title: Characterizing sediment acid volatile sulfide concentrations in European streams.
abstract: Sediment acid volatile sulfide (AVS) concentrations were measured in wadeable streams of a wide variety of ecoregions of western Europe (84 sites in 10 countries and nine ecoregions) to better understand spatial distribution and ecoregion relationships. Acid volatile sulfide has been shown to be a major factor controlling the bioavailability and toxicity of many common trace metals, such as Cd, Cu, Ni, Pb, and Zn. Sediment characteristics varied widely. The ratio of the sum of the simultaneously extracted metals (SEM) to AVS ranged from 0.03 to 486.59. The sigmaSEM-AVS ranged from -40.02 to 17.71 micromol/g. On a regional scale, sediment characteristics such as dominant parent soil material showed significant trends in AVS distribution and variation by ecoregion. Total Fe and Mn were correlated weakly with SEM concentrations. Three AVS model approaches (i.e., the SEM:AVS ratio, SEM-AVS difference, and carbon normalization) were compared at threshold exceedance levels of SEM/AVS > 9, SEM-AVS > 2, and SEM-AVS/foc > 150 micromol/g organic carbon (OC). Only 4.76% of the sediments exceeded all three AVS thresholds; 22.6% of the sediments exceeded two models; and 13% of the sediments exceeded one model only. Using the SEM:AVS, SEM-AVS, and fraction of organic carbon models, and including site-specific data and regional soil characteristics, ecoregions 1 (Portugal), 3 (Italy), 4 (Switzerland), and 9 (Belgium/Germany) had the highest potential metals toxicity; ecoregions 13 and 8 (Belgium/France) showed the lowest potential toxicity. However, because AVS can vary widely spatially and temporally, these data should not be considered as representative of the sampled ecoregions. The general relationship between AVS levels and sediment characteristics provides some predictive capability for wadeable streams in the European ecoregions.
authors.affiliation: Institute for Environmental Quality, Wright State University, Dayton, Ohio 45435, USA. allen.burton@wright.edu
authors.forename: G Allen
authors.initials: GA
authors.lastname: Burton
authors.forename: Andrew
authors.initials: A
authors.lastname: Green
authors.forename: Renato
authors.initials: R
authors.lastname: Baudo
authors.forename: Valery
authors.initials: V
authors.lastname: Forbes
authors.forename: Lien T H
authors.initials: LT
authors.lastname: Nguyen
authors.forename: Colin R
authors.initials: CR
authors.lastname: Janssen
authors.forename: Jussi
authors.initials: J
authors.lastname: Kukkonen
authors.forename: Matti
authors.initials: M
authors.lastname: Leppanen
authors.forename: Lorraine
authors.initials: L
authors.lastname: Maltby
authors.forename: Amadeu
authors.initials: A
authors.lastname: Soares
authors.forename: Katherine
authors.initials: K
authors.lastname: Kapo
authors.forename: Preston
authors.initials: P
authors.lastname: Smith
authors.forename: John
authors.initials: J
authors.lastname: Dunning
mesh_terms: D005060:Europe; D005618:Fresh Water; D019015:Geologic Sediments / Q000737:chemistry*; D013440:Sulfides / Q000032:analysis*; D014835:Volatilization
chemical_list: D013440:Sulfides