requirements to monitoring and assessment that are set out in the EU Air Quality Directives.

Air quality monitoring methods

The subsection on monitoring methods includes topics describing how to design urban air quality monitoring networks, how to locate monitoring stations, and description of measurement and monitoring methods.

  • Air quality monitoring is potentially a very expensive activity, both in terms of investment in equipment, and in terms of manpower for their operation and maintenance. Thus, a few monitoring stations are usually established, which are supposed to reflect and represent the urban air pollution situation. Thus, their location is very important.
  • Descriptions are given of methods to measure the compounds SO2, NO2, CO, ozone, lead, PM10, PM2.5, heavy metals, benzene and PAH.
  • The quality of the monitoring data is very important, so that there is a correct basis for determining the needs for measures and abatement activities. There is a topic describing data quality (QA/QC) procedures.

Air quality assessment tools and methods

The subsection on air quality assessment tools and methods has topics on assessment by monitoring as well as modelling, and various aspects of the air quality assessment procedure, such as:

  • Separating between the local contributions to the air pollution as compared with what comes in from outside the city,
  • Air quality indicators, to simplify the message of “how is the air pollution in the city?”,
  • Assessing the emissions,
  • How to model air pollution,
  • Development of future scenarios of development, and actual procedure for assessment of present and future air pollution,
  • Short-term air quality forecasting (“tomorrow’s air pollution”).

    • The air quality assessment work for urban areas soon becomes quite complicated, to comply with all the requirements set in the air quality Directives, as well as local needs for assessment of impact of plans and measures, and to satisfy the needs of the citizens for information. Software systems for urban air quality management (air quality management systems) are available. A topic describes the concept and typical contents of such systems, as well as lists many available systems.

    The “assessment” section of the INTEGAIRE guidance should offer the reader shortly explained, concrete recommendations on state-of-the-art procedures of how to measure and assess air pollution. This will provide the basis for proceding with the questions on what to do to achieve the needed improvement so as to provide air for the citizens that does not present a health risk.

    The section refers to a lot of examples from several cities on their own experiences on monitoring and assessing their air quality. Other cities can learn from these experiences. “What to do” in terms of plans and measures is the subject of that part of the guidance.


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