Application of a Multidisciplinary Weight of Evidence Approach as a Tool for Monitoring the Ecological Risk of Dredging Activities

The use of multidisciplinary investigations for the evaluation of aquatic ecosystems status is recommended by the European Directives, but it is still a challenging practice. In this study, we apply a quantitative weight of evidence (WOE) approach (Sediqualsoft) for the integration of extensive data obtained from different typologies of investigations, obtained over a 4-year monitoring study of dredging activities in the harbor of Leghorn (Italy). During different phases of such operations, selected sites have been characterized in terms of levels of trace metals and polycyclic aromatic hydrocarbons in sediments, bioaccumulation of contaminants, and a wide battery of biomarkers in transplanted mussels, ecotoxicological effects of sediments through a battery of bioassays (algal growth inhibition, bioluminescence inhibition, and embryotoxicity tests), and the status of benthic communities. Each typology of data, line of evidence (LOE), has been initially elaborated through dedicated logical flowcharts and algorithms providing specific hazard indices, followed by their overall integration based on different weights assigned to each LOE. This approach allowed to summarize more than 10,000 results, reaching robust conclusions on environmental impact during various phases of dredging operations. This approach was confirmed as a useful tool for monitoring the risk, supporting a “site-oriented” decision making process by providing stakeholders simple interpretation of complex data.

Environmental Footprint of Wastewater Treatment: A Step Forward in the Use of Toxicological Tools

The assessment of the actual impact of discharged wastewater on the whole ecosystem and, in turn, on human health requires the execution of bioassays. In effect, based on the chemical characterization alone, the synergistic/antagonistic effect of mixtures of pollutants is hardly estimable. The aim of this work was to evaluate the applicability of a battery of bioassays and to suggest a smart procedure for results representation. Two real wastewater treatment plants were submitted to analytical campaigns. Several baseline toxicity assays were conducted, together with tests for the determination of endocrine activity, genetic toxicity and carcinogenicity of wastewater. A “traffic light” model was adopted for an easy-to-understand visualization of the results. Although the legal prescriptions of chemical parameters are fully complied with, bioassays show that a certain biological activity still residues in the treated effluents. Moreover, influent and effluent responses are not always appreciably different. Some tests employing human cells were revealed to be only partially adequate for environmental applications. An interesting and helpful development of the present approach would consist in the estimation of biological equivalents of toxicity, as shown for the estrogenic compound 17-β-estradiol.

Analytical methodology for evaluation of the effects of different leachate treatment methods

Characterisation of the efficiency of leachate treatment methods when considering differentgroups of pollutants as phenolic compounds, PCB,s, PBDEs and phthalates is discussed.Strategies for measurements, identification and quantifications of the organic pollutants arepresented and the use of supported liquid membrane extraction (SLM) and micro porousmembrane extraction (MMLLE) in particular, where small and medium molecules areseparated from large molecules. Acute and chronic toxicity tests by biological methods andthe choice of organisms are also presented as well as the LAQUA-protocol used at the pilotplant in Kristianstad, Sweden. In acute toxicity tests of the leachate a clear accommodating onthe immobility of the Artemia larvae and increasing concentration of leachate was noted.Different species react different on different compounds and therefore on complex effluentsas landfill leachates the use of a battery of bioassays is recommended.

Synthesis and ecotoxicological impact of ferrocene-derived amino-phosphonates using a battery of bioassays

Ferrocene-derived aminophosphonates showed their various ecotoxicological impact on terrestrial higher plants, freshwater ostracods and marine bacteria.