Organochlorine bioaccumulation and biomarkers levels in culture and wild white seabream (Diplodus sargus)

Persistent organic pollutants (POPs), which can accumulate in the adipose fish tissues, can enter the human food chain through the consumption of fish, and cause risk to health. The use of chemical analysis, and biochemical and cellular responses is a way to detect the impact of pollutants in aquatic systems. The purpose of this study was to investigate the levels of organochlorine compounds (polychlorinated biphenyls - PCB and p,p'-dichlorodiphenyltrichloroethane and its metabolites - tDDT) in, wild and cultivated, white seabream (Diplodus sargus), and also its biological effects that were evaluated by assessing the activity of biotransformation enzymes and genotoxic effects. To achieve that we have sampled five different size classes (I - 13 g, II - 64 g, III - 143 g, IV - 315 g and V - 441 g) of white seabream from a local aquaculture, and also a group of wild fish (375g) in order to compare accumulation and responses between cultured and wild fish. White seabream, cultured and wild, presented low levels of organochlorine content, both in liver and in muscle. Wild white seabream, in comparison to cultured ones at the marketable size, showed lower organochlorine accumulation. Biotransformation enzymes showed negative correlations with organochlorine levels in liver. Micronucleous numbers revealed that wild white seabream are not so exposed to genotoxic compounds as cultured ones.     

Isotherms and sequential extraction procedures for evaluating sorption and distribution of heavy metals in soils

Heavy metals are potentially toxic to human life and the environment. Their contaminating effect in soils depends on chemical associations. Hence, determining the chemical form of a metal in soils is important to evaluate its mobility and bioavailability. We utilized a sequential extraction procedure and sorption isotherms (monometal and competitive) to evaluate the mobility and distribution of Cd, Cu, Ni, Pb, and Zn in four soils differing in their physicochemical properties: Calcixerollic Xerochrepts (Cx1 and Cx2), Paralithic Xerorthent (Px) and Lithic Haplumbrept (Lh). Most of the metals retained under point B conditions of sorption isotherms were extracted from the more mobile fractions: exchangeable and carbonates, in contrast with the profiles of the original soils where metals were preferently associated with the residual fraction. In soils having carbonate concentration under 6% (Cx1 and Lh), the exchangeable fraction was predominant, whereas in calcareous soils (Cx2 and Px) metals extracted from carbonates predominated. Partitioning profiles were in accordance with the affinity sequences deduced from the initial slope of isotherms and showed that the soils had a greater number of surface sites and higher affinity for Pb and Cu than for Cd, Ni, or Zn. In general, the simultaneous presence of the cations under study increased the percentages of metals released in the exchangeable fraction. The tendency towards less specific forms was more noticeable in Cx2 and Px soils and for Ni, Zn, and Cd. The affinity of inorganic surfaces was larger for Zn than for Cd or Ni, but the affinity of organic surfaces was larger for Cd or Ni than for Zn.     

Coping and adaptation strategies and institutional perceptions of hydrological risk in an urban Amazonian city

This paper investigates coping and adaptation strategies and institutional perceptions of hydrological risk at the local scale in Santarém, an Amazonian city in the state of Pará, Brazil. Methods and tools of analysis encompassed secondary data, field observations, and qualitative techniques (focus-group discussions and in-depth interviews). Stakeholders from affected neighbourhoods describe their means of coping with and adapting to flooding, focusing on purposefulness, type of initiative and investment, risk timing, temporal and spatial scope, and performance. The results comprise an inventory of 16 mostly structural measures. The perceptions of six institutions of general responses to flooding are presented as opinions on actions that reduce the effects of such events, individual strategies and collective community endeavours in at-risk areas, and the activities of the public and private sectors to manage floods. Understanding of coping and adaptation strategies and knowledge of institutional flood risk perceptions can benefit the implementation of risk and disaster reduction policies and practices.     

Biological index based on epiphytic diatom assemblages is more restrictive than the physicochemical index in water assessment on an Amazon floodplain,Brazil

Environmental Science and Pollution Research - Canadian Water Quality Index (CWQI) provides protection for freshwater life promoting healthy ecosystems and safeguarding human health. Biological...     

Effects of paracetamol on the polychaete Hediste diversicolor: occurrence of oxidative stress,cyclooxygenase inhibition and behavioural alterations

Environmental Science and Pollution Research - Pharmaceuticals are significant environmental stressors, since they are utilized around the world; they are usually released in to the aquatic system...     

Feeding preferences of two detritivores related to size and metal content of leaves: the crustaceans Atyaephyra desmarestii (Millet) and Echinogammarus meridionalis (Pinkster)

The equilibrium of the structure and functioning of freshwater ecosystems is dependent of detritivores that link all the other functional groups. The preference for feeding leaves with different diameters (particle size) and leaves with metal contamination (several concentrations of the essential metals copper and zinc) were determined for two detritivores, the decapod Atyaephyra desmarestii and the amphipod Echinogammarus meridionalis. Several no-choice and multi-choice assays were done to determinate which leaf diameter the amphipod and the decapod species would eat when they had or not had alternatives available and include a set of dual-choice assays with contaminated and uncontaminated foods. No significant preference was shown by either species relative to the diameter of leaves, either on no-choice or multi-choice assays. The presence of essential metals on food did not had any influence on the feeding choice of these organisms over the concentration range studied. Both showed no preference on ingesting food spiked with these essential metals, except E. meridionalis which preferred ingesting leaves with 2.19 μg.l^?1 of copper instead of uncontaminated leaves. For further works, despite no preference for leaves with a certain diameter, the leaves with 0.70 cm (0.385 cm²of area) and with 0.50 cm (1.767 cm² of area) should be used for A. desmarestii and E. meridionalis, respectively. Furthermore, to maintain E. meridionalis, the diet should include some percentage of copper in order to accomplish metabolic needs.     

Cork stoppers as an effective sorbent for water treatment: the removal of mercury at environmentally relevant concentrations and conditions

The technical feasibility of using stopper-derived cork as an effective biosorbent towards bivalent mercury at environmentally relevant concentrations and conditions was evaluated in this study. Only 25 mg/L of cork powder was able to achieve 94 % of mercury removal for an initial mercury concentration of 500 μg/L. It was found that under the conditions tested, the efficiency of mercury removal expressed as equilibrium removal percentage does not depend on the amount of cork or its particle size, but is very sensitive to initial metal concentration, with higher removal efficiencies at higher initial concentrations. Ion exchange was identified as one of the mechanisms involved in the sorption of Hg onto cork in the absence of ionic competition. Under ionic competition, stopper-derived cork showed to be extremely effective and selective for mercury in binary mixtures, while in complex matrices like seawater, moderate inhibition of the sorption process was observed, attributed to a change in mercury speciation. The loadings achieved are similar to the majority of literature values found for other biosorbents and for other metals, suggesting that cork stoppers can be recycled as an effective biosorbent for water treatment. However, the most interesting result is that equilibrium data show a very rare behaviour, with the isotherm presenting an almost square convex shape to the concentration axis, with an infinite slope for an Hg concentration in solution around 25 μg/L.     

Monitoring the effectiveness of the European tributyltin regulation on the Basque coast (northern Spain) by assessing imposex in two gastropod species (Nassarius reticulatus and Nassarius nitidus)

Imposex and butyltin body burden were assessed in 2011 along the Basque coast (northern Spain) in two gastropod species (Nassarius reticulatus and Nassarius nitidus) four years after an initial survey in 2007. The aim of this re-survey was to monitor the effectiveness of the European ban on the use of tributyltin (TBT) based antifouling paints on ships’ hulls (EC 782/2003). Imposex levels in 2011 were lower than those determined in 2007 at most of the sampling sites. Accordingly, TBT concentrations in the female body burden of Nassarius reticulatus varied from 43 to 250 ng Sn/g in dry weight in 2011, which was a lower maximum than in 2007. Nevertheless, the results for the butyltin degradation index suggest that there have been recent inputs of TBT within the two main Basque harbours. Overall, the legislative measure is contributing to the reduction of TBT effects on the Basque coast although its presence is still evident.     

Study of controlled migration of cadmium and lead into foods from plastic utensils for children

Lead (Pb) is a highly neurotoxic chemical element known for reducing intelligence quotient (IQ) and promoting antisocial behavior in children and adolescents, while cadmium (Cd) is a carcinogenic bioaccumulative element. Both these metals are included in the priority pollutant list of the United States Environmental Protection Agency and in the WHO List of Chemicals of Major Public Health Concern, where contaminated foods and beverages are the most common pathways of exposure. The objective of this study was to determine total Cd and Pb levels in colored plastic utensils (cups, mugs, bowls, feeding bottles, and plates) for use by children and to measure the specific migration of these elements into beverages and foods. Total contaminant levels were determined using a handheld X-ray fluorescence analyzer. Specific migration tests were conducted using the simulant solutions acetic acid 3% (m/v) and water. Migration levels were determined by ICP-MS. Specific migration tests for Pb were also performed on commercially available samples (cola soft drink, orange juice, vinegar, and milk), with levels determined by graphite-furnace atomic absorption spectrometry (GF-AAS). A total of 674 utensils were analyzed in loco at major commercial centers in Greater São Paulo, of which 87 were purchased for containing Cd and Pb concentrations above permitted limits. Mean concentrations of the metals detected in the purchased utensils were 1110 ppm for Pb and 338 ppm for Cd. For specific migration assays, Pb levels were 187, 13, and 380 times above the permitted limit (0.01 mg.kg -1) for acetic acid, water, and orange juice, respectively. Cd levels were 50 and 2.4 times above the maximum permitted limit (0.005 mg.kg -1) for acetic acid and water, respectively. The districts where the utensils were purchased were grouped according to their social vulnerability index and compared using ANOVA. Pb levels were different between low and medium/high social vulnerability groups (p?=?0.006). The findings corroborate the initial hypothesis that these utensils constitute a major source of exposure to PTEs such as Cd and Pb, pointing to the need for stricter regulation and inspection by the Brazilian regulatory agencies.

     

A socioeconomic and natural vulnerability index for oil spills in an Amazonian harbor: A case study using GIS and remote sensing

The coastal zone of the Brazilian state of Maranhão is an area characterized by a large variety of human activities and services, in particular in the Itaqui-Bacanga port complex (IBC). The IBC is an area prone to oil spills resulting from the processes of transportation, storage, and tank cleaning. The present study aimed to map the different physical environments adjacent to this complex and the socioeconomic profile of the local population that would be most vulnerable to this type of disaster. Vulnerability studies are essential as one of the first step in the development of an integrated coastal zone management. The variables analyzed in this study included geomorphological units, and the income, education, and dependence on fishing of the local population. The estimate of the vulnerability index was based on the relationships between these variables, which were used to generate a vulnerability map using GIS and the interpretation of high-resolution remote sensing, showing the areas of highest priority for intervention in the case of oil spills. The analysis of the natural and socioeconomic environments indicated that the areas of highest vulnerability correspond to the mangroves and the Vila Nova and Alto da Esperança neighborhoods, respectively. These neighborhoods have a direct relationship with fishing, and low levels of both income and education. By contrast, the lowest vulnerability was attributed to the coastal plateau and the central Anjo da Guarda neighborhood, which is occupied by residents with relatively high income and education, who do not depend on fishing.