Acute exposition to Roundup Transorb® induces systemic oxidative stress and alterations in the expression of newly sequenced genes in silverside fish (Odontesthes humensis)

Environmental Science and Pollution Research - Roundup Transorb® (RDT) is a glyphosate-based herbicide commonly used in agricultural practices worldwide. This herbicide exerts negative effects...     

Voltammetric analysis of metallothioneins and copper (II) in fish for water biomonitoring studies

An major research area in environmental chemistry is the development of methods for the analysis of biomarkers. Metallothioneins are used as biomarkers in studies of heavy metals exposure in water, because metallothioneins are synthesized and accumulated when organisms are exposed to toxic concentrations of pollutants. In this work, simple and sensitive voltammetric methods were developed for metallothionein and copper (II) determinations in fish liver Lepomis gibbosus. Both analytical methodologies were optimized and applied to samples extracted from individuals previously submitted to sub-lethal toxicological trials with copper sulphate (CuSO₄) and cadmium chloride (CdCl₂). The obtained results showed that both methods are very precise, sensitive, and involve simple sample preparation processes. Moreover, metallothioneins showed better correlation with the toxic exposure than Cu²⁺. To the best of our knowledge, this is the first time that hepatic metallothioneins and Cu²⁺ contents are voltammetrically determined in order to be compared in their function as heavy metal biological indicators.     

Female ornamentation and territorial conflicts in collared flycatchers (Ficedula albicollis)

Female ornaments in species with conventional sex roles often indicate individual quality, but the evolutionary forces maintaining them are less clear. Sexual competition for breeding opportunities may represent an important role for female signals, especially in polygynous species, but there is little experimental evidence for this. The wing patch size (WPS) of female collared flycatchers indicates age and body condition and predicts social mating patterns. We challenged nest-building females with decoy females of varying WPS and found that the aggressive response of residents increased with decoy WPS, suggesting a role for this female ornament in territorial competition. Our results explain why female WPS predicts territorial distances when mated to a polygynous male and indicate that the role of WPS in female competitive interactions is similar to that in males of the same population.     

A novel approach to the sequential extraction of plutonium from oxic and anoxic sediment using sodium citrate to inhibit post-extraction resorption

Sequential extraction has been used extensively to study the solid partitioning of radionuclides in soils and sediments. A difficulty with sequential extraction is that radionuclides released by a particular extractant can be resorbed and artificially redistributed amongst the remaining solid phases. Here, we describe experiments (on selected model phase and natural materials), which were designed to determine whether the inclusion of a chelating agent (sodium citrate) in an established sequential extraction protocol (a) inhibits post-extraction resorption of plutonium, (b) increases non-targeted dissolution of sediment phases, and (c) gives rise to unwanted ligand competition for plutonium. The results clearly demonstrate the capacity of citrate to inhibit the resorption of plutonium from the various extractants, and confirm that there is no discernible increase in non-targeted phase dissolution, but indicate significant ligand competition with the carbonate phase. The merits of using citrate are discussed and an optimised sequential extraction protocol that includes citrate is proposed. Finally, the protocol is applied to oxic and anoxic sediments sampled in the NE Irish Sea and the Roads of Cherbourg, and it is shown that the bulk of the plutonium on these sediments is associated with the more labile geochemical fractions.     

Encapsulation of Nerol Oil in Polycaprolactone Polymer and Stability Evaluation

Journal of Polymers and the Environment - The objective of this study was to obtain and characterize Nerol essential oil encapsulated in PCL. The miniemulsion and solvent evaporation method was...     

Influence of a Catalyst in Obtaining a Post-consumer Pet-Based Alkyd Resin that Meets Circular Economy Principles

Journal of Polymers and the Environment - The paper studied the influence of a catalyst, comparing it with its traditional counterparts, in the process of obtaining a polyethylene terephthalate...     

Environmental performance review and cost analysis of MSW landfilling by baling-wrapping technology versus conventional system

This paper first reviews the chemical, physical and biological processes, and the environmental performance of MSW compacted and plastic-wrapped into air-tight bales with low-density polyethylene (LDPE). The baling-wrapping process halts the short and half-term biological activity and consequently the emission of gases and leachates. It also facilitates the handling of the refuse, and considerably reduces the main environmental impacts of a landfill. The main technologies available for baling-wrapping MSW are also presented. Furthermore, a cost analysis comparing a conventional landfill (CL) without baling system versus two landfills using different baling-wrapping technologies (rectangular and cylindrical bales) is carried out. The results are presented comparatively under the conditions of construction, operation and maintenance and postclosure, as required by European Directive 1999/31. A landfill using rectangular plastic-wrapped bales (LRPB) represents an economically competitive option compared to a CL. The increased capacity of the waste disposal zone when using rectangular bales due to the high density of the bales compensates for the increased operating and maintenance (O&M) costs of the method. Landfills using cylindrical plastic-wrapped bales (LCPB's) do not fare so well, mainly because the density within the bales is lower, the cylindrical geometry of the bales does not allow such an efficient use of the space within the landfill, and the processing capacity of the machinery is lower. From the cost model, the resulting unit costs per tonne in a LRPB, a LCPB and a CL for 100,000 t/year of waste, an operation time of 15 years and a landfill depth (H) of 20 m, are 31.52, 43.36 and 31.83 /t, respectively.     

Actinide analysis of a depleted uranium penetrator from a 1999 target site in southern Serbia

Following the detection of 236U in depleted uranium (DU) ammunition used during the Balkans conflict in the 1990s, concern has been expressed about the possibility that other nuclides from the nuclear fuel cycle and, in particular, transuranium nuclides, might be present in this type of ammunition. In this paper, we report the results of uranium and plutonium analyses carried out on a depleted uranium penetrator recovered from a target site in southern Serbia. Our data show the depleted nature of the uranium and confirm the presence of trace amounts of plutonium in the penetrator. The activity concentration of (239+240)PU, at 45.4+/-0.7 Bq kg(-1), is the highest reported to date for any penetrator recovered from the Balkans. This concentration, however, is comparable to that expected to be present naturally in uranium ores and, from a radiological perspective, would only give rise to a very small increase in dose to exposed persons compared to that from the DU itself.