Direct toxicity assessment

Campbell, C. Warren, A. Cameron, C. Hope, S. Direct toxicity assessment of two soils amended with sewage sludge contaminated with heavy metals using protozoan Colpoda steinii) bioassay. Chemosphere 1997, 34, 501-514. 

DTA Direct toxicity assessment. Biological effect test for whole mixture samples. 

Cairns J., McCormick P.V. and Niederlehner B.R., 1992. Hydrobiologia, 237, 131-45. Environment Agency (UK), 2006. Monitoring Certification Scheme (MCERTS) Performance Standard for Laboratories Undertaking Direct Toxicity Assessment of Effluents. 

Tinsley, D., Johnson, I., Boumphrey, B., Forow, D. and Wharfe, J. (1996) The use of direct toxicity assessment to control discharges to the aquatic environment in the United Kingdom. In Toxic Impacts of Wastes on the Aquatic Environment, Tapp, J.F., Hunt, S.M. and Wharfe, J.R. (eds), pp. 36-43. Royal Society of Chemistry, London. 

Effluent control as part of a Direct Toxicity Assessment (DTA) approach (UKWIR, 2001), based on the recommendations of a DTA Demonstration Programme completed in 2000. Toxicity-based conditions may be implemented as part of Integrated Pollution Prevention and Control (IPPC) authorisations or to control emissions under the Water Resources Act. 

Such an approach was trialled in the late 1990s as part of an initiative by the Environment Agency in the UK. It led to proposals for a quality control scheme for use within the Agency s Direct Toxicity Assessment programme for effluent assessment and control. The trial entailed an interlaboratory ring-test of four test methods using two toxicants (3,4-dichloroaniline and zinc sulphate) from which accuracy and precision criteria were estimated, as described below. 

Butler, R., Johnson, I., Horn, K. and Paul, M. (1992) Discharge Control by Direct Toxicity Assessment (DTA) Evaluation of a Protocol by Case Studies, WRc Interim Report to the NRA, R D 049/9/W. National Rivers Authority, Bristol. 

UKWIR (2001) UK Direct Toxicity Assessment Demonstration Programme, Technical Guidance Report No. 00/TX/02/07. UW Water Industry Research, London. 

Some useful sources of information on the UK Direct Toxicity Assessment (DTA) demonstration programme ... 

UKWIR (2000) Technical Guidance for the Implementation of Direct Toxicity Assessment (DTA) for Effluent Control Addressing Water Quality Problems in Catchments where Acute Toxicity is an Issue. Report TX02B 217. 

Dalzell, D.J.B.. Alte, S., Aspichueta, E., de la Sola, A., Etxebarria, J., Gutierrez, M. et al. (2002) A comparison of five rapid direct toxicity assessment methods to determine toxicity of pollutants to activated sludge, Chemosphere, 47, pp. 535-545. 

Direct toxicity assessment (DTA) can also be used to account for the combined effects of contaminants. Measurements taken from biological and ecotoxicological tests are more directly related to ecological risk, because they measure the biological effects from a mixture of contaminants and, in doing so, provide an implicit indication of the bioavailability of the contaminants. Some tests can be simple and cost-effective in comparison to screening for multiple chemical... 

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