Browsing by Author "Santos, Miguel Machado"
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- Toxicity testing of simvastatin, sertraline, 4-MBC propylparaben and triclocarban using zebrafish and sea urchin embryos bioassaysPublication . Torres, Tiago; Ribeiro, Sílvia; Cunha, Isabel; Martins, Rosário; Santos, Miguel MachadoIn the past decade, many emergent compounds, including some active substances and ingredients of Pharmaceuticals and Personal Care Products (PPCPs) have been detected in water at levels that can negatively impact aquatic ecosystems (Lapworth et al., 2012; Jiang et al., 2013). The recent knowledge of their occurrence has raised concerns about human health effects and ecosystem risks. Although these compounds are frequently detected at concentrations that are not likely to induce adverse effects in humans and may be too low to cause acute effects in other organisms, there is still a serious lack of information about the effects in non-target species, particularly considering chronic exposure or effects resulting from interactions between them (Lapworth et al., 2012). Pharmaceuticals and Personal Care Products enter the aquatic environment from different point and nonpoint sources and wastewater treatments plants cannot ensure complete removal of many compounds, and therefore they may be present at significant concentrations in effluents (Jiang et al., 2013). Hence, it is essential to understand the effects of these substances on aquatic organisms. Owing to the large number of new chemicals that must go through toxicity testing, short-term early-life-stages have been frequently used as an alternative to long-term exposures due to its high sensitivity and logistic advantages.
- Using early life stages of marine animals to screen the toxicity of priority hazardous and noxious substancesPublication . Cunha, Isabel; Torres, Tiago; Oliveira, Helena; Martins, Rosário; McGowan, Thomas; Sheahan, David; Santos, Miguel MachadoThis study provides toxicity values for early life stages (ELS) of two phylogenetically distinct marine animal taxa, the sea urchin (Paracentrotus lividus), a deuterostome invertebrate, and the turbot (Scophthalmus maximus), a vertebrate (teleost), when challenged by six hazardous and noxious substances (HNS): aniline, butyl acrylate, m-cresol, cyclohexylbenzene, hexane and trichloroethylene. The aim of the study was to provide preliminary information on toxic effects of representative and relevant priority HNS to assess the risk posed by spills to marine habitats and therefore improve preparedness and the response at the operational level. Selection criteria to include each compound in the study were (1) inclusion in the HASREP (2005) list; (2) presence on the priority list established by Neuparth et al. (2011); (3) paucity of toxicological data (TOXnet and ECOTOX) for marine organisms; (4) behaviour in the water according to the categories defined by the European Behaviour classification system (GESAMP 2002), by selecting compounds with different behaviours in water; and (5) physicochemical and toxicological properties, where available, in order to anticipate the most toxic compounds. Aniline and m-cresol were the most toxic compounds with no observed apical effect concentration (NOAEC) values for sea urchin ranging between 0.01 and 0.1 mg/L, followed by butyl acrylate and cyclohexylbenzene with NOAECs ranging between 0.1 and 1.0 mg/L and trichloroethylene with NOAEC values that were in the range between 1 and 10 mg/L, reflecting their behaviour in water, mostly vapour pressure, but also solubility and log Kow. Hexane was toxic only for turbot embryos, due to its neurotoxic effects, and not for sea urchin larvae, at concentrations in the range between 1 and 10 mg/L. The concentrations tested were of the same order of magnitude for both species, and it was observed that sea urchin embryos (length of the longest arm) are more sensitive than turbot eggs larvae (hatching and cumulative mortality rates) to the HNS tested (except hexane). For this specific compound, concentrations up to 70 mg/L were tested in sea urchin larvae and no effects were observed on the length of the larvae. Both tests were found to be complementary depending on behaviour in water and toxicity target of the compounds analysed.