title: Addressing geographic variability in the comparative toxicity potential of copper and nickel in soils.
abstract: Comparative toxicity potentials (CTP), in life cycle impact assessment also known as characterization factors (CF), of copper (Cu) and nickel (Ni) were calculated for a global set of 760 soils. An accessibility factor (ACF) that takes into account the role of the reactive, solid-phase metal pool in the soil was introduced into the definition of CTP. Geographic differences in fate, accessibility, bioavailability, and terrestrial toxicity were assessed by combining the USEtox characterization model, empirical regression models, and terrestrial biotic ligand models. The median CTPs for Cu and Ni with 95% geographic variability intervals are 1.4 × 10(3) (1.7 × 10(2) to 2.0 × 10(4)) and 1.7 × 10(3) (2.1 × 10(2) to 1.1 × 10(4)) m(3)/kg · day, respectively. The geographic variability of 3.5 orders of magnitude in the CTP of Cu is mainly associated with the variability in soil organic carbon and pH. They largely influence the fate and bioavailability of Cu in soils. In contrast, the geographic variability of 3 orders of magnitude in the CTP of Ni can mainly be explained by differences in pore water concentration of magnesium (Mg(2+)). Mg(2+) competes with Ni(2+) for binding to biotic ligands, influencing the toxicity. Our findings stress the importance of dealing with geographic variability in the calculation of CTPs for terrestrial ecotoxicity of metals.
authors: Division for Quantitative Sustainability Assessment, Department of Management Engineering, Technical University of Denmark, Nils Koppels Alle, Building 426D, DK-2800 Kgs Lyngby, Denmark. miow@dtu.dk
authors: Mikołaj
authors: M
authors: Owsianiak
authors: Ralph K
authors: RK
authors: Rosenbaum
authors: Mark A J
authors: MA
authors: Huijbregts
authors: Michael Z
authors: MZ
authors: Hauschild
mesh_terms: D001682:Biological Availability; D003300:Copper / Q000633:toxicity*; D005843:Geography; D016014:Linear Models; D009532:Nickel / Q000633:toxicity*; D012987:Soil / Q000737:chemistry*; D012989:Soil Pollutants / Q000633:toxicity*
chemical_list: D012987:Soil; D012989:Soil Pollutants; D003300:Copper; D009532:Nickel