Bisphenol A migration from plastic materials: direct insight of ecotoxicity in Daphnia magna

Bisphenol A (BPA) is an endocrine disrupting chemical (EDC) whose migration from food packaging is recognized worldwide. However, the real overall food contamination and related consequences are yet largely unknown. Among humans, children’s exposure to BPA has been emphasized because of the immaturity of their biological systems. The main aim of this study was to assess the reproductive impact of BPA leached from commercially available plastic containers used or related to child nutrition, performing ecotoxicological tests using the biomonitoring species Daphnia magna. Acute and chronic tests, as well as single and multigenerational tests were done. Migration of BPA from several baby bottles and other plastic containers evaluated by GC-MS indicated that a broader range of foodstuff may be contaminated when packed in plastics. Ecotoxicological test results performed using defined concentrations of BPA were in agreement with literature, although a precocious maturity of daphnids was detected at 3.0 mg/L. Curiously, an increased reproductive output (neonates per female) was observed when daphnids were bred in the polycarbonate (PC) containers (145.1±4.3 % to 264.7±3.8 %), both in single as in multigenerational tests, in comparison with the negative control group (100.3±1.6 %). A strong correlated dose-dependent ecotoxicological effect was observed, providing evidence that BPA leached from plastic food packaging materials act as functional estrogen in vivo at very low concentrations. In contrast, neonate production by daphnids cultured in polypropylene and non-PC bottles was slightly but not significantly enhanced (92.5±2.0 % to 118.8±1.8 %). Multigenerational tests also revealed magnification of the adverse effects, not only on fecundity but also on mortality, which represents a worrying trend for organisms that are chronically exposed to xenoestrogens for many generations. Two plausible explanations for the observed results could be given: a non-monotonic dose–response relationship or a mixture toxicity effect.

Radiation dose rates and exposure associated to Technologically Enhanced Naturally Occurring Radioactive Materials (TENORM) at locations of a Portuguese coal-fired power plant

Coal contains trace quantities of natural radionuclides such as Th-232, U-235, U-238, as well as their radioactive decay products and 40K. These radionuclides can be released as fly ash in atmospheric emissions from coal-fired power plants, dispersed into the environment and deposited on the surrounding top soils. Therefore, the natural radiation background level is enhanced and consequently increase the total dose for the nearby population. A radiation monitoring programme was used to assess the external dose contribution to the natural radiation background, potentially resulting from the dispersion of coal ash in past atmospheric emissions. Radiation measurements were carried out by gamma spectrometry in the vicinity of a Portuguese coal-fired power plant. The radiation monitoring was achieved both on and off site, being the boundary delimited by a 20 km circle centered in the stacks of the coal plant. The measured radionuclides concentrations for the uranium and thorium series ranged from 7.7 to 41.3 Bq/kg for Ra-226 and from 4.7 to 71.6 Bq/kg for Th-232, while K-40 concentrations ranged from 62.3 to 795.1 Bq/kg. The highest values were registered near the power plant and at distances between 6 and 20 km from the stacks, mainly in the prevailing wind direction. The absorbed dose rates were calculated for each sampling location: 13.97-84.00 ηGy/h, while measurements from previous studies carried out in 1993 registered values in the range of 16.6-77.6 ηGy/h. The highest values were registered at locations in the prevailing wind direction (NW-SE). This study has been primarily done to assess the radiation dose rates and exposure to the nearby population in the surroundings of a coal-fired power plant. The results suggest an enhancement or at least an influence in the background radiation due to the coal plant past activities.

Radioactivity levels of 238U and 232Th decay series and related dose rates in the surroundings of a coal power plant using high resolution g-spectrometry

Gamma radiations measurements were carried out in the vicinity of a coal-fired power plant located in the southwest coastline of Portugal. Two different gamma detectors were used to assess the environmental radiation within a circular area of 20 km centred in the coal plant: a scintillometer (SPP2 NF, Saphymo) and a high purity germanium detector (HPGe, Canberra). Fifty urban and suburban measurements locations were established within the defined area and two measurements campaigns were carried out. The results of the total gamma radiation ranged from 20.83 to 98.33 counts per second (c.p.s.) for both measurement campaigns and outdoor doses rates ranged from 77.65 to 366.51 Gy/h. Natural emitting nuclides from the U-238 and Th-232 decay series were identified as well as the natural emitting nuclide K-40. The radionuclide concentration from the uranium and thorium series determined by gamma spectrometry ranged from 0.93 to 73.68 Bq/kg, while for K-40 the concentration ranged from 84.14 to 904.38 Bq/kg. The obtained results were used primarily to define the variability in measured environmental radiation and to determine the coal plant’s influence in the measured radiation levels. The highest values were measured at two locations near the power plant and at locations between the distance of 6 and 20 km away from the stacks, mainly in the prevailing wind direction. The results showed an increase or at least an influence from the coal-fired plant operations, both qualitatively and quantitatively.

Effects of hotel characteristics on room rates in Porto: a hedonic price approach

According to the hedonic price method, a price of a good is related with the characteristics or the services it provides. Within this framework, the aim of this study it is to examine the effect on room rates of different characteristics of hotels in and around the city of Porto, such as star category, size, room and service quality, hotel facilities and location. It was estimated a hedonic price function, using data for 51 hotels. The results enable to identify the attributes that are important to consumers and hoteliers and to which extent. This information can be used by hotel managers to define a price strategy and helpful in new investment decisions.

Preservação digital nas médias e grandes empresas portuguesas: estudo de caso e recomendação de boas práticas

Este estudo tem como objetivo analisar o estado atual da preservação digital no tecido empresarial português, particularmente nas empresas de média e grande dimensão. Para tal, expôs-se o referencial teórico da preservação digital, necessário para uma melhor compreensão desta temática, nomeadamente através da apresentação de definições de diversos autores, de estratégias e boas práticas, e de algumas das iniciativas internacionais mais relevantes. De seguida apresentou-se a importância que a informação tem para uma organização, sobretudo aquela informação criada no âmbito laboral. Realizou-se, também, uma caracterização dos vários tipos de empresas, de acordo com diretivas europeias, e efetuou-se uma breve análise das empresas portuguesas. Para atingir esse objetivo elaborou-se um inquérito, por questionário, fazendo- se uso de uma plataforma de questionários online. Este foi remetido a 1.358 médias e grandes empresas que atuam em Portugal, com o objetivo de compreender – entre outros – a importância dada, pelas empresas, ao material existente em formato digital, quais as tecnologias responsáveis pelo seu armazenamento e quais os cuidados realizados para assegurar o seu acesso por longos períodos de tempo. Ao analisar os resultados, e pese embora a baixa taxa de resposta ao questionário, foi possível concluir que quase todas as empresas participantes já procuram substituir os documentos em papel por documentos em formato digital e que se preocupam em manter o acesso prolongado à informação. Não obstante, dois terços dos participantes conhecem o conceito de preservação digital e apenas 44% afirmam aplicar estratégias desse tipo na sua empresa. Apesar de cerca de 70% dos participantes reconhecerem a importância do uso de formatos abertos para a preservação digital, na realidade ainda se verifica uma utilização massiva de formatos proprietários ao nível dos documentos de texto e das folhas de cálculo. Para além deste contributo analítico sobre o estado da preservação digital no tecido empresarial português, prepararam-se alguns documentos que visam auxiliar a elaboração de um plano de preservação digital e, consequentemente, permitir a sustentabilidade a longo prazo da informação digital.