145 research outputs found

    Influence of the salinity adjustment methods, salts and brine, on the toxicity of wastewater samples to mussels embryos

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    One of the main problems of the Whole Effluent Toxicity is related to the use of bioindicator species representative of the target environment. Most wastewater discharges are of fresh water, so their salinity has to be adjusted when they are discharged to transitional and marine coastal waters, in order to perform toxicity bioassays with reliable organisms. At the moment, there is no optimum technique to allow sample salinity to be adjusted and no specific information regarding salinity adjustment when bivalves are being considered for toxicity test performance. This paper provides information on the potential use of different methods to adjust the salinity of hotel/domestic wastewater samples with different brands of natural and synthetic Dry Salts (DS) and HyperSaline Brine (HSB) for use in the embryo larval development bioassay with the mussel Mytilus galloprovincialis. HyperSaline Brine derived from reconstructed artificial seawater proved to be more viable for wastewater salinity adjustment than DS

    Toxicity of rare earth elements: An overview on human health impact

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    Rare earth elements (REEs) are metals including the 15 lanthanides together with Yttrium and Scandium. China is the leading country in their exploitation and production (~90%). REEs are necessary for the production of several technological devices. This extended use of REEs has raised concerns about human health safety. In this review, we investigated the hazard of REEs to human health and the main gaps into the knowledge like as the need to develop further focused research activity. We categorized the research papers collected into eight main sections: environmental exposure, association of REEs with health problems, exposure to REEs due to lifestyle, REE exposure through the food chain, Gd contrast agents causing health problems, occupational REE exposure, and cytotoxicity studies of REEs. This review provided information about the exposome of REEs (the exposure of REEs to the human body), the existing research data, and the gaps that require attention and must be further investigated. More than one third of the literature about REE toxicity to human health concerns their cytotoxicity to human cell lines, while hair, blood serum and blood are the most studied matrices. The main results evidenced that REEs can enter human body via several routes, are associated with numerous diseases, can cause ROS production, DNA damage and cell death, and are more toxic to cancer cells than normal cells

    Effects of different moisture sorption curves on hygrothermal simulations of timber buildings

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    Building energy simulations are a key tool to design high performance buildings capable of facing the future challenges and to help reaching the emissions reduction targets. Currently, thermal properties of materials used in most building energy simulations are assumed to be constant and not dependent of moisture content and temperature. Heat and moisture dynamic transfer models allow to simulate building envelope performance considering thermal resistance reduction due to moisture effects. These models are generally considered more accurate than the heat transfer models and they could be used to simulate the heat transfer (increased by water vapour storage) and the moisture buffering effect on the indoor environment. For the simulation to be performed, hygrothermal material properties should be known as functions of moisture content. Nevertheless, hygrothermal material properties are rarely available and correlations from the literature have to be used. In this study, the moisture storage curves of CLT, OSB and two types of wood fibre insulation have been measured with a dynamic vapour sorption analyser. The other hygrothermal properties are estimated from values measured in previous studies or taken from the literature. The simulations of two small single room buildings in four Italian locations are performed with the software EnergyPlus, considering an ideal HVAC system, to calculate the heating and cooling needs of the building. The HAMT (heat and moisture transfer) module of EnergyPlus is used. With the results presented in this study, it is possible to evaluate how an approximated curve affects the results of a whole-building simulation in terms of wall average water content, indoor air relative humidity and heating/cooling loads

    Hygrothermal modelling of building enclosures: reference year design for moisture accumulation and condensation risk assessment

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    Interstitial condensation and water accumulation risk in building envelopes could be assessed with methods and models base d on moisture migration through porous media coupled to heat transfer. One of the difficulties in evaluating the boundary conditions for the heat and mass transfer model is the choice of an appropriate weather file. The most advanced models, described by the standard EN 15026:2007, require the hourly values of rain, wind, radiation, temperature and relative humidity to compute the water content in the porous materials. In this contribution, the method described by the standard EN ISO 15927-4:2005, typically used to design Moisture Reference Years (MRY), has been extended to the design of 34 typologies of representative weather files. The generation criteria have been base d on the assumption that the simulation results are influenced by rain deposition on the considered wall. The procedure has been followed considering 5 different wall exposures that lead to different MRY. The years of the climate of Turin (Italy) between 2002 and 2016 have been considered for the generation of the reference years. Finally, the annual mean moisture contents for two common wall types have been calculated using the obtained MRY and compared to the annual mean moisture contents obtained with the measured weather data, and the effects of the selection of the weather parameters is presented

    In situ microcosm remediation of polyaromatic hydrocarbons: influence and effectiveness of Nano-Zero Valent Iron and activated carbon

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    : Nano-zero-valent iron (nZVI) and activated carbon (AC) addition are ongoing techniques for the remediation of hydrophobic organic compound-contaminated sediment and water, but with still unexplored eco(toxico)logical implications, especially when applied in situ. In this study, we investigated AC and nZVI as remediation methods for marine contaminated sediment and water, including chemical and toxicity (Artemia franciscana survival and genotoxicity) surveys. The removal efficiency of AC and nZVI (about 99%) was similar in both sediment and seawater, while the survival of nauplii and adults was mainly impacted by nZVI than AC. At the molecular level, the nZVI-addition induced down-regulation in the expression of two stress and one developmental genes, whereas AC was able to up-regulated only one gene involved in stress response. Results suggested that the use of AC is safer than nZVI that requires further investigation and potential optimization to reduce secondary undesired effects

    Effects of commercial formulations of glyphosate on marine crustaceans and implications for risk assessment under temperature changes.

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    Abstract Glyphosate-based formulations are the most commonly used herbicides worldwide with the risk of potential contamination of aquatic bodies. The present study assessed the response of four marine crustaceans to three different brands of herbicides Roundup®Platinum, Efesto® and Taifun® MK CL.T, under two selected temperatures of 20 °C and 30 °C. The harpacticoid copepod Tigriopus fulvus, the anostracan Artemia franciscana, the amphipod Corophium insidiosum and the isopod Sphaeroma serratum were chosen as testing organisms. Effects of herbicides and temperatures were assessed by estimating lethal concentrations. The results showed that the high temperature rises the toxicity of glyphosate with an increase of mortality of all the tested species. This is an important aspect for future risk assessments of pesticides under global climate change scenarios. Efesto® resulted the most toxic brand, showing C. insidiosum the most sensitive with 96 h-LC50 values of 3.25 mg/L acid equivalent (a.e.) at 30 °C and 7.94 mg/L a.e. at 20 °C followed by T. fulvus while A. franciscana and S. serratum were the less sensitive. This study provides important information for assessing the toxic effects of three different brands of glyphosate-based herbicides on non-target marine organisms suggesting that they should be carefully managed to minimize any negative impact on marine organisms

    Toxicity Effects of Functionalized Quantum Dots, Gold and Polystyrene Nanoparticles on Target Aquatic Biological Models: A Review

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    Nano-based products are widespread in several sectors, including textiles,medical-products, cosmetics, paints and plastics. Nanosafety and safe-by-design are driving nanoparticle (NP) production and applications through NP functionalization (@NPs). Indeed, @NPs frequently present biological effects that differ fromthe parentmaterial. This paper reviews the impact of quantumdots (QDs), gold nanoparticles (AuNPs), and polystyrene-coredNPs (PSNPs), evidencing the role ofNP functionalization in toxicity definition. Key biological models were taken into consideration for NP evaluation: Saccharomyces cerevisiae, fresh- (F) and saltwater (S)microalgae (Raphidocelis subcapitata (F), Scenedesmus obliquus (F) and Chlorella spp. (F), and Phaeodactylum tricornutum (S)), Daphnia magna, and Xenopus laevis. QDs are quite widespread in technological devices, and they are known to induce genotoxicity and oxidative stress that can drastically change according to the coating employed. For example, AuNPs are frequently functionalized with antimicrobial peptides, which is shown to both increase their activity and decrease the relative environmental toxicity. P-NPs are frequently coated with NH2 for cationic and COOH for anionic surfaces, but when positively charged toxicity effects can be observed. Careful assessment of functionalized and non-functionalized NPs is compulsory to also understand their potential direct and indirect effects when the coating is removed or degraded

    Toxicity of diatom-derived polyunsaturated aldehyde mixtures on sea urchin Paracentrotus lividus development

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    Diatom-derived polyunsaturated aldehydes (PUAs), decadienal, heptadienal and octadienal, derive from the oxidation of fatty acids and have cytotoxic and anticancer effects. PUAs, tested separately, induce malformations in sea urchin Paracentrotus lividus embryos. Decadienal induces the worst malformations and lowest survival rates. Interestingly, decadienal, heptadienal and octadienal place in motion several genes to counteract their negative effects. To date, no studies are available reporting on the effects of PUA mixtures on marine invertebrates. Here we test binary and ternary mixtures on embryonic development of P. lividus. Our findings demonstrate that mixtures of PUAs act (i) at morphological level in synergistic way, being much more severe compared to individual PUAs; (ii) at molecular level also reveal an additive effect, affecting almost all fifty genes, previously tested using individual PUAs. This study is relevant from an ecological point of view since diatoms are a major food source for both pelagic and benthic organisms. This work opens new perspectives for understanding the molecular mechanisms that marine organisms use in reacting to environmental natural toxin mixtures such as diatom PUAs
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