Working Group on Effects

Early in the discussions on the Convention on Long-range Transboundary Air Pollution it was recognized that a good understanding of the harmful effects of air pollution was a prerequisite for reaching agreement on effective pollution control. To develop the necessary international cooperation in the research on and the monitoring of pollutant effects, the Working Group on Effects (WGE) was established under the Convention in 1980 and held its first meeting in 1981. The Working Group on Effects provides information on the degree and geographic extent of the impacts of major air pollutants, such as sulphur and nitrogen oxides, ozone, volatile organic compounds, persistent organic pollutants, heavy metals, particulate matter, including black carbon, and ammonia on human health and the environment. Its six International Cooperative Programmes (ICPs) (on ForestsWatersMaterialsVegetationIntegrated Monitoring and Modelling and Mapping) and the Task Force on Health identify the most endangered areas, ecosystems and other receptors by considering damage to human health, terrestrial and aquatic ecosystems and materials. An important part of this work is long-term monitoring. The work is underpinned by scientific research on dose-response, critical loads and levels and damage evaluation.

The Working Group meets annually to discuss the results of the international programmes and the current and future needs of the Convention. It considers its future work and that of the programmes and prepares a biannual workplan for consideration by the Executive Body of the Convention. Important results are brought to the attention of the Executive Body; they are also published in the scientific literature and disseminated to the public through the publication of reports, UNECE press releases and other means. The Working Group also publishes substantive reports summarizing and assessing the most important results of the activities of the international programmes.

The Working Group has an elected Bureau which is responsible for the detailed planning, coordination and reporting of the activities in the workplan. The Bureau comprises a chair and five vice-chairs. 


The Revised Long-Term Strategy of the Effects-Oriented Activities was adopted by the Executive Body in 2012 to better serve the work under the Convention, following the adoption of the Long-term strategy for the Convention and the Action Plan for its implementation.

The following priorities have been identified as of particular importance in the scientific work and in the development of methods and tools for the years 2010-2020:

(a) Provision of quantitative policy-relevant information on monitored and modelled air pollution effects;

(b) Derivation of exposure-response functions for chemical and biological effects of air pollutants, inter alia for effects of nutrient nitrogen, ozone and acidifying pollutants and ecosystems’ functioning and biodiversity, in combination with other stresses such as land management and climate change; 

(c) Gathering information on policy-relevant user friendly indicators to evaluate pollution effects on the environment and health; 

(d) Monitoring and assessment of effects on the environment and health as well as their trends; 

(e) Investigate the relevance of short lived climate forcers from the viewpoint of human and ecosystem health as well as detrimental effects on materials. 

(f) Further development of modelling and mapping procedures, in particular for effects of nitrogen and ozone on the environment, ozone and particulate matter on health, multi pollutant effects on environment and materials, and of dynamic processes of damage and recovery due to eutrophication, acidification and heavy metal accumulation, including biological effects; 

(g) Further studies of the uncertainties, robustness and validation of models, as well as data assumptions and uncertainties; 

(h) Gathering information on possible risks from POPs and heavy metals not regulated in global agreements; 

(i) Evaluation of environmental benefits of air pollution control policies, as well as contribution to economic assessment of damages.