Assessing the trophic state of Linhos lake: a first step towards ecological rehabilitation

Lack of recognition of the value of wetlands has led to the loss of considerable areas of these ecosystems in the past. Linhos lake (Figueira da Foz, Portugal) is a good example of one of these ecosystems, in which human intervention was responsible for its environmental degradation and led to its precocious terrestrialization. Physico-chemical conditions and zooplankton community structure were studied in Linhos lake, in order to evaluate ecosystem functioning and to acquire baseline information. The system is characterised by high oxygen depletion. Spatial heterogeneity was confirmed by the existence of significant differences in total densities for the three zooplanktonic groups. Rotifers were the most abundant group attaining their maximum density in April (2251 x 1 ind/l). Keratella quadrata, K. cochlearis, Polyarthra vulgaris, Filinia terminalis and Hexarthra mira were the main abundant species. Correspondence analysis suggested temperature as the main controlling factor in species seasonality. In order to prevent the precocious disappearance of the lake some restoration measures were proposed based on zooplankton community structure.     

Untreated abandoned mercury mining works in a scenic area of Asturias (Spain)

Mercury mining was a large and thriving industry during the last century in Asturias (NW Spain). At Bra?alamosa, mining activity introduced significant quantities of wastes in spoil heaps located close to the mining operations. In these mining wastes, in addition to mercury, high concentrations of other potentially dangerous elements like As have been found. As a consequence, pollution and dereliction of the local environment occurred. This paper focuses on the environmental impact of these old mining operations and describes a preliminary assessment of the extent of contamination. This includes analytical data from systematic sampling of soils, stream sediments, wastes from spoil heaps, water and herbaceous plants in areas affected by mining activities. The potential risk that spoil materials imply for human health and the environment is documented on the basis of the application of EPA Risk Assessment methodology.     

Modelling and simulation of inhibition-injection systems applied to polymerization reactors

The most critical aspect of polymerization reactors is the agitator's stop and becomes more serious when this occurs exactly at the removal of the heat load, which is generated by the reaction (exothermic). This phenomenon is typical in power-failure situations of the energy supply or because of other related problems at the plant. The objective of this work is to compare the performance of two configurations for the inhibition-injection system for vinyl chloride monomer (VCM) polymerization reactors. To determine the injection time a rigorous mathematical model was developed. From the results of this work one of the configurations was implemented in an industrial plant.     

Metaphase analysis, micronuclei assay, and urinary mutagenicity assay of mice exposed to diesel emissions

Female Swiss mice were exposed 8 h/day to diesel exhaust for 1, 3, and 7 weeks. Urine was collected overnight for 4 days prior to sacrifice while the mice continued to be exposed for eight hours during the day. The presence of mutagens was determined by the Ames Salmonella test. One hour prior to sacrifice each mouse received 1 mg/kg colcemide. After sacrifice, the marrow from each femur was obtained. The marrow from one femur was used to prepare slides for metaphase analysis and the other for micronuclei assay. Other mice received IP 50 mg/kg cyclophosphamide 24 h prior to sacrifice or 1 μmole/kg benzo(a)pyrene in each of four daily doses prior to sacrifice and served as positive controls. The Ames Salmonella assay of the unconcentrated urine after 1, 3, and 7 weeks and concentrated urine after 7 weeks exposure to diesel exhaust did not significantly vary from clean air controls. In the micronucleus test, and metaphase analysis, cyclophosphamide produced a strong positive response and the 7 week diesel exposure was not different from clean air controls.     

Environmental remediation processes by zero valence copper: reaction mechanisms

Environmental Science and Pollution Research - Recent studies have shown Cu(0) as a promising material for the removal of organic and inorganic pollutants. However, there is no review addressing...     

Policy-adaptation for a smarter and more sustainable EU electricity distribution industry: a foresight analysis

The European Union (EU) transition to a smarter and more sustainable electricity sector is driven by climate change adaptation and technological developments. For the electricity distribution industry, this has contributed to a growing need to understand how these network monopolies should adapt their role, activities, and responsibilities for a redesigned electricity market, given the growth of distributed generation, and the increased control and monitoring capabilities. Considering this, a foresight study on business model innovation, technological adaptation, and market design policy alternatives is presented. A Policy Delphi method was applied, involving two iterative survey rounds and 207 European experts, which assessed 57 policy alternatives. The results highlight adaptation challenges for implementing new technologies and business practices. Experts support innovation and transition to new roles, and innovative services, while warranting that core electricity distribution activities are secured. This shift in roles is expected to be achieved through research and development (R&D) support policies, innovation friendly regulatory frameworks, and concerted actions at the EU and Member States level. The results provide policy-adaptation guidelines for electricity distribution industry stakeholders.     

Pharmacopollution and Household Waste Medicine (HWM): how reverse logistics is environmentally important to Brazil

Pharmacopollution is a public health and environmental outcome of some active pharmaceutical ingredients (API) and endocrine-disrupting compounds (EDC) dispersed through water and/or soil. Its most important sources are the pharmaceutical industry, healthcare facilities (e.g., hospitals), livestock, aquaculture, and households (patients’ excretion and littering). The last source is the focus of this article. Research questions are “What is the Household Waste Medicine (HWM) phenomenon?”, “How HWM and pharmacopollution are related?”, and “Why is a reverse logistic system necessary for HWM in Brazil?” This article followed the seven steps proposed by Rother (2007) for a systematic review based on the Cochrane Handbook and the National Health Service (NHS) Center for Reviews Dissemination (CDR) Report. The HWM phenomenon brings many environmental, public health, and, social challenges. The insufficient data is a real challenge to assessing potential human health risks and API concentrations. Therefore, the hazard of long-term exposure to low concentrations of pharmacopollutants and the combined effects of API mixtures is still uncertain. HWM are strongly related to pharmacopollution, as this review shows. The Brazilian HWM case is remarkable because it is the fourth pharmaceutical market (US$ 65,971 billion), with a wide number of private pharmacies and drugstores (3.3: 10,000 pharmacy/inhabitants), self-medication habits, and no national take-back program. The HWM generation is estimated in 56.6 g/per capita, or 10,800 t/year. The absence of a reverse logistics for HWM can lead to serious environmental and public health challenges. The sector agreement for HWM is currently under public consultation.     

Identification of protein biomarkers of mercury toxicity in fish

Bioaccumulative metals such as mercury are found in increasing amounts in fish and their consumers. In the region of the Madeira River, in the Brazilian Amazon, mercury (Hg) is a predominant contaminant in the aquatic ecosystem. There is therefore a need to find specific biomarkers of mercury toxicity in fish to monitor contaminations. Here, mercury-bound proteins were identified in the liver tissues of fishes Mylossoma duriventre and Brachyplatystoma rousseauxii. Mercury was quantified in liver tissue, pellets and protein spots by graphite furnace atomic absorption. Proteins were fractionated by two-dimensional polyacrylamide gel electrophoresis and identified by mass spectrometry with electrospray ionization. We identified nine proteins linked to mercury and that presented biomarker characteristics of mercury. Among the proteins identified, isoforms of parvalbumin, ubiquitin-40S ribosomal protein S27a, brain-specific angiogenesis inhibitor 1-associated protein 2-like protein 2 and betaine–homocysteine S-methyltransferase 1 are notable for having the molecular function of binding to metallic ions.     

Time Series Forecasting of Cyanobacteria Blooms in the Crestuma Reservoir (Douro River, Portugal) Using Artificial Neural Networks

In this work, time series neural networks were used to predict the occurrence of toxic cyanobacterial blooms in Crestuma Reservoir, which is an important potable water supply for the Porto region, located in the north of Portugal. These models can potentially be used to provide water treatment plant operators with an early warning for developing cyanobacteria blooms. Physical, chemical, and biological parameters were collected at Crestuma Reservoir from 1999 to 2002. The data set was then divided into three independent time series, each with a fortnightly periodicity. One training series was used to “teach” the neural networks to predict results. Another series was used to verify the results, and to avoid over-fitting of the data. An additional independently collected data series was then used to test the efficacy of the model for predicting the abundance of cyanobacteria. All of the models tested in this study incorporated a prediction time (look-ahead parameter) equal to the sampling interval (two weeks). Various lag periods, from 2 to 52 weeks, were also investigated. The best model produced in this study provided the following correlations between the target and forecast values in the training, verification, and validation series: 1.000 (P = 0.000), 0.802 (P = 0.000), and 0.773 (P = 0.001), respectively. By applying this model to the three-year data set, we were able to predict fluctuations in cyanobacteria abundance in the Crestuma Reservoir, with a high level of precision. By incorporating a lag-period of eight weeks, we were able to detect secondary fluctuations in cyanobacterial abundance over the annual cycle.     

Bacterial response to dynamic metal concentrations in the surface sediments of a solar saltern (Goa, India)

The Ribandar solar saltern, situated adjacent to the Mandovi estuary is influenced by the barge transport of ferromanganese ore to the Mormugao harbour (Arabian Sea). The current study focuses on the distribution of metals and related heterotrophic bacterial populations in the surface sediments (0–10 cm) of the Ribandar salterns (Goa, India) during the salt-making (January to May) and non salt-making seasons (August and November). The concentrations of heavy metals in the sediments ranged from 17.2?±?2.8 to 26.3?±?6.7 % Fe; 0.6?±?0.2 to 0.9?±?0.2 % Mn; 27.6?±?7.3 to 51?±?8.3 ppm Ni; 28.4?±?8.9 to 35.2?±?10.6 ppm Co; 44?±?21.6 to 62.8?±?23.6 ppm Zn; 0.1?±?0.01 ppm Cd and 1.7?±?0.1 to 2.6?±?0.7 ppm Pb and were much higher than those reported at the same site in a previous study by Kerkar (2004). Hg concentrations were below detection limits. In general, computation of “geoaccumulation index” revealed the sediments as ‘uncontaminated to moderately contaminated’ with Fe, Mn, Ni, Co, Pb and Zn during the salt-making season. The abundance of metal-tolerant bacteria was comparatively restricted to the salt-making season and was higher than the non salt-making season. Fe-, Mn-, Ni-, Co- and Pb- (200 ppm) tolerant bacteria were retrieved and restricted to the surface sediments (0–5 cm), Cd and Fe being the two most regulatory elements governing bacterial populations in the non salt-making season. However, during the salt-making season, the concentration of Zn was found to be pivotal in regulating the counts of Fe-, Mn- and Ni-tolerant bacteria. In general, the strength of correlation of metals and microbes was higher in the non salt-making season as compared to the salt-making season. This would probably indicate metal-induced limitations in microbial populations in the non salt-making season and the absence of this effect during the salt-making season. In this study, we test the hypothesis that solar salterns behave as ecological sinks with a potential to transform native bacterial populations to metal-resistant strains, in relation to the dynamic changes in the surrounding metal concentrations.