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.

Impacts of Plastic-Made Packaging on Marine Key Species: Effects Following Water Acidification and Ecological Implications

This study evaluates the impacts of 16 different leachates of plastic-made packaging on marine species of different trophic levels (bacteria, algae, echinoderms). Standard ecotoxicological endpoints (inhibition of bioluminescence, inhibition of growth, embryo-toxicity) and alterations of ecologically significant parameters (i.e., echinoderms’ body-size) were measured following exposure under different pH water conditions: marine standard (pH 8.1) and two increasingly acidic conditions (pH 7.8 and 7.5) in order to evaluate possible variations induced by ocean acidification. The results obtained in this study evidence that the tested doses are not able to significantly affect bacteria (Vibrio fischeri) and algae (Phaeodactylum tricornutum). On the contrary, Paracentrotus lividus larvae were significantly affected by several packaging types (13 out of 16) with meaningless differences between pH conditions.

Preliminary ecotoxicity assessment of selected flavour and fragrance compounds using Microtox assay

The bioluminescence inhibition bioassay using marine bacteria Vibrio fischeri is widely used as a tool to assess the toxicity of chemical compounds, because of the many benefits comprising cost and time effectiveness, rapidness, sensitivity, and ease of operation. In addition, the test is used for various types of organic and inorganic compounds. Due to the insolubility of organic compounds in water, a suitable solubilizer should be applied. The ecotoxicity of the solvent should be negligible in relation to marine bacteria. On account of superior human activities the synthesis of new chemical substances is inextricably linked to the emergence of chemical compounds that are a potential threat on environment. A Microtox system utilizing the 81.9% Basic Test with 14 dilutions was applied to pre-evaluate the ecotoxicity of β-cyclocitral oxime, citronellal oxime and perillaldehyde oxime. Substances solutions with an initial concentration of 0.036% in DMSO were prepared. The preliminary results show that the studied scent compounds are characterized by quite high toxicity. In order to confirm the received ecotoxicity values, it is necessary to carry out additional surveys using another range of concentrations and biotests on organisms at each trophic level.

Assessing Ecotoxicity of Size-fractionated Airborne Particulate Matter

Particulate matter (PM) is grouped as coarse, fine, and ultrafine particles (UFPs) with aerodynamic diameters of 2.5 to 10 μm (PM10), <2.5 μm (PM2.5), and <0.1 μm (PM0.1), respectively. The course and fine fractions have been well characterised from numerous aspects, including potential environmental hazard. However, more and more studies are targeted to the UFP fraction, as they bind relatively higher concentrations of potentially toxic materials and they might penetrate through cell biological barriers, posing higher risk to the biota. In our study, ecotoxic potential of size-fractionated urban aerosol was evaluated, using the kinetic version of the Vibrio fischeri bioluminescence inhibition bioassay. The kinetic protocol makes it possible to avoid false ecotoxicity readings which might appear in case of coloured and/or turbid samples. Our results showed that all PM fractions elucidated significant toxic response, highest toxicity was experienced in the range of 0.25/0.5μm and 0.5/1 μm (with the EC50s of 7.07 and 7.8%). Ecotoxicity in general followed the typical pattern of number size distributions of submicron particles experienced in Europe.

General baseline toxicity QSAR for nonpolar, polar and ionisable chemicals and their mixtures in the bioluminescence inhibition assay with Aliivibrio fischeri

A general QSAR model for the Microtox assay with the ionisation-corrected liposome–water distribution ratio is applicable to diverse chemicals including acids and bases.