The Vienna Air Monitoring Network
Good Practice UN-Habitat 1996

Lead Idea

Air quality measurements taken by the City of Vienna provide information for assessing immissions in the capital. Where legally determined threshold concentrations are exceeded, recommendations on the efficient implementation or introduction of measures to reduce emissions are made based on an analysis of the comprehensive data collected.

Starting Position

Air quality in the City of Vienna is affected by frequently changing framework conditions regarding emissions and the general weather situation, as well as by various chemical and physical processes in the air influenced accordingly which result in immissions which vary greatly in location and time. Since 1984, the Department for Environmental Protection of the City of Vienna has been responsible for planning the measurement network, maintaining the measuring stations, and for the management, archiving and administration of the data collected. Air quality measurement data have been made available by other institutions since the end of the 1960s. The office for the air quality measurement network, set up in 1991, has conducted evaluations and produced related publications, particularly with reference to the exceeding of legal limit values for the protection of the population and vegetation as contained in the smog alarm law (Smogalarmgesetz), the ozone law (Ozongesetz), the immission protection law-air (Immissionsschutzgesetz-Luft) and various EU Directives.

Methods

The Vienna air quality measurement network enables continuous analysis of air pollution. The data collected on air quality are published daily, as a service to the city's residents. Measurements are taken every ten seconds at each air monitoring station and converted into an average value for each minute. These data can be downloaded every three hours. The daily average values for air quality are prepared in the form of a graph for each month, with the data being made available as video text, via a telephone service, on the radio, in daily newspapers and on the Internet. Four displays in public spaces show the values for SO2, NO2 and CO2 as well as ozone and smog values on a nine-point scale from "very good" to "poor". These values are based on the criteria of the Austrian Academy of Sciences. An important aspect of the publication of air quality data is the simultaneous recommendation of counter-measures and motivating the population to contribute themselves to improving air quality in their city. The measurement data produced by the Vienna air quality measurement network provide valuable information as to whether efforts to achieve a targeted reduction in emissions of pollutants have had a corresponding positive effect on the capital's air quality.

Experiences

Measurements of air quality have been taken in the City of Vienna for over 30 years. Over this relatively long period of time, many of those generating emissions of pollutants have carried out measures to reduce their emissions. Flue gas purification plants have been installed on urban power stations, or the plants have been switched to burn natural gas, a gradual reduction in the sulphur content of fuels has been sought, district heating has been used increasingly in order to reduce emissions from fires in the home, and the Section 57a test (ß57a-Überprüfung) with a waste gas check has been introduced.

Transfer Potential

In addition to the practical measures encouraged by the monitoring of air quality, the network has had a positive effect on public awareness, in particular. This system can be transferred to any urban area.

⇒  The Vienna Air Monitoring Network in the UN database