Simulating the fate of indigenous antibiotic resistant bacteria in a mild slope wastewater polluted stream

The fate of indigenous surface-water and wastewater antibiotic resistant bacteria in a mild slope stream simulated through a hydraulic channel was investigated in outdoor experiments.The effect of(i) natural(dark) decay,(ii) sunlight,(iii) cloudy cover,(iv) adsorption to the sediment,(v) hydraulic conditions,(vi) discharge of urban wastewater treatment plant(UWTP)effluent and(vii) bacterial species(presumptive Escherichia coli and enterococci) was evaluated.Half-life time(T1/2) of E. coli under sunlight was in the range 6.48–27.7 min(initial bacterial concentration of 10~5 CFU/mL) depending on hydraulic and sunlight conditions. E. coli inactivation was quite similar in sunny and cloudy day experiments in the early 2 hr, despite of the light intensity gradient was in the range of 15–59 W/m~2; but subsequently the inactivation rate decreased in the cloudy day experiment(T1/2= 23.0 min) compared to sunny day(T_(1/2)= 17.4 min). The adsorption of bacterial cells to the sediment(biofilm) increased in the first hour and then was quite stable for the remaining experimental time. Finally, when the discharge of an UWTP effluent in the stream was simulated, the proportion of indigenous antibiotic resistant E. coli and enterococci was found to increase as the exposure time increased, thus showing a higher resistance to solar inactivation compared to the respective total populations.     

Toxic effects of the ingestion of water-soluble elements found in soil under the atmospheric influence of an industrial complex

In this study, we investigated the toxic effects of water-soluble elements from a contaminated soil via gavage in a single dose, simulating a geophagy event. The contaminated soil was collected in a field located in an industrial complex, and the control soil was collected in a reference area. Metabolic and behavioral parameters in Wistar male rats were measured after 24 and 96 h of gavage. After 96 h, the major organs were weighed, blood was collected to check hematological parameters, the bone marrow was taken for the micronucleus test, and the liver was used for evaluating the total antioxidant capacity, lipoperoxidation and protein carbonylation. Animals exposed to contaminated soil presented a few significant alterations by comparison with control animals: TBARS and protein carbonyl levels increased, the relative weight of the kidneys increased, metabolic parameters (body weight gain, food intake, water consumption, urine and feces production) depressed and there was behavioral alteration. These findings suggest that soils impacted by atmospheric contaminants can affect the organism physiological status jeopardizing the health of populations living in industrial areas. Finally, this study reassures that ingestion of potentially contaminated soils, even for short periods of time, can cause health risks.     

Impacts of past and future land changes on landslides in southern Italy

Regional Environmental Change - Land use and land cover (LULC), as well as their geographical and temporal variations, affect landslide occurrence and the related risk, in ways that are difficult...     

Olive mill solid residues as heavy metal sorbent material: a preliminary study

Biosorption of heavy metals is an innovative and alternative technology to remove these pollutants from aqueous solutions using inactive and dead biomasses such as agricultural and industrial wastes, algae and bacteria. In this study olive mill solid residue was used as heavy metal adsorbent material for its wide availability as agricultural waste and also for its cellulosic matrix, rich of potential metal binding active sites. Preliminary studies concerned with the removal of different heavy metals (Hg, Pb, Cu, Zn and Cd), the effect of pre-treatments by water and n-hexane and the regeneration possibility. Olive mill solid residue resulted able to remove heavy metals from aqueous solutions with an affinity series reflecting the hydrolytic properties of the metallic ions, but also a particular affinity for copper. It can be supposed that biosorption phenomenon occur by a general ion exchange mechanism combined with a specific complexation reaction for copper ions. Water pre-treatment is sufficient to reduce COD release in the effluent according to the law limit, while n-hexane pre-treatment strongly reduces also the adsorption properties of this material. Experimental isotherms obtained under different operating conditions were fitted using a non linear regression method for the estimation of the Langmuir parameters. Moreover a simple Scatchard plot analysis was performed for a preliminary investigation of the active sites, showing the presence of two different site affinities depending on the metal concentration, according to the previous hypothesis of two kinds of uptake mechanisms for copper biosorption. Regeneration tests gave good results in terms of yield of regeneration and also concentration ratios.     

Environmental distribution of uranium and other trace elements at selected Kosovo sites

This paper reports the results of a study using lichens as biomonitors to investigate the environmental distribution of uranium and other trace elements at selected Kosovo sites. The results suggested that the use of depleted uranium (DU) ammunitions in Kosovo did not cause a diffuse environmental contamination in such a way to have caused a detectable U enrichment in lichens. Also isotopic (235)U/(238)U measurements did not indicate the presence of DU particles in lichens. The present results also provided no indication of intense environmental contamination by the other trace elements analyzed, with the exception of Kosovska Mitrovica, where a diffuse environmental contamination by several heavy elements such as Pb, Zn, As and Cd was found.     

Differentiating the effects of climate and land use change on European biodiversity: A scenario analysis

Current observed as well as projected changes in biodiversity are the result of multiple interacting factors, with land use and climate change often marked as most important drivers. We aimed to disentangle the separate impacts of these two for sets of vascular plant, bird, butterfly and dragonfly species listed as characteristic for European dry grasslands and wetlands, two habitats of high and threatened biodiversity. We combined articulations of the four frequently used SRES climate scenarios and associated land use change projections for 2030, and assessed their impact on population trends in species (i.e. whether they would probably be declining, stable or increasing). We used the BIOSCORE database tool, which allows assessment of the effects of a range of environmental pressures including climate change as well as land use change. We updated the species lists included in this tool for our two habitat types. We projected species change for two spatial scales: the EU27 covering most of Europe, and the more restricted biogeographic region of ‘Continental Europe’. Other environmental pressures modelled for the four scenarios than land use and climate change generally did not explain a significant part of the variance in species richness change. Changes in characteristic bird and dragonfly species were least pronounced. Land use change was the most important driver for vascular plants in both habitats and spatial scales, leading to a decline in 50–100% of the species included, whereas climate change was more important for wetland dragonflies and birds (40–50 %). Patterns of species decline were similar in continental Europe and the EU27 for wetlands but differed for dry grasslands, where a substantially lower proportion of butterflies and birds declined in continental Europe, and 50 % of bird species increased, probably linked to a projected increase in semi-natural vegetation. In line with the literature using climate envelope models, we found little divergence among the four scenarios. Our findings suggest targeted policies depending on habitat and species group. These are, for dry grasslands, to reduce land use change or its effects and to enhance connectivity, and for wetlands to mitigate climate change effects.