NORMAN

Workshop on Mixtures and Metabolites of Chemicals of Emerging Concern
18-19 November 2009 - Amsterdam, The Netherlands

Releases of chemicals in the environment often cause the formation of transformation products which may be more toxic than the parent compound. This possibility of increased toxicity over time has been afforded insufficient attention in chemical regulation. There is, moreover, limited awareness of the analytical implications of this phenomenon. With this in mind, a workshop on mixtures and metabolites of chemicals was organised by RIVM (National Institute for Public Health and the Environment) and IVM (Institute for Environmental Studies – VU University [The Netherlands]) and took place in Amsterdam on 18–19 November 2009.

About 70 participants attended the workshop, with 16 presentations (available as pdf files - see below)

and 11 posters. The conclusions of this two-day workshop are presented in a specific report. However, it was already clear from the discussion that the co-occurrence of chemicals in the environment plays an important role in the overall environmental impact of chemicals.

The ecotoxicological assessment of mixtures is complex and there are still many knowledge gaps. But checking compliance with environmental quality standards alone is obviously not sufficient: a number of modelling tools for prediction of mixtures effects exist already and they need to be integrated in future routine risk assessment protocols.

The second day was focused on the tools for identification and analysis of the metabolites and transformation products of chemicals of emerging concern. Here again, the main tools available (in silico methods, analytical techniques, bioreactors, field studies) to study the chemicals’ transformation products were presented.

But knowledge gaps still exist in the analysis of transformation products, fate and transport, and toxicity of these compounds. Moreover, most of the current studies addressed two main classes of compounds: pesticides and pharmaceuticals. Is this the tip of the iceberg? How many transformation products should also be covered?

PROGRAM

WORKSHOP REPORT (482 kB).

WORKSHOP PROGRAM AND PRESENTATIONS

Wednesday November 18, 2009