Effect of diflubenzuron on the development of Pinus pinaster seedlings inoculated with the ectomycorrhizal fungus Pisolithus tinctorius

Diflubenzuron (DFB) is an insecticide commonly used to control forest pests. The objectives of this study were to assess the effect of diflubenzuron on the development of Pinus pinaster seedlings and Pisolithus tinctorius under laboratory conditions and to study the possible protective role of this ectomycorrhizal fungus against the effects of diflubenzuron. In vitro experiments revealed that diflubenzuron inhibited fungal growth at all tested concentrations (0.01, 0.1, 1, 10 and 100 mg L^?1). Root growth was inhibited at the two highest diflubenzuron concentrations. The activity of the antioxidant defence system of non-inoculated P. pinaster increased at 1 and 10 mg DFB kg^?1 substrate, and inoculation increased the threshold to the highest concentration. The protective role of the ectomycorrhizal fungus was seen in the increase of CAT activity. This study revealed that despite causing no mortality, diflubenzuron has the ability to cause sub-lethal damage to P. pinaster. The disproportionate use of this insecticide may lead to higher amounts of its residues in soil and the biosphere, endangering trees, fungi and their symbiosis.     

Road traffic impact on urban atmospheric aerosol loading at Oporto,Portugal

At urban areas in south Europe atmospheric aerosol levels are frequently above legislation limits as a result of road traffic and favourable climatic conditions for photochemical formation and dust suspension. Strategies for urban particulate pollution control have to take into account specific regional characteristics and need correct information concerning the sources of the aerosol.With these objectives, the ionic and elemental composition of the fine (PM_2.5) and coarse (PM_2.5–10) aerosol was measured at two contrasting sites in the centre of the city of Oporto, roadside (R) and urban background (UB), during two campaigns, in winter and summer.Application of Spatial Variability Factors, in association with Principal Component/Multilinear Regression/Inter-site Mass Balance Analysis, to aerosol data permitted to identify and quantify 5 main groups of sources, namely direct car emissions, industry, photochemical production, dust suspension and sea salt transport. Traffic strongly influenced PM mass and composition. Direct car emissions and road dust resuspension contributed with 44–66% to the fine aerosol and with 12 to 55% to the coarse particles mass at both sites, showing typically highest loads at roadside. In fine particles secondary origin was also quite important in aerosol loading, principally during summer, with 28–48% mass contribution, at R and UB sites respectively. Sea spray has an important contribution of 18–28% to coarse aerosol mass in the studied area, with a highest relative contribution at UB site.Application of Spatial Variability/Mass Balance Analysis permitted the estimation of traffic contribution to soil dust in both size ranges, across sites and seasons, demonstrating that as much as 80% of present dust can result from road traffic resuspension.     

Evaluation of violations in water quality standards in the monitoring network of São Francisco River basin,the third largest in Brazil

The São Francisco River is the largest river located entirely within Brazil, and water scarcity problems have been a major concern of Brazilian society and government. Water quality issues are also a concern and have worsened with the recent intensification of urbanization and industrialization. In this study, violations to water quality standards established by local legislation were calculated as a percentage for 26 selected parameters over a monitoring period of 14 years. The violation percentages were analyzed spatially using the Kruskal-Wallis test, followed by multiple comparison analysis. Temporal analysis was performed using the Mann-Kendall test and Spearman correlation. Some parameters could be identified as cause for concern due to high violation levels, such as the fecal coliform indicator (FCI) and phosphorus—both related to domestic and effluent disposal without treatment or with insufficient treatment—and color, turbidity, manganese, and total suspended solids—which can be affected by erosive processes of natural and anthropogenic causes. The study found that these violations are concentrated in the most urbanized and industrialized areas of the basin. Some metallic parameters, such as iron and arsenic violations, may be related to mining activities in the rich soil of the Iron Quadrangle area located within the Minas Gerais State. Trend analysis results indicated that most monitoring stations did not have significant modification (elevation or reduction) trends over time, which, together with the high violation percentages, might indicate the maintenance of a scenario of constant pressure upon water resources, in particular in those more urbanized areas.     

Direct electrochemical detection of glyphosate at carbon paste electrode and its determination in samples of milk,orange juice,and agricultural formulation

Abstract

This paper describes a simple, inexpensive, highly sensitive, selective, and efficient electrochemical method to determine glyphosate (GLY) in samples of milk, orange juice, and agricultural formulation. The oxidation reaction on the electrode surface was electrochemically characterised by cyclic voltammetry (CV) and square wave voltammetry (SWV). The investigation of GLY at carbon paste electrode revealed a non-reversible oxidation peak at +0.95 V versus Ag/AgCl, which was used for electrochemical detection of GLY. The operating parameters (pH, frequency, step potential, and amplitude) were optimised in relation to the peak current intensity, and a calibration curve was set up in a concentration range of 4.40?×?10^?8–2.80?×?10^?6 mol L^?1, with a detection limit of 2?×?10^?9 mol L^?1. After calibration curve was plotted, the developed procedure was applied to determine GLY in previously contaminated samples: milk and orange juice, and in a commercial formulation, obtaining recovery values between 98.31% and 103.75%. These results show that the proposed method can be used for GLY quantification in different samples with high sensitivity, specificity, stability, and reproducibility.     

Moral Disengagement in Harmful but Cherished Food Practices? An Exploration into the Case of Meat

Harmful but culturally cherished practices often endure in spite of the damages they cause. Meat consumption is increasingly becoming one of such cases and may provide an opportunity from which to observe these phenomena. Growing evidence indicates that current and projected production and consumption patterns are important contributors to significant environmental problems, public health degradation, and animal suffering. Our aim is to contribute to a further understanding of the psychological factors that may hinder or promote personal disposition to change food habits to benefit each of these domains. Drawing from previous evidence, this study explores the proposition that some consumers are motivated to resort to moral disengagement strategies when called upon to consider the impacts of their food habits. Data were collected from six semi-structured focus groups with a sample of 40 participants. Although affirming personal duties towards preserving the environment, promoting public health, and safeguarding animal welfare, participants did not show personal disposition to change their meat consumption habits. Several patterns of response that resonate with the principles of moral disengagement theory (i.e. reconstrual of the harmful conduct; obscuring personal responsibility; disregard for the negative consequences; active avoidance and dissociation) were observed while discussing impacts and the possibility of change. Results seem to support the proposition that the process of moral disengagement may play a role in hindering openness to change food habits for the benefit of the environment, public health, and animals, and point towards the relevance of further exploring this approach.     

Bioaccumulation of chlorinated pesticides and PCBs in the tropical freshwater fish Hoplias malabaricus: histopathological, physiological, and immunological findings

For assessing the impact of chlorinated compounds, such as organochlorine pesticides, polychlorinated biphenyls, chlorotriazines (atrazine, simazine), and chlorinated phenylureas (diuron), on the Ponta Grossa lake South of Brazil, ten freshwater trahira fish (Hoplias malabaricus) were collected in October 2005. The contamination status was evaluated by the energy budget and various histopathological markers. The results showed detectable amounts of persistent organic pollutants (POPs) in the liver and muscle; the bioaccumulation was higher in the liver than in the muscle. The presence of some banned pesticides, such as hexachlorobenzene and dichlorodiphenyltrichloroethane, in the liver suggests an acute exposure to these compounds. Some physiological disturbances and morphological damages found in the liver of H. malabaricus were associated with chlorinated-compound bioaccumulation. The most important alterations in the liver were lesions such as fibrosis, large necrosis area, leukocyte infiltration, and the absence of melanomacrophages (MM). Individuals containing higher concentrations of pesticides, such as aldrin, alachlor, and dichloroaniline (a metabolite of diuron), showed the nonoccurrence of MM in the liver. These data suggest an immunosuppression in the individuals from Ponta Grossa Lake after exposure to POPs. According to the present data, the POPs found in the studied site are bioavailable, induce severe damages in target organs such as the liver, and can disturb the immune system of the trahira. This is the first study of POPs in the Paraná state, and one among the few studies in the south of Brazil. The present data suggest and motivate further chemical and biomonitoring studies in freshwater ecosystems in the south of Brazil.     

Reconnaissance of submarine groundwater discharge at Ubatuba coast,Brazil, using 222Rn as a natural tracer

Submarine groundwater discharge (SGD), which includes fresh groundwater and recycled seawater, has been recognized as a widespread phenomenon that can provide important chemical elements to the ocean. Several studies have demonstrated that SGD may approach or even exceed freshwater sources in supplying nutrients to coastal zones. This work reports preliminary results of a study carried out in a series of small embayments of Ubatuba, S?o Paulo State, Brazil, covering latitudes between 23 degrees 26'S and 23 degrees 46'S and longitudes between 45 degrees 02'W and 45 degrees 11'W. The main aims of this research were to set up an analytical method to assess 222Rn and 226Ra activities in seawater samples and to apply the excess 222Rn inventories obtained to estimate SGD. Measurements made during the summer of 2001 included 222Rn and 226Ra in seawater, 226Ra in sediment, seawater and sediment physical properties, nutrients and seepage rates. A continuous 222Rn monitor was also used to determine in situ collection of data to study short-term changes at one location. All methods indicated significant inflow of subsurface fluids at rates in excess of several cm per day.     

An ecotoxic risk assessment of residue materials produced by the plasma pyrolysis/vitrification (PP/V) process

Plasma is the fourth state of matter, following the three states of solid, liquid and gas. Experience has amply demonstrated that solids exposed to the oxygen-deficient plasma flame are converted to liquid, and liquid exposed to the same flame is converted to gas. A low amount of vitrified solid residue material usually remains at the end of this process. Plasma pyrolysis/vitrification (PP/V) has been demonstrated as a safe, efficient, cost-effective technology for the treatment of wastes, including hazardous wastes. Besides the low amounts of gaseous byproducts that PP/V produces, the solid vitrified residue presents a low leachability of pollutants. Studies have been performed in many countries in order to assess the leachability of chemical substances. But from the results of identified studies, none has reported results on the ecotoxicological properties of the leachates. The aim of this study was to contribute to the assessment of ecotoxic risk of four different vitrified materials. Vitrified samples of contaminated soils, municipal solid wastes, and incinerator bottom ashes were submitted to the European leaching pre-standard test number prEN 12457-2. The leachates were analyzed for 22 chemical parameters. The biological characterization comprised the assessment of bioluminescence inhibition of Photobacterium phosphoreum bacterium, growth inhibition of Pseudokirchneriella subcapitata algae and the germination inhibition of Lactuca sativa vegetable. The chemical and ecotoxicological results were analyzed according to the French proposal of Criteria on the Evaluation Methods of Waste Toxicity (CEMWT) and a Toxicity Classification System (TCS). The chemical and ecotoxicological results indicated a low leachability of pollutants and a low toxicity level of leachates. All samples studied were as below the TCS class 1 level (no significant toxicity observed) and as non-ecotoxic for CEMWT. Therefore, the environmental ecotoxic risk of the analyzed vitrified samples was determined to be very low.     

A comparative study for results obtained using biomonitors and PM10 collectors in Sado Estuary

In 1996 a program was started, financed by the Environmental Ministry of Portugal and IAEA, aiming to study the inorganic atmospheric pollutant dispersion in Sado Estuary. Gent PM10 air samplers were used for air particulate matter sampling. Three sampling sites were chosen, forming a triangle around the fuel power station of Setúbal. Transplants of Parmelia sulcata Taylor were suspended in nylon bags within a rectangle 15 km wide and 25 km long on a 2.5 x 2.5 km grid. Two sets of four transplants were hung in each of the 47 locations, one set facing the wind and the other set opposing the wind. The transplants were suspended in December 1997 for a 1-year period; every 3 months, one transplant of each set was collected. Both lichen transplants and PM10 filters were analysed by INAA and PIXE. A comparative study of results obtained for the two sampling procedures is presented in this work.     

Seasonal patterns in the orientation system of the migratory ant Pachycondyla marginata

Route directions of migrations by the neotropical termite-hunting ant Pachycondyla marginata at a forest reserve in Southeast Brazil were analysed by circular statistic. Colony movement patterns were compared between the rainy/hot and dry/cold seasons. Migrations during the dry/cold season are significantly oriented 13 degrees with the magnetic North-South axis, while rainy/hot migrations do not exhibit a preferred direction. This result is discussed considering the hypothesis that P. marginata ants may use the geomagnetic field as an orientation cue for migrations in the dry/cold season. The presence of magnetic iron oxides in the head and abdomen of P. marginata is consistent with this suggestion.