Assessing the Concentrations of Polar Organic Microcontaminants from Point Sources in the Aquatic Environment: Measure or Model?

Johnson, Andrew C.; Ternes, Thomas; Williams, Richard J.; Sumpter, John P.. 2008 Assessing the Concentrations of Polar Organic Microcontaminants from Point Sources in the Aquatic Environment: Measure or Model? Environmental Science & Technology, 42 (15). 5390-5399.

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To carry out meaningful ecotoxicity studies on novel polar organic microcontaminants it is essential to know what concentrations wildlife may be exposed to. Traditionally these values were obtained by analytical chemistry, but in recent years GIS water quality models have been developed which may offer a quick and reliable way of getting the same information. Thus, two ways of obtaining basically the same information now exist, and an issue therefore arises as to which method is the most appropriate to use in which situation? To address this issue we have critically reviewed and compared measuring and modelling approaches for the determination of sewage effluent and river water concentrations of organic microcontaminants. Where model predictions and chemical measurements can be directly compared in sewage effluents, receiving waters and across catchments, reported model mean values have all been within one order of magnitude of the measured values, with typically no more than a 3 or 4-fold difference. Inter-laboratory chemical analysis of some organic microcontaminants in effluents in the challenging ng/L range have provided results which have varied from one another by a similar margin. No such comparison has been carried out yet for GIS water quality models to determine variation in predicted concentrations. As the level of ecotoxicological effects of many chemicals is often considerably higher than the reported measured or modelled values, such errors that might occur will often be of no consequence. But due to their extraordinary potency, much more accuracy is required with some natural and synthetic hormones. Significantly, modelling is no more complex to conduct when dealing with contaminants at ng/L compared with mg/L concentrations, but the same cannot be said for chemical analysis. A combination of modelling and measuring techniques will give the greatest confidence in risk assessment.

Item Type: Publication - Article
Digital Object Identifier (DOI):
Programmes: CEH Programmes pre-2009 publications > Biogeochemistry > SE01B Sustainable Monitoring, Risk Assessment and Management of Chemicals > SE01.4 Monitoring and predicting the distribution of chemicals in terrestrial and freshwater ecosystems
CEH Programmes pre-2009 publications > Water > WA03 Developing strategic data and knowledge at a catchment scale to enable the wiser management of the water environment > WA03.3 Catchment scale modelling and assessment
UKCEH and CEH Sections/Science Areas: Acreman
ISSN: 0013-936X
Additional Keywords: Modelling, measurements, organic microcontaminants, estrogens
NORA Subject Terms: Management
Ecology and Environment
Related URLs:
Date made live: 23 Sep 2008 12:03 +0 (UTC)

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