CLRTAP: Working Group on Effects (WGE)

The WGE promotes international cooperation on research into, and the monitoring of, the impacts of air pollutants on human health and the environment. The FOEN coordinates Switzerland’s contributions.

The scientific activities of the CLRTAP Working Group on Effects (WGE) are carried out by six international cooperation programmes (ICPs) plus a working group focusing on health-related impacts of air pollution (Task Force on Health).

The FOEN supports and coordinates the delivery of data and other contributions by Switzerland. It represents Switzerland within the WGE and is also involved in the Task Force on Health. 

ICP Waters (programme for the evaluation and monitoring of the effects of air pollutants on rivers and lakes)

The studies conducted by this programme form the basis for the documentation of the effects of cross-border air pollution on aquatic ecosystems.

They show that international agreements aimed at reducing air pollution have successfully contributed towards the improvement of the chemical and biological status of bodies of water.

In Switzerland, the monitoring programme is currently examining the mountain lakes and high-altitude stretches of rivers and streams in the canton of Ticino, which is coordinating the associated tasks.

ICP Materials (programme for studying the effects on materials)

This programme operates a European network of sites at which various materials are exposed to the influences of air pollutants in order to study their impacts in combination with natural factors (weathering).

The collected data are used for determining the ratio between dosage and effect, as well as for documenting trends relating to impacts and the effectiveness of air pollution control measures.

EMPA (Swiss Federal Laboratories for Materials Science and Technology) represents Switzerland in this programme.

ICP Modelling and Mapping (programme for modelling and mapping critical loads and levels)

The goal of this programme is to evaluate the harmful effects of air pollutants transported over long distances on a variety of receptors such as forests, agricultural crops and (semi-)natural ecosystems (e.g. moorlands, species-rich natural meadows and pastures). Evaluations are carried out with the aid of ecological critical loads and levels. The programme delivers data relating to the geographic distribution of the sensitivity of the studied ecosystems and concerning the extent of damage attributable to air pollutants in Europe.

The resulting data are used for developing spatially differentiated air pollution control strategies while simultaneously verifying the success of the implemented measures aimed at reducing emissions.

The FOEN participates in this programme together with other specialised institutions.

 ICP Forests (programme for evaluating the impacts of air pollutants on forests

The main objectives of this programme are to monitor the status of forests in Europe and enhance the level of scientific understanding of the cause/effect relationships between observed damage and stress factors. Here, atmospheric deposition is regarded as a decisive impact factor.

In Switzerland, the corresponding studies are carried out within the scope of the following programmes: Long-term Forest Ecosystem Research, Sanasilva and National Forest Inventory of the Swiss Federal Institute for Forest, Snow and Landscape Research (WSL).

ICP Vegetation (programme for the evaluation of the impacts of air pollutants on natural vegetation and agricultural crops)

This programme studies and evaluates the impacts of air pollutants on agricultural crops, wild plants and forest trees. It is focusing in particular on the impacts of ground-level ozone and the atmospheric deposition of heavy metals and nitrogen on vegetation. The programme encompasses the following studies:

  • Impacts of combined substance inputs (e.g. ozone and nitrogen)
  • Impacts on biodiversity
  • Modification of impacts through climate change

In Switzerland, the corresponding studies are being carried out at the Agroscope Reckenholz-Tänikon research centre, the University of Basel Institute of Botany, the Institute for Applied Plant Biology and the Swiss Federal Institute for Forest, Snow and Landscape Research.

ICP Integrated Monitoring (Program for the Integrated  Monitoring of Air Pollution Effects on Ecosystems)

The objective of this program is to assess and predict the impact of air pollutants on ecosystems (or catchments), including the impact on flora and fauna. This is achieved by simultaneous observation of physical, chemical and biological parameters at a given location from a long-term perspective. Switzerland is represented in this program with a project of the University of Applied Sciences of the Canton Ticino (SUPSI).

 Task Force on Health

The Task Force on Health is under the leadership of the European Centre for Environment and Health (ECEH) and the World Health Organisation (WHO). It evaluates the health impacts of air pollutants and long-range transboundary air pollution.

The main objectives here are to quantify the health risks and contribute towards the process of defining priorities for the orientation of future strategies for monitoring and reducing air pollutants.

Further information


Last modification 30.01.2019

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