Biological assessment methods integration with chemical

Biological sui veys shall be fuUy integrated with toxicity and chemical-specific assessment methods in state water-quahty programs. ... [Pg.2161]

Ecotoxicity can only be measured by the application of biological methods, whereas chemical analysis determines concentrations of defined chemicals that may be used to deduce toxic effects. All concentration levels such as screening values, guideline values, threshold concentrations, benchmark concentrations and trigger values used for the assessment of contaminated media (water, soil, sediments, etc.) should ideally be derived from the observation of biological effects. Comparing pollutant concentrations with these usually conservative standard values is a common practice in the preliminary assessment of contaminated sites. The integration of further information, such as ecotoxicity data from the site, can improve the risk assessment process and enable a more reliable prediction of environmental threats. [Pg.229]