Planning routes around the world: International evidence for southern route preferences

Three studies test whether the southern route preference, which describes the tendency for route planners to disproportionately select south- rather than north-going routes, can be attributed to regional elevation patterns; specifically, we ask whether this effect replicates in three topographically disparate international regions, one of which is characterized by higher elevations to the north and lower to the south (Padua, Italy), and two characterized by higher elevations to the south and lower to the north (Enschede, Netherlands; Sofia, Bulgaria). In all cases, we found strong evidence that route planners disproportionately select south- rather than north-going routes at rates exceeding chance. We conclude that the southern route preference is driven by strong associations between canonical direction and perceived effort of route traversal; these effects are somewhat perplexing given that such associations are not founded in the reality of physical space.     

Stream water chemistry in the arsenic-contaminated Baccu Locci mine watershed (Sardinia, Italy) after remediation

The abandoned Pb–As Baccu Locci mine represents the first and only case of mine site remediation in Sardinia, Italy. Arsenic is the most relevant environmental concern in the Baccu Locci stream watershed, with concentrations in surface waters up to and sometimes over 1 mg/L. The main remediation action consisted in creation of a “storage site”, for the collection of contaminated materials from different waste-rock dumps and most of tailings piles occurring along the Baccu Locci stream. This paper reports preliminary results on the level of contamination in the Baccu Locci stream after the completion of remediation measures. Post-remediation stream water chemistry has not substantially changed compared to the pre-remediation situation. In particular, dissolved As maintains an increasing trend along the Baccu Locci stream, with a concentration of about 400 μg/L measured at a distance of 7 km from the storage site. Future monitoring will provide fundamental information on the effectiveness of remediation actions conducted and their applicability to other mine sites in Sardinia. At the stage of mine site characterisation of future remediation plans, it is recommended to pay more attention to the understanding of mineralogical and geochemical processes responsible for pollution. Moreover, mixing of materials with different composition and reactivity in a storage site should require careful consideration and long-term leaching tests.     

Development and application of a regional-scale atmospheric mercury model based on WRF/Chem: a Mediterranean area investigation

The emission, transport, deposition and eventual fate of mercury (Hg) in the Mediterranean area has been studied using a modified version of the Weather Research and Forecasting model coupled with Chemistry (WRF/Chem). This model version has been developed specifically with the aim to simulate the atmospheric processes determining atmospheric Hg emissions, concentrations and deposition online at high spatial resolution. For this purpose, the gas phase chemistry of Hg and a parametrised representation of atmospheric Hg aqueous chemistry have been added to the regional acid deposition model version 2 chemical mechanism in WRF/Chem. Anthropogenic mercury emissions from the Arctic Monitoring and Assessment Programme included in the emissions preprocessor, mercury evasion from the sea surface and Hg released from biomass burning have also been included. Dry and wet deposition processes for Hg have been implemented. The model has been tested for the whole of 2009 using measurements of total gaseous mercury from the European Monitoring and Evaluation Programme monitoring network. Speciated measurement data of atmospheric elemental Hg, gaseous oxidised Hg and Hg associated with particulate matter, from a Mediterranean oceanographic campaign (June 2009), has permitted the model’s ability to simulate the atmospheric redox chemistry of Hg to be assessed. The model results highlight the importance of both the boundary conditions employed and the accuracy of the mercury speciation in the emission database. The model has permitted the reevaluation of the deposition to, and the emission from, the Mediterranean Sea. In light of the well-known high concentrations of methylmercury in a number of Mediterranean fish species, this information is important in establishing the mass balance of Hg for the Mediterranean Sea. The model results support the idea that the Mediterranean Sea is a net source of Hg to the atmosphere and suggest that the net flux is ≈30 Mg year^?1 of elemental Hg.     

Metal contamination in urban street sediment in Pisa (Italy) can affect the production of antioxidant metabolites in Taraxacum officinale Weber

Taraxacum officinale Weber (dandelion) is a very ubiquitous species, and it can grow in urban environments on metal-polluted sediments deposited in the gutters. This study represents a preliminary step to verify the presence of metals in sediments collected in urban streets in Pisa and to assess the alteration in dandelion metabolites in order to understand its adaptation to polluted environments. The soil and sediments were collected at three urban streets and analyzed for total and extractable Cr, Pb, Cu, Ni, and Zn. The total values of Pb and Zn in street sediments exceeded the limits for residential areas of soils. Zn was the most mobile of the metals analyzed. Floating cultivations trials were set up with dandelion seedlings and street sediments. The metals were analyzed in roots and leaves. Antioxidant power, anthocyanins, polyphenols, non-protein thiols (NP-TH) and chlorophylls were measured in dandelion leaves. The first two parameters (anthocyanins and antioxidant power) were higher in the polluted samples compared to the control; chlorophyll content was lower in the treated samples, whereas NP-TH showed no differences. NP-TH groups determined in roots were associated with the root content of Zn and Pb. These results indicate that dandelion can tolerate plant stress by altering its metabolite content.     

Mercury in the Mediterranean,part I: spatial and temporal trends

The present paper provides an overview of mercury studies performed in the Mediterranean Sea region in the framework of several research projects funded by the European Commission and on-going national programmes carried out during the last 15 years. These studies investigated the temporal and spatial distribution of mercury species in air, in the water column and sediments, and the transport mechanisms connecting them. It was found that atmospheric concentrations of Hg compounds, particularly oxidised Hg species observed at five coastal sites in the Mediterranean Sea Basin, are significantly higher compared with those recorded at five coastal sites distributed across N Europe, most probably due to natural emissions. Hg levels in water are comparable to other oceans. Anthropogenic and natural point sources show locally limited enrichments, while natural diffusive sources influence Hg speciation over larger areas. Results and statistic comparison of mercury species concentrations within Mediterranean compartments will be presented and discussed.     

Arsenate tolerance in Silene paradoxa does not rely on phytochelatin-dependent sequestration

Arsenate tolerance, As accumulation and As-induced phytochelatin accumulation were compared in populations of Silene paradoxa, one from a mine site enriched in As, Cu and Zn, the other from an uncontaminated site. The mine population was significantly more arsenate-tolerant. Arsenate uptake and root-to-shoot transport were slightly but significantly higher in the non-mine plants. The difference in uptake was quantitatively insufficient to explain the difference in tolerance between the populations. As accumulation in the roots was similar in both populations, but the mine plants accumulated much less phytochelatins than the non-mine plants. The mean phytochelatin chain length, however, was higher in the mine population, possibly due to a constitutively lower cellular glutathione level. It is argued that the mine plants must possess an arsenic detoxification mechanism other than arsenate reduction and subsequent phytochelatin-based sequestration. This alternative mechanism might explain at least some part of the superior tolerance in the mine plants.     

Integrating methods for the environmental sustainability: the SPIn-Eco Project in the Province of Siena (Italy)

This paper shows how different methods can be integrated in order to provide an organic evaluation of the environmental sustainability at the territorial level. A territory is a complex, dynamic and open system where a population develops, uses resources, produces goods and services, consumes, depletes and finally obtains economic results. All these elements characterise human behaviour, which can be monitored, measured and compared to the capacity of the environment to sustain it in the long run. The SPIn-Eco Project for the Province of Siena (Italy) is described as an example of an environmental sustainability assessment of an area, and its methods (Ecological Footprint, Greenhouse Gas Inventory, Extended Exergy Analysis, Emergy Evaluation, Life Cycle Assessment (LCA) and Remote Sensing) are briefly introduced. This Project has been proposed and funded by the most important provincial administrative and financial institutions in the territory (the Administration of the Province of Siena and the Monte dei Paschi Foundation, respectively), and was designed and realised in 4 years (2001-2004) by a research team coordinated by the University of Siena.     

Results of the monitoring program of pesticide residues in organic food of plant origin in Lombardy (Italy)

Organic agriculture, with its restrictions on the use of synthetic chemical inputs, seems to offer a low-residue alternative to conventional methods. In Europe, the Council Regulation n. 2092/91/EEC regulates the production and trade of organic products and foodstuffs; national and regional legislation in Italy gives specific guidance on the surveillance of organic agriculture. However, monitoring of specific chemical residues in organic foodstuffs is part of the regular controls on food, aiming to safeguard consumer's health. Monitoring programs are coordinated at the national level by the Ministry of Health and at local level by Regional authorities. In Lombardy, in accordance with the provisions of the General Directorate of Health of the Region and under the supervision of the 15 Local Health Units, a monitoring program of pesticide residues in food of plant origin is undertaken every year. The International Centre for Pesticides and Health Risk Prevention (ICPS), on behalf of the General Directorate of Health of the Region of Lombardy, has been collecting and elaborating the data resulting from the analysis of food samples, carried out by the local laboratories. During the period 2002-2005, a total of 3508 samples food of plant origin were analyzed for pesticide residues, among which were 266 samples of organic farming products. Commodities were classified into groups (citrus fruits, legumes, vegetables, potatoes, processed products, cereals, and fruit other than citrus) and the outcomes of the analyses were reported by year, origin of the sample and presence/absence of pesticide residues. Results showed that the vast majority of organic farming products were in conformity with the relevant legislation and did not contain detectable pesticide residues. A limited amount of samples had residues at concentration below the Maximum Residue Limit (MRL). Only in one sample the residue level was above the MRL, however it did not pose a concern for public health, as demonstrated by the outcomes of dietary risk assessment. Organic fruits and vegetables can be expected to contain fewer agrochemical residues than conventionally grown alternatives. There is a widespread belief that organic agriculture products are safer and healthier than conventional foods. It is difficult to come to conclusions, but what should be made clear to the consumer is that "organic" does not automatically equal "safe". In the absence of adequate comparative data, additional studies in this area of research are required.     

Analysis of short-chain chlorinated paraffins: a discussion paper

Short-chain chlorinated paraffins are a class of organic compounds widely used in many industrial applications, extensively diffused into the environment, persistent, bioaccumulative, and toxic towards aquatic organisms. However, their study and monitoring in the environment are still limited. Because of the enormous number of positional isomers that characterise their mixtures, the analysis of this class of pollutants is very difficult to perform. Beside this, the lack of certified reference materials poses a problem for the assessment of the quality assurance/quality control of any analytical procedure. At present, the scientific community does not agree on any analytical reference method, although the monitoring of short-chain chlorinated paraffins has already started in order to comply with the Water Framework Directive of the European Union on water quality. In this paper the regulatory framework, in which chlorinated paraffins are included, and the status concerning their determination are summarized. The main analytical difficulties still existing are discussed, and the definition of a method-defined parameter as well as the development of a standardised method are suggested as a way to obtain comparable monitoring data.     

Use of sulfadimethoxine in intensive calf farming: evaluation of transfer to stable manure and soil

After prophylactic treatment of 50 calves with 62mgkg(-1)day(-1) of sulfadimethoxine (SDM) for five days, the levels of the drug over time were followed in feces, bedding and stable manure, and then in the soil of a manured field and surrounding drainage courses. Analysis were done by HPLC after applying to the different matrices a quick and simple extraction procedure. The half-life of the drug in bedding was very short (24h). In stable manure the degradation rate of the drug slowed down and the calculated half-life was 64 days, with 390microgkg(-1) of SDM still detectable after three months maturation. However, in a five months matured stable manure obtained from other groups of calves subjected to the same prophylactic treatment, levels of SDM were <50muicrokg(-1) (LOD of the analytical method). After field fertilization with this manure, no traces of SDM were found in soil (LOD 10microgkg(-1)) or in the water (LOD 2microgl(-1)) from the surrounding drainage courses. Using the internationally recognised DAPHTOXKIT-Ftrade mark, a SDM toxicity test toward Daphnia magna was performed in the range 10-100mgl(-1). The test gave negative results both after 24 and 48h, confirming that microcrustaceans are less sensitive than other models to the toxicity of antibacterials. However, based on data from other authors, concerning algal toxicity and microbial inhibition, and on the analytical results from the current field study, the calculated worst-case EC50/PEC ratio for SDM both in freshwater and in soil was still >1000.