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PARENT SESSION

TA8 Field-Based Effects Measures
A105 & A106
8:00 AM - 12:00 PM, Tuesday

() In situ bioassays: their role in the regulatory assessment framework.

Wharfe, James1, 1 Environment Agency, National Centre for Ecotoxicology & Hazardous Substances, Wallingford, Oxon., UK

ABSTRACT- In Europe, the risk assessment procedures under the existing substances regulations are considered too slow and have failed to translate into effective risk management action. New speedier streamlined procedures for the Registration, Evaluation and Assessment of Chemicals (REACH) are planned. Separate legislation concerning the control of chemicals released to the environment is large and complex. There is a hierarchy from international protocols and agreements to national and regional legislation for the implementation of community directives in Europe. As a result there are many different priority lists of substances with little attempt at integration and with unclear criteria for selection or de-selection. Risk assessments of priority substances often lack field verification. More importantly these separate pieces of legislation focus on individual substances or groups of substances taking no account of additive or synergistic effect in complex mixtures. More recently the introduction of outcome-based measures in the Birds and Habitats Directive and in the Water Framework Directive provide an opportunity for biological effect-based measures to be recognised. Bioassays are now used in many countries (REF) to help assess the toxicity of complex mixture released from point source discharges and a wide range of biomarker responses have been reported in the literature, primarily against contaminant induced effects under laboratory controlled conditions or against pollutant gradients in the field. Although these approaches have helped understand and prioritise some screening at the first tier of the risk assessment more intensive and traditional toxicological methods and end-points are used at the higher tiers. Often the question of relevance is inadequately answered and improved methodologies and multiple lines of evidence are required. To improve the risk assessment process it is necessary to first identify the fit for purpose role of in-situ methods together with the required level of quality assurance needed to make decisions. To do this a number of selection criteria need to be considered to help the development and application of new methodologies.

Key words: field-based effects, in situ bioassay


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