DSpace Collection:

Mercury levels and neurotoxic potential of house dust extracts

Fri, 01 Nov 2019 00:00:00 GMT

Title: Mercury levels and neurotoxic potential of house dust extracts Authors: Barros, R; Sousa, Ana Catarina; Nepomuceno, M; Lanzinha, JCG; Cristovão, AC; Pastorinho, M. Ramiro Abstract: The quality of the indoor environment is affected by a set of factors that include, among others, the presence of environmental contaminants. These contaminants are potentially toxic and can negatively affect the health of the inhabitants. Therefore, their study is fundamental, especially considering that in Western societies about 90% of the time is spent inside what has been called the “built environment”. The evaluation of the indoor environment contamination has been increasingly performed using dust. This matrix acts as a reservoir and repository of chemicals that are simultaneously protected from the degradation processes occurring naturally in the external environment. Available studies are mainly based on chemical analyzes that do not allow to evaluate the toxicity in an integrated way, making the implementation of toxicological tests an imperative. In this work, we evaluated the levels of mercury, a well-known neurotoxicant, in house dust extracts collected under the framework of the 6x60x6 case study. The cytotoxic potential of these dust extracts were also analyzed in the dopaminergic neural cell line N27. The obtained results disclose a moderate neurotoxic potential of the different dust extracts analyzed and a statistically significant correlation between cell viability and mercury concentrations (p<0.05, r=0.900).

Acute toxicity of plant extracts towards Daphnia magna

Fri, 01 Nov 2019 00:00:00 GMT

Title: Acute toxicity of plant extracts towards Daphnia magna Authors: Ferraz, C; Pais, RT; Gaspar, C; Palmeira de Oliveira, A; Sousa, AC; Pastorinho, M. Ramiro Abstract: The demand for natural based products for the cosmetics industry is increasing sharply and therefore the search for new alternatives to the traditionally used plants is growing. These alternative plants can be an important source of bioactive compounds under a circular economy approach. Within the framework of Inovep project, several plant species, some of which autochthonous from Portugal, were identified as potential sources of bioactive compounds, namely: gum rockrose (Cistus ladanifer), curry plant (Helichrysum italicum), hop (Humulus lupulus), Mediterranean thyme (Thymbra capitata) and basil (Ocimum basilicum). Considering the potential future use of these plant extracts by the industry, it is necessary to assess the risk associated with their introduction into the ecosystem. This work aims to evaluate the toxic effects of different extracts of these five species. Acute toxicity tests using the model organism Daphnia magna were performed and the immobilization after 24 and 48 hours of exposure was evaluated. The EC50 (the concentration estimated to immobilize 50 per cent of the Daphnia) varied from 201.8±3.28 x10-5 mg.L-1 at 24 hours and 199.5±5.9410x10-5 mg.L-1 at 48 hours for Cistus ladanifer extract and 11.2±0.2403 mg.L- 1 at 24 hours and 11.2±0.4095 mg.L-1 at 48 hours for Thymbra capitata essential oil. For Humulus lupulus, Helichrysum italicum, Thymbra capitata in the form of hidrolate, and Ocimum basilicum no immobilization was observed until the highest concentrations tested for various types of extracts, suggesting these extracts present low to no risk towards D. magna.

Dietary exposure to Cadmium and the associated burden – results from a duplicate diet study in Portugal (2012)

Sat, 01 Feb 2020 00:00:00 GMT

Title: Dietary exposure to Cadmium and the associated burden – results from a duplicate diet study in Portugal (2012) Authors: Sousa, Ana; Assunção, R; Coelho, S; Kunisue, T; Tanabe, S; Pastorinho, M. Ramiro Abstract: Cadmium is a toxic metal classified as human carcinogen (Group 1) and considered an endocrine disruptor. Human exposure in the non-smoking general population occurs mainly via food ingestion. In order to evaluate the levels of Cd exposure trough food intake in Portugal and the associated burden, a duplicate diet study was conducted in the city of Aveiro, Portugal, in 2012.

Exploring frailty-related biomarkers and potential influence of environmental factors

Wed, 31 Jul 2019 23:00:00 GMT

Title: Exploring frailty-related biomarkers and potential influence of environmental factors Authors: Teixeira-Gomes, A; Lage, B; Sousa, Ana Catarina; Pastorinho, M. Ramiro; Carvalho, J; Valdiglesias, V; Laffon, B; Teixeira, J.P.; Costa, S. Abstract: Recent evidence advocates that healthy ageing may be possible, with morbidity compressed to later years. One area of concern is the burden of environmentally induced disease in susceptible populations. Older adults are a well-recognized susceptible population due to the decline of immune defences and the burden of multiple chronic diseases. As a susceptible population, the burden of environmentally induced disease and lifestyle factors is an increasing concern. Frailty is an age-related syndrome expected to increase over the next decades given the observed demographic shift. This syndrome has been identified to be the most common condition leading to disability, institutionalization and death in the older adults and the risk factors associated with its development are yet to be clarified. The main aim of the present study is to investigate a relation between frailty status, biomarkers and environmental exposures.