Effect of buffer strips and soil texture on runoff losses of flufenacet and isoxaflutole from maize fields

The influence of buffer strips and soil texture on runoff of flufenacet and isoxaflutole was studied for two years in Northern Italy. The efficacy of buffer strips was evaluated on six plots characterized by different soil textures; two plots had Riva soil (18.6% sand, 63.1% silt, 18.3% clay) while the remaining four plots had Tetto Frati (TF) soil (37.1% sand, 57% silt, 5.9% clay). Additionally, the width of the buffer strips, constituted of spontaneous vegetation grown after crop sowing, was also compared for their ability to abate runoff waters. Chemical residues in water following runoff events were investigated, as well as their dissipation in the soil. After the first runoff events, concentrations of herbicides in water samples collected from Riva plots were as much as four times lower in waters from TF plots. On average of two growing seasons, the field half-life of flufenacet in the upper soil layer (5 cm) ranged between 8.1 and 12.8 days in Riva soil, 8.5 and 9.3 days in TF soil. Isoxaflutole field half-life was less than 1 day. The buffer strip was very affective by the uniformity of the vegetative cover, particularly, at the beginning of the season. In TF plots, concentration differences were generally due to the presence or absence of the buffer strip, regardless of its width.     

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.     

Spatial distribution and partitioning of polychlorinated biphenyl and organochlorine pesticide in water and sediment from Sarno River and Estuary,Southern Italy

The Sarno River is nicknamed “the most polluted river in Europe”. The main goal of this study is to enhance our knowledge on the Sarno River water and sediment quality and on its environmental impact on the gulf of Naples (Tyrrhenian Sea, Central Mediterranean Sea) in order to become a useful assessment tool for the regional administrations. For these reasons, 32 selected polychlorinated biphenyls (PCBs) and aldrin, α-BHC, β-BHC, δ-BHC, γ-BHC (lindane), 4,4′-DDD, 4,4′-DDE, 4,4′-DDT, dieldrin, endosulfan I, endosulfan II, endosulfan sulphate, endrin, endrin aldehyde, heptachlor, heptachlor epoxide (isomer B) and methoxychlor were determined in the water dissolved phase (DP), suspended particulate matter (SPM) and sediments. Total concentrations of PCBs ranged from 1.4 to 24.9 ng L^?1 in water (sum of DP and SPM) and from 1.01 to 42.54 ng g^?1 in sediment samples. The concentrations of total organochlorine pesticides (OCPs) obtained in water (sum of DP and SPM) ranged from 0.54 to 7.32 ng L^?1 and from 0.08 to 5.99 ng g^?1 in sediment samples. Contaminant discharges of PCBs and OCPs into the sea were calculated in about 1,247 g day^?1 (948 g day^?1 of PCBs and 326 g day^?1 of OCPs), showing that this river should account as one of the main contribution sources of PCBs and OCPs to the Tyrrhenian Sea.     

Exposure to cadmium in male urban and rural workers and effects on FSH,LH and testosterone

ObjectiveThis cross-sectional study was conducted to assess the relationship between exposure to cadmium and circulating reproductive hormone levels in urban and rural male workers.Materials and MethodsUrinary cadmium, blood cadmium, luteinizing hormone (LH), follicle stimulating hormone (FSH) and testosterone were obtained from 86 non-smoking traffic policemen and 86 subjects working as roadmen in a rural area. All subjects were monitored to evaluate airborne exposure to cadmium.ResultsThe mean value of exposure to cadmium was 1.3 ng m^?3 in traffic policemen, while the mean value was less than 0.5 ng m^?3 in roadmen. The mean concentrations of urinary cadmium (1.4 vs. 0.9 μg g^?1 creatinine; p = 0.001), blood cadmium (1.1 vs. 0.7 μg l^?1; p = 0.000), FSH (2.6 vs. 3.2 μlU ml^?1; p = 0.02) and LH (2.6 vs. 3.1 μlU ml^?1; p = 0.03) were significantly different between traffic policemen and roadmen. No differences were found in the mean values of testosterone between the two groups. Multiple linear regression models showed associations between (a) urinary cadmium, airborne cadmium, working life, job category and consumption of water from water supply (b) blood cadmium, airborne cadmium and job category (c) the values of FSH and age, working life, job category, urinary cadmium and blood cadmium (d) the values of LH and both the age and working life.ConclusionThe above results must be confirmed by further studies, but they indicate the influence of exposure to the cadmium present in urban air on the circulating FSH, even at low doses.     

Abnormal amniotic fluid levels of CA 125 in second-trimester Down syndrome pregnancies

The aim of this study was to evaluate the concentration of CA 125 in second trimester amniotic fluid from Down syndrome pregnancies. CA 125 was measured in stored amniotic fluid samples from pregnancies of 14–19 weeks' gestation with and without Down syndrome fetuses. CA 125 levels were expressed in multiples of the median (MOM) for normal pregnancies of the same gestational age. Twenty-one pregnancies with Down syndrome fetuses and 63 unaffected controls matched for maternal age, gestational age, and duration of storage were studied. The median MOM values of the affected pregnancies were significantly higher than those of the controls (1·41 MOM versus 0·99 MOM). These findings show that there is an increased concentration of CA 125 in second-trimester amniotic fluid from Down syndrome pregnancies.     

Detection of a Toxic Product Released by a Polyurethane-Containing Film Using a Composting Test Method Based on a Mineral Bed

The degradation of a film containing a 4,4diphenyl methane diisocyanate (MDI) poly(€-caprolactone)-based polyurethane was followed in a test system based on a mineral solid bed designed to facilitate analysis of break-down products released under composting conditions. The use of a mineral solid bed can help extraction and analytical procedures which could be hindered by the heterogeneous nature of compost. The fermentation conditions are typical of the composting environment and generate a powerfully degradative environment. The film fully disintegrated within 30 days of treatment. Analysis on the mineral bed extracts showed that: (i) about 40% of the initial polyurethane was still present in the bed extracts; (ii) this residue was strongly degraded in the poly(€-caprolactone) part, while the urethane part was almost completely recovered (from 80 to 95%, according to the measurement method); (iii) 4,4 diamino diphenyl methane (MDA), a very dangerous product of MDI, was released during biodegradation. The results indicate that a mineral bed can be employed to study degradation and metabolites formation in solid phase fermentation and that the MDI-based polyurethanes are not susceptible of a full degradation during composting and maintain the potential of a slow release of MDA into the environment after soil application.     

Modelling of the acid-base properties of natural and synthetic adsorbent materials used for heavy metal removal from aqueous solutions

In this paper a comparison about kinetic behaviour, acid-base properties and copper removal capacities was carried out between two different adsorbent materials used for heavy metal removal from aqueous solutions: an aminodiacetic chelating resin as commercial product (Lewatit TP207) and a lyophilised bacterial biomass of Sphaerotilus natans. The acid-base properties of a S. natans cell suspension were well described by simplified mechanistic models without electrostatic corrections considering two kinds of weakly acidic active sites. In particular the introduction of two-peak distribution function for the proton affinity constants allows a better representation of the experimental data reproducing the site heterogeneity. A priori knowledge about resin functional groups (aminodiacetic groups) is the base for preliminary simulations of titration curve assuming a Donnan gel structure for the resin phase considered as a concentrated aqueous solution of aminodiacetic acid (ADA). Departures from experimental and simulated data can be interpreted by considering the heterogeneity of the functional groups and the effect of ionic concentration in the resin phase. Two-site continuous model describes adequately the experimental data. Moreover the values of apparent protonation constants (as adjustable parameters found by non-linear regression) are very near to the apparent constants evaluated by a Donnan model assuming the intrinsic constants in resin phase equal to the equilibrium constants in aqueous solution of ADA and considering the amphoteric nature of active sites for the evaluation of counter-ion concentration in the resin phase. Copper removal outlined the strong affinity of the active groups of the resin for this ion in solution compared to the S. natans biomass according to the complexation constants between aminodiacetic and mono-carboxylic groups and copper ions.