1. Environmental Exposure Assessment
OECD has been working on environmental exposure assessment of chemicals with special focus on the following four areas. These activities are supervised by the Task Force on Exposure Assessment (formally the Task Force on Environment Exposure Assessment), composed of experts nominated by OECD member countries and observer organisations. This Task Force was established in 1995, following a recommendation from the OECD Workshop on Environmental Hazard/Risk Assessment in 1994.
(1) Release estimation
To improve the estimation of releases of chemicals to the environment, OECD is developing emission scenario documents that describe the conditions and parameters for release estimation in specific industry and use categories.
Estimation of releases of chemicals to the environment related to the use of products and articles is becoming increasingly important in risk assessment of chemicals of concern. Although these releases are covered in some of the emission scenario documents, further activities to address this issue is under consideration. This work is undertaken in close co-operation with the PRTR Programme.
(2) Exposure models
Many kinds of computer models are used in environmental exposure assessment. Harmonised approaches for the use of exposure models were discussed in the Workshop on the Application of Simple Models for Environmental Exposure Assessment in 1991.
More recent activities on exposure models include the development of a database of exposure models, and development of a guidance document on the use of multimedia models in the assessment of overall persistence (POV) and long-range transport potential (LRTP) as well as an actual OECD POV and LRTP Screening Tool. These guidance document and the tool were developed as a follow-up to an OECD/UNEP Workshop in October 2001.
(3) Use of monitoring data
The Workshop on Improving the Use of Monitoring Data in the Exposure Assessment of Industrial Chemicals (Berlin, May 1998) delivered a number of recommendations on improving the availability of monitoring data, better design of monitoring programmes, and enhanced dialogue between monitoring and risk assessment communities. Specific projects to follow up on these recommendations are currently on-going.
(4) Reporting of exposure information
OECD published a Guidance Document on Reporting Summary Information on Environmental Occupational Exposure in December 2003. This includes a set of formats for reporting information including monitoring and modelling studies.
2. New Work on Human Health Exposure Assessment
In 2008, OECD member countries agreed to extend the scope of the work to human health exposure assessment. The following topics were identified by the Task Force on Exposure Assessment as initial activites of interests on human exposure assessment, and several follow-up projects have started.
- Identification of information on use patterns.
- Identification of sources of exposure data, mainly for estimating exposure to consumers and/or the general public.
- Identification of exposure models and estimation approaches/methods, mainly for estimating exposure to consumers and/or the general public.
- Studies, databases or guidance regarding exposure to plasticizers.