Tool 6 - World Health Organization (WHO) and National Air Quality Guidelines


The setting up of air quality guidelines and standards is the basis for controlling and managing urban air quality. Many countries as well as the World Health Organization (WHO) have established air quality guidelines.* These guidelines and standards are set to protect public health and the environment against hazards. Health problems and other adverse effects occur when pollution levels exceed guidelines. Annual mean guidelines and standards are designed to protect the population from regular exposure to high levels of pollution. If the mean daily concentrations are kept low, long-term chronic effects on human health are minimized.

Standards and guidelines often distinguish between short-term and long-term exposure (see TOOL 7). When abnormally high levels of pollution persist for short periods, acute effects may result. Short-term guidelines and standards place limits on pollutant concentrations ranging between 10 minutes to 24 hours.

Air quality guidelines are not standards in themselves. Governments, in the context of prevailing exposure levels and environmental, social, economic, and cultural conditions must adopt them. Therefore, it is necessary to establish to what extent WHO standards are similar or different from the standards applied at national and local levels of countries and cities.

Table 6.1 presents the main air quality guidelines of the World Health Organization (WHO)* as well as some national guidelines. A more comprehensive database containing WHO and country specific guidelines is available in the CD-ROM format as part of WHO's Air Management Information System (AMIS). (Please refer to TOOL 7 for guidance on how to order the CD-ROM). AMIS was produced through the contribution of the GEMS Air Programme by UNEP and WHO and is part of WHO's Healthy City Project.

The guidelines serve to protecting public health from the adverse effects of air pollution and to eliminate or reduce air contaminants known to be hazardous to human health and well-being. The standards also take into account the adverse effects on soils, water, crops, vegetation, human made materials, animals, wildlife, weather, and visibility.

The guidelines represent the current best scientific judgment. Periodic reviews and revisions will be needed as new health data becomes available.

Additional information on guidelines is given in the following:

  • A speech text of WHO on air quality guidelines (included in the WHO CD ROM - Healthy Cities Air Management)
    • Explains the criteria used to establish guidelines
      - Chapter 3 of the WHO's "The Air Guide"
    • Gives a comprehensive overview of WHO guidelines
      - "Air Quality Guidelines for Europe", WHO regional publication Series No. 23
    • Lists guidelines of different European countries

Table 6.1 Air Quality Standards and Guidelines (in µg/m3)

 

 

 

Example:
In summer 2004, the levels of ground-level ozone were high in southern Europe with widespread exceedances of the information threshold value (180 µg/m3), as laid down in the ozone directive (2002/3/EC). The exceedances of the information threshold were similar to earlier years, except for summer 2003, when there was a record number of exceedances. Also the directive's long-term objective to protect human health, 120 µg/m3 of ozone concentration over 8 hours, was extensively exceeded in the EU and other European countries. The target value to protect human health was also exceeded in southern and part of central Europe. The highest levels were reported from Italy and Spain, with a maximum ozone level of 417 µg/m3.

Air pollution by ozone in Europe in summer 2004 (Technical report No 3/2005), published at EEA (European Environment Agency) OPOCE (Office for Official Publications of the European Communities).

 

NOTE:The WHO Air Quality Guideline values are valid as of the preparation of this tool. However, the guideline values for pollutants may have changed during publication of this tool in 2005-2006 and may not be included in their revised forms in this tool.

Please consult the 2nd Edition of the World Health Organization's Air Quality Guidelines at http://www.euro.who.int/air/activities/20050223_4) for updated values. One important update to note is that the WHO no longer specifies a guideline limit value for particulate matte (PM), reflecting recent research which indicates that there is no 'safe' lower threshold for this pollutant.

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