A new approach to testing potential leaching toxicity of fouling release coatings (FRCs).

Fouling release coatings (FRCs) are today the main environment-friendly alternative to traditional self-polishing coatings, that continuously release biocides and/or heavy metals into water. FRCs are available on the market as environmentally friendly AF paints and most of them do not contain bioactive agents, however no complete and reliable assessment of their environmental impact has yet been carried out. Only few literature data proving their AF efficacy combined with a demonstrated lack of toxicological effects are available. Ecotoxicological bioassays are commonly used to predict the potential environmental impact of traditional AF paints. Standardized methodologies to obtain leaching products from biocide-based paints are available, while few studies propose experimental methods to assess the potential effects of biocide-free FRCs leachates on non-target organisms. The aim of this work is to propose an experimental protocol to obtain leaching products from biocide-free FRCs in order to evaluate the potential release of substances having toxic effects, by means of an ecotoxicological bioassay. Two ecotoxicological end-points with different sensitivity levels were considered (multi-end-point approach). Five silicone-based commercial coatings were used: their leaching products were collected after different immersion times following the developed experimental method and then two ecotoxicological end-points were evaluated on II stage nauplii of the crustacean Amphibalanus amphitrite as model organism. Moreover, chemical analyses were performed on leachates collected after each immersion time, focusing on the presence of metals in leaching products. From the results obtained from the bioassay, even if not indicative of the real environmental impact of FRCs, a release of toxic substances was observed from tested coatings during early immersion stages, likely to affect the exposed model organism. The potential leaching toxicity of the five tested products was compared. No clear correspondence could be identified between the concentrations of metals detected in leachates and the obtained ecotoxicological data, thus suggesting that other active components might be released by FRCs responsible for the toxic effects pointed out on A. amphitrite larvae.

Risk assessment of selected priority pollutants coming from boating activities.

In this work, we evaluated the risk posed to aquatic organisms in the coastal waters of Albania and Apulia (Italy) by two priority pollutants (PPs), Irgarol 1051 and Diuron, used as biocides in antifouling paints on boat hulls. With this aim, we carried out an extensive 3-year monitoring in ports and marinas along the coasts of both countries, which showed a widespread occurrence of both PPs, with Irgarol 1051 concentrations usually being lower than the Diuron ones. The measured concentrations were compared with regulatory Environmental Quality Standards (EQS) (Directive 2008/105/EC) and used to perform a probabilistic Ecological Risk Assessment (ERA), for a thorough evaluation of the potential adverse effects upon marine ecosystem. Irgarol 1051 amounts above the Annual Average Concentration (AA-EQS, 2.5 ng/L) were often detected in Apulia and, less frequently, in Albania. Moreover, in Apulia, sometimes the Maximum Allowable Concentrations (MAC-EQS, 16 ng/L) was exceeded. In Apulia, where levels exceeded MAC/AA-EQS, ERA found not negligible probabilities of exceeding the toxicity level (6-18 %). A less critical situation was observed for Diuron whose levels were always below the MAC-EQS (1800 ng/L) in both countries and, in Albania, also below the AA-EQS (200 ng/L). On the other hand, in Apulia, this limit was exceeded in some locations. Correspondingly, ERA determined a not negligible risk in these sites (probability of exceedance 4-7 %).

First evaluation of the threat posed by antifouling biocides in the Southern Adriatic Sea.

The CARISMA project (characterization and ecological risk analysis of antifouling biocides in the Southern Adriatic Sea) aims to appraise the quality of the Southern Adriatic Sea between Italy (Apulia region) and Albania and, in particular, the impact due to the use of biocidal antifouling coatings. Under this project, a preliminary survey at the main hot spots of contamination (e.g. ports and marinas) was conducted at the end of the nautical season in 2012. Chemical seawater analyses were complemented with ecotoxicological assays and the results were analyzed by principal component analysis (PCA). As expected, PCA splits the Albanian and Italian ports, according to the different degrees of contamination indicated for the two countries by the experimental data, highlighting the most critical situation in one port of Apulia. In addition, in order to assess the potential adverse ecological effects posed by antifouling agents (i.e. tributyltin (TBT)-irgarol-diuron) on non-target marine organisms, hazard quotients (HQ) were calculated. The results showed a low risk posed by irgarol and diuron whereas the probability of adverse effects was high in the case of TBT.

Propolis specimens from different locations of central Italy: chemical profiling and gas chromatography-mass spectrometry (GC-MS) quantitative analysis of the allergenic esters benzyl cinnamate and benzyl salicylate.

Propolis is a beehive product popular in natural medicine thanks to its noteworthy properties. Propolis is non-toxic but is responsible for allergic reactions in sensitive individuals. In this paper, we propose a new gas chromatography-mass spectrometry (GC-MS) analytical methodology for the quantitative analysis of two allergenic esters in propolis specimens, benzyl salicylate and benzyl cinnamate, and test it on specimens from different locations of central Italy. We also present the results obtained in the chemical characterization of the same specimens. The characterization showed that the resin fractions of all of the specimens are of poplar origin.

Organotins in the sediments of the Zuari estuary, west coast of India.

Industrial use of organotins such as butyltins and phenyltins has increased several folds during the last two decades. Butyltins and phenyltins are synthetic, multipurpose chemicals, which have been extensively used in marine antifouling paints. They have been known to be extremely poisonous to mollusc fishery resources (oysters, clams, etc.). Contamination of Zuari estuary sediments was assessed by quantitative determination of butyltins and phenyltins by using GC-MS using the electron ionization mode. Butyltins predominated in the whole area over phenyltins. Butyltins contributed about 70-90% of the organotins in general. The concentration of butyltins in sediments ranged from 20 to 7621 ng Sn/g. The concentration of phenyltins in sediments ranged from 0 to 46 ng Sn/g. Degradation indices for butyltins and phenyltins were calculated. The Butyltin degradation index (BDI) for the Zuari sediments ranged from 0 to 2.7 indicating a lot of fresh input of butyltins in the estuary and a lower degradation rate. The phenyltin degradation index (PhDI) ranged from 1 to 10 implying that different processes were prevalent at different stations. The observed organotin levels in the Zuari estuary indicate some highly localized areas of contamination which are severe enough to cause harmful effects on marine flora and fauna. Therefore, there is a need to regulate the use of butyltins and phenyltins as biocides in marine antifouling paints.

Reuse of a treated red mud bauxite waste: studies on environmental compatibility.

Red mud is the major solid waste produced in the process of alumina extraction from bauxite (Bayer process). Environmental "compatibility" of a treated red mud was studied in order to evaluate its possible recycling in environmental compartments. The leaching test requested by the Italian law on treated solid waste to be "re-introduced in the environment" was performed on this material. Moreover, in order to better evaluate the environmental compatibility, three different types of eco-toxicological tests were applied (Microtox test, ASTM microalgae toxicity test and sea urchin embryo toxicity test). These "chemical" and eco-toxicological tests gave encouraging results. The possibility to use this material for treating contaminated waters and soils was evaluated, again with particular attention to the Italian regulatory system, through experiments on the treated red mud metal trapping ability and on the subsequent release of trapped metals, at low pH conditions. The treated red mud showed a general high metal trapping capacity and the release at low pH was generally low.