Use of Field Data to Support European Water Framework Directive Quality Standards for Dissolved Metals

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• 作者：Mark Crane ; Kevin W. H. Kwok ; Claire Wells ; Paul Whitehouse ; Gilbert C. S. Lui
• 刊名：Environmental Science & Technology
• 出版年：2007
• 出版时间：July 15, 2007
• 年：2007
• 卷：41
• 期：14
• 页码：5014 - 5021
• 全文大小：286K
• 年卷期：v.41,no.14(July 15, 2007)
• ISSN：1520-5851

文摘

Quality standards (QS) for dissolved metals in freshwatershave been proposed under the European Water FrameworkDirective (WFD) and are based mainly upon laboratoryecotoxicity data. Uncertainties remain about laboratory-to-field extrapolation to establish QS that are neither over-nor underprotective. Freshwater benthic macroinvertebratesare a group of organisms of known sensitivity to heavymetals. We analyzed a dataset from England and Wales ofdissolved metal concentrations (cadmium, chromium,copper, iron, nickel, lead, and zinc) and associated benthicinvertebrate community metrics, using piecewise regression,quantile regression, and information on metal concentrations consistent with good quality status. Analysis of thesefield data suggests that dissolved metal QS proposedunder the WFD are similar to metal concentrations in riversassociated with unimpaired benthic invertebrate assemblages in England and Wales. The only exceptions tothis are QS for iron and zinc, where use of relativelylarge assessment factors leads to standards that aresubstantially below concentrations associated with impairedinvertebrate assemblages in the field.