Phytomanagement of strongly acidic,saline eutrophic wetlands polluted by mine wastes: The influence of liming and Sarcocornia fruticosa on metals mobility

The aim of this study was to assess the effectiveness of combining liming and vegetation for the phytomanagement of strongly acidic, saline eutrophic wetlands polluted by mine wastes. Simulated soil profiles were constructed and four treatments were assayed: without liming + without plant, without liming + with plant, with liming + without plant and with liming + with plant. The plant species was the halophyte Sarcocornia fruticosa. Three horizons were differentiated: A (never under water), C1 (alternating flooding–drying conditions) and C2 (always under water). The soluble Cd, Cu, Mn, Pb and Zn concentrations were measured regularly for 18 weeks and a sequential extraction procedure was applied at the end of the experiment. Liming was effective (between ～70% and ～100%) in reducing the soluble Zn, Cu and Pb. In contrast, soluble Mn and Cd increased with liming, especially in the treatment with liming + with plant, where the concentrations were 2-fold higher than in the non-limed treatments. The amendment increased the contents of Zn, Mn and Cd bound to potentially-mobilisable soil fractions at the expense of the most-environmentally-inert fractions. Hence, the combined use of liming and vegetation may increase the long-term environmental risk of metals solubilisation.     

Inhibition of the antioxidant activity of catalase and superoxide dismutase from Fusarium verticillioides exposed to a Jacquinia macrocarpa antifungal fraction

The aim of this study was to investigate the in vitro effect of an antifungal fraction obtained from Jacquinia macrocarpa plant (JmAF) in the generation of reactive oxygen species (ROS) and the activity of the catalase (CAT) and superoxide dismutase (SOD) enzymes from Fusarium verticillioides, as well as their influence in the viability of the fungus spores. The compounds present in the JmAF were determined by gas chromatography/quadrupole time-of-flight mass spectrometry (GC/QTOF-MS). The effect of the exposition to JmAF on the generation of ROS, as well as in the CAT and SOD activities in F. verticillioides, was determined. The main compounds detected were γ-sitosterol, stephamiersine, betulinol and oleic acid. JmAF showed very high ability in inhibiting the spore viability of F. verticillioides, and their capacity to cause oxidative stress by induction of ROS production. JmAF induced the highest ROS concentration and also inhibited CAT and SOD activities. The results obtained in this study indicate that JmAF is worthy of being considered for the fight against phytopathogenic fungi.     

Endosulfan acute toxicity and histomorphological alterations in Jenynsia multidentata (Anablepidae, Cyprinodontiformes)

Toxicity tests using adult specimens of Jenynsia multidentata were carried out during 96 hours in order to determine the lethal concentration (LC50) of endosulfan. Histological alterations were determined in gills and liver. Gill damage was quantified as secondary lamellae thickness. The 96 hr LC50 values were significantly different between males (0.719 microg x L(-1)) and females (1.317 microg x L(-1)). The sex difference was attributed to the dimorphism in the lipid content in females (2.16%) and males (1.79%). Histological alterations in gills included hypertrophy and lifting of the epithelium of the secondary lamellae and aneurisms. These alterations caused a significant increase of the secondary lamellae thickness in treatment versus control fish. Finally, reversible histological alterations (such as hydropic degeneration and dilation of sinusoids) were observed in the liver of exposed fish as well as an irreversible change such as necrosis at the highest concentrations.     

A new intelligent electronic nose system for measuring and analysing livestock and poultry farm odours

This paper introduces a new portable intelligent electronic nose system developed especially for measuring and analysing livestock and poultry farm odours. It can be used in both laboratory and field. The sensor array of the proposed electronic nose consists of 14 gas sensors, a humidity sensor, and a temperature sensor. The gas sensors were especially selected for the main compounds from the livestock farm odours. An expert system called “Odour Expert” was developed to support researchers’ and farmers’ decision making on odour control strategies for livestock and poultry operations. “Odour Expert” utilises several advanced artificial intelligence technologies tailored to livestock and poultry farm odours. It can provide more advanced odour analysis than existing commercially available products. In addition, a rank of odour generation factors is provided, which refines the focus of odour control research. Field experiments were conducted downwind from the barns on 14 livestock and poultry farms. Experimental results show that the predicted odour strengths by the electronic nose yield higher consistency in comparison to the perceived odour intensity by human panel. The “Odour Expert” is a useful tool for assisting farmers’ odour management practises. Supported by Ontario Pork, Natural Sciences and Engineering Research Council (NSERC), and Ontario Ministry of Agriculture and Food (OMAF) of Canada.     

Atmospheric Monitoring at Abandoned Mercury Mine Sites in Asturias (NW Spain)

Mercury concentrations are usually significant in historic Hg mining districts all over the world, so the atmospheric environment is potentially affected. In Asturias, northern Spain, past mining operations have left a legacy of ruins and Hg-rich wastes, soils and sediments in abandoned sites. Total Hg concentrations in the ambient air of these abandoned mine sites have been investigated to evaluate the impact of the Hg emissions. This paper presents the synthesis of current knowledge about atmospheric Hg contents in the area of the abandoned Hg mining and smelting works at ‘La Peña–El Terronal’ and La Soterraña, located in Mieres and Pola de Lena districts, respectively, both within the Caudal River basin. It was found that average atmospheric Hg concentrations are higher than the background level in the area (0.1 μg Nm^?3), reaching up to 203.7 μg Nm^?3 at 0.2 m above the ground level, close to the old smelting chimney at El Terronal mine site. Data suggest that past Hg mining activities have big influences on the increased Hg concentrations around abandoned sites and that atmospheric transfer is a major pathway for Hg cycling in these environments.     

PM sources in a highly industrialised area in the process of implementing PM abatement technology. Quantification and evolution

Principal component analysis (PCA) coupled with a multilinear regression analysis (MLRA) was applied to PM(10) speciation data series (2002-2005) from four sampling sites in a highly industrialised area (ceramic production) in the process of implementing emission abatement technology. Five common factors with similar chemical profiles were identified at all the sites: mineral, regional background (influenced by the industrial estate located on the coast: an oil refinery and a power plant), sea spray, industrial 1 (manufacture and use of glaze components, including frit fusion) and road traffic. The contribution of the regional background differs slightly from site to site. The mineral factor, attributed to the sum of several sources (mainly the ceramic industry, but also with minor contributions from soil resuspension and African dust outbreaks) contributes between 9 and 11 microg m(-3) at all the sites. Source industrial 1 entails an increase in PM(10) levels between 4 and 5 microg m(-3) at the urban sites and 2 microg m(-3) at the suburban background site. However, after 2004, this source contributed less than 2 microg m(-3) at most sites, whereas the remaining sources did not show an upward or downward trend along the study period. This gradual decrease in the contribution of source industrial 1 coincides with the implementation of PM abatement technology in the frit fusion kilns of the area. This relationship enables us to assess the efficiency of the implementation of environmental technologies in terms of their impact on air quality.     

Reactivity, interactions and transport of trace elements, organic carbon and particulate material in a mountain range river system (Adour River, France)

The background levels, variability, partitioning and transport of eleven trace elements-Ag, Al, As, Cd, Co, Cr, Cu, Mn, Pb, Zn and U-were investigated in a mountain range river system (Adour River, France). This particular river system displayed a turbulent hydrodynamic regime, characterized by flash-transient discharge conditions leading to fast shifts in suspended particulate matter (SPM) concentrations as high as two orders of magnitude (12 to 600 mg l(-1)). The distribution of SPM was accurately predicted with a "hysteresis" transport model, indicating that about 75% of the annual solids load was exported within 20 to 40 days. Dissolved and particulate concentrations of most trace elements were low compared to their concentrations in other reference river systems expect for Pb and Cr, associated with historical anthropogenic activities. Although dissolved and particulate metal concentrations were steady for most elements during low and average discharge conditions, significant changes were observed with increasing river discharge. The changes in trace element concentrations in the two compartments was found to induce a partitioning anomaly referred to as the particulate concentration effect. This anomaly was significant for Cr, Mn, Pb, Zn, Cu and organic carbon (p < 0.03). The processes driving this anomaly were possibly linked to the modification and/or increase of colloidal organic and inorganic vectors, suggested by the significant increase of DOC (p < 0.001) and dissolved Al concentrations (p < 0.05) during flood conditions. A complementary process linked to the influence of coarse particles of low complexation capacity and transported mainly during high discharge may also effect trace element concentrations. Annual metal fluxes transported by this river system were estimated using the hysteresis SPM model with consideration of these fate processes. Metals in the Adour River system are primarily exported into the Bay of Biscay (Atlantic Ocean).     

A review of ozone-induced effects on the forests of central Mexico

The first report on oxidant-induced plant damage in the Valley of Mexico was presented over 30 years ago. Ozone is known to occur in the Mexico City Metropolitan Area and elsewhere as the cause of chlorotic mottling on pine needles that are 2 years old or older as observed in 1976 on Pinus hartwegii and Pinus leiophylla. Visible evidences for the negative effects of ozone on the vegetation of central Mexico include foliar injury expressed as chlorotic mottling and premature defoliation on pines, a general decline of sacred fir, visible symptoms on native forest broadleaved species (e.g. Mexican black cherry). Recent investigations have also indicated that indirect effects are occurring such as limited root colonization by symbiotic fungi on ozone-damaged P. hartwegii trees and a negative influence of the pollutant on the natural regeneration of this species. The negative ozone-induced effects on the vegetation will most likely continue to increase.     

Genotoxicity assessment of soils from wastewater irrigation areas and bioremediation sites using the Vicia faba root tip micronucleus assay

Genotoxicity potential of soils taken from wastewater irrigation areas and bioremediation sites was assessed using the Vicia faba root tip micronucleus assay. Twenty five soils were tested, of which 8 were uncontaminated soils and taken as the control to examine the influence of soil properties; 6 soils were obtained from paddy rice fields with a history of long-term wastewater irrigation; 6 soils were obtained from bioremediation sites to examine effects of bioremediation; and 5 PAH-contaminated soils were used to examine methodological effects between direct soil exposure and exposure to aqueous soil extracts on micronuclei (MN) frequency ( per thousand) in the V. faba root tips. Results indicate that soil properties had no significant influences on MN frequencies (p > 0.05) when soil pH varied between 3.4 to 7.6 and organic carbon between 0.4% and 18.6%. The MN frequency measured in these control soils ranged from 1.6 per thousand to 5.8 per thousand. MN frequencies in soils from wastewater irrigation areas showed 2- to 48-fold increase as compared with the control. Soils from bioremediation sites showed a mixed picture: MN frequencies in some soils decreased after bioremediation, possibly due to detoxification; whereas in other cases remediated soils induced higher MN frequencies, suggesting that genotoxic substances might be produced during bioremediation. Exposure to aqueous soil extracts gave a higher MN frequency than direct exposure in 3 soils. However, the opposite was observed in the other two soils, suggesting that both exposure routes should be tested in case of negative results from one route. Data obtained from this study indicate that the MN assay is a sensitive assay suitable for evaluating genotoxicity of soils.     

Environmental assessment of water-courses of the Turvo Limpo River basin at the Minas Gerais State, Brazil

A study was performed to evaluate the environmental contamination in the Turvo Limpo River basin which receives effluent discharges from domestic (residential and commercial) activities. The watercourses examined were the São Bartolomeu Stream, Turvo Sujo River, and Turvo Limpo River, located in the Minas Gerais State, Brazil. Water samples were collected at the river-side and analyzed for evaluation of pollutant inputs. The pH, temperature, electrical conductivity, redox potential (Eh), dissolved oxygen (DO), total and settleable solids, visual color, hardness, chemical oxygen demand (COD), biochemical oxygen demand (BOD), chloride, total phosphate, total nitrogen, ammonia nitrogen, nitrate, total coliforms and E. coli, as well as the Cd, Pb, Cu, and Zn speciation were determined in the watercourses. The data obtained were compared with those of the Brazilian Environmental Standards and with data from non-contaminated areas. River water characteristics in some sites were far from the limit values established for superficial waters with satisfactory quality. For instance, the BOD values reached 411 mg L^?1 for a maximum limit of 10.0 mg L^?1, while the ammonia nitrogen concentration reached 28 mg L^?1 for a maximum limit of 13.3 mg L^?1. Some sites showed E. coli values above those of non-contaminated regions. Besides the effects of sewage discharges into the water-courses, agriculture activities and the use of the area for cattle husbandry influenced the quality of the river waters, for instance, the pH of a spring-water sample reached the value of 4.3. The São Bartolomeu Stream has been contributing to the deterioration of the water quality of the Turvo Sujo River, while the Turvo Limpo River has also been affected by anthropogenic discharges in the Turvo Sujo River. The speciation of Cd, Cu and Pb showed that these metals were mainly found in the particulate fraction (i. e., associated with the suspended material). Fifty five percent of the water samples showed labile Zn concentrations greater than that of the nonlabile Zn.