Higher-tier assessment of the potential for groundwater issues due to the use of 1,3-D soil fumigant; evaluation of the active ingredient, metabolites and potentially related chlorinated compounds

BACKGROUND: 1,3‐Dichloropropene (1,3‐D, CAS No. 542‐75‐6) is a broad‐spectrum soil fumigant used to control numerous species of soilborne plant‐parasitic nematodes. 1,3‐D consists of two isomers, (Z)‐ and (E)‐1,3‐D. There are a number of low‐level chlorinated compounds that could potentially be produced as a part of the 1,3‐D manufacturing process. 1,3‐D and its metabolites, as well as potentially related chlorinated compounds, represent potential groundwater contaminants. RESULTS: This study has investigated the hydrolytic stability, under biotic and abiotic conditions in the laboratory, of an extensive representative list of 1,3‐D and potentially related chlorinated compounds in order to predict their environmental fate. All of these compounds showed intrinsic hydrolytic instability under both abiotic and biotic test conditions. Furthermore, a monitoring programme was carried out. Twenty‐five wells were monitored in five Italian regions characterised by historical and existing use of 1,3‐D. The parent compound, its two major metabolites and potentially related chlorinated compounds were not detected in the well water at > 0.1 µg L^?1 at any sampling location. CONCLUSION: The soil fumigant (E,Z)‐1,3‐D, its metabolites and potentially related chlorinated compounds constitute a low risk to groundwater. Copyright © 2011 Society of Chemical Industry     

Prediction of agrochemical residue data on fruit using an informatic system (PARDIS model)

A 'step-by-step' method was used to develop a simplified procedure for calculating pesticide residue levels on fruit at harvest by considering the application of the compound and the relevant routes of loss. The model is applicable to cases where the most important exposure route is by direct spray to the canopy of the crop and where uptake into the plant by the roots can be disregarded. The exposure dose is calculated by considering the proportion of total crop cover represented by the fruits. The loss processes considered are photodegradation, uptake, volatilization and washoff.The outputs of the model were compared with measured residues of pesticides on pear. Analysis of the model fit demonstrates that the model predicted the measured data with a good level of accuracy for four of seven investigated pesticides. The predicted/observed quotients are close to 1, as is the modelling efficiency, and there are no great differences between the predicted and observed values. Taking into account the extreme simplicity of the model and the complexity of the environmental processes considered, these results encourage further research into the modelling of residue behaviour in food commodities.The objectives of this work were to produce a tool to predict pesticide residues in products of plant origin, to complement monitoring of pesticide levels and to be useful in evaluating the effect of government policies on food safety. All predicted values were below the maximum levels fixed for pesticide residues in pear, as amended in Council Directives 86/362/EEC and 90/642/EEC. Copyright (c) 2008 Society of Chemical Industry.     

Soluble carbohydrates content in tomato pollen and its variations along and between blooming periods

The soluble carbohydrates content in the mature (starchless) pollen of the tomato (Solanum lycopersicum L.) cv. Platense was studied at several moments of the blooming period in two consecutive years. The aim of the analysis was to evaluate if the content of soluble carbohydrates is relatively constant or if it can fluctuate along the blooming period. No significant variations in pollen viability were recorded along each season. The soluble carbohydrates found and their concentrations can change significantly among samples, but the fluctuations observed did not follow a strongly definite pattern in any season. Reducing sugars predominated; small quantities of a phosphorylated sugar, UDP-glucose, and maltosaccharides were also recorded. The constant presence of maltosaccharides is a novel record for pollen. Sucrose was absent in one season, but present in the other, in low percentages in contrast to reducing sugars. Changes in the soluble carbohydrates content have been usually related with alterations in pollen fertility. However, there may be some flexibility in the metabolism of the pollen studied this time, at least within a certain range, which may allow constant adjustments to maintain acceptable levels of viability despite the variations in the carbohydrates concentrations.     

Prediction of the environmental concentration of pesticide in paddy field and surrounding surface water bodies

Pesticides are very important in European rice production. For appropriate environmental protection, it is useful to predict the potential impact of pesticides after application, in paddy fields, in paddy runoff, and in the surrounding water, by calculating predicted environmental concentrations (PECs). In this paper, a joint simulation is described, coupling a field-scale pesticide fate model (RICEWQ) and a transportation model (RIVWQ) to evaluate the potential for predicting environmental concentrations of pesticides in the paddy field and adjacent surface water bodies and comparing the predicted values with the monitoring data. The results demonstrate that the application of the calibrated field-scale RICEWQ model is a conservative method to predict the PEC at the watershed level, overestimating the observed data; the coupled RICEWQ and RIVWQ models could be adequately used to predict PECs in the surrounding water at watershed level and in the higher tier risk assessment procedure.     

Fear erasure in mice requires synergy between antidepressant drugs and extinction training

Antidepressant drugs and psychotherapy combined are more effective in treating mood disorders than either treatment alone, but the neurobiological basis of this interaction is unknown. To investigate how antidepressants influence the response of mood-related systems to behavioral experience, we used a fear-conditioning and extinction paradigm in mice. Combining extinction training with chronic fluoxetine, but neither treatment alone, induced an enduring loss of conditioned fear memory in adult animals. Fluoxetine treatment increased synaptic plasticity, converted the fear memory circuitry to a more immature state, and acted through local brain-derived neurotrophic factor. Fluoxetine-induced plasticity may allow fear erasure by extinction-guided remodeling of the memory circuitry. Thus, the pharmacological effects of antidepressants need to be combined with psychological rehabilitation to reorganize networks rendered more plastic by the drug treatment.     

Towards More Efficient Incentives for Agri‐environment Measures in Degraded and Eroded Vineyards

Evaluating the economic damage caused by soil erosion is important. In addition to increasing the awareness of the problem among farmers and policy makers, evaluation of the economic damage caused by erosion can promote the implementation of more sustainable soil management practices. In the present study, we describe a new approach to evaluate incentives for the adoption of agri‐environment measure (AEM) in degraded and eroded vineyards. To estimate this incentive, the replacement cost (RC) and the loss of income are calculated when the vineyard is managed with conventional tillage versus a cover crop (AEM). Our findings show that the incentive could range from the loss of income due to AEM adoption to the ecosystem service benefit (RC_C − RC_AEM). In our case study, the incentive ranged from 315 € ha⁻¹ (loss of income) to 1,088 € ha⁻¹ (ecosystem service benefit). Within this range, the incentive amount is determined according to efficiency criteria based on vineyard slope. We also present a conceptual model of public spending efficiency that should help policy makers decide how to allocate the incentives so as to maximize the economic return associated with ecosystem services. Copyright © 2015 John Wiley & Sons, Ltd.     

Use of Red Blood Cell Membranes to Evaluate the Antioxidant Potential of Plant Extracts

Antioxidant phytochemicals in fruits and vegetables of a vegetarian diet may account for the reduced risk of aging and stress oxidative associated diseases. In this study, a simple, rapid and accurate new bioassay for the determination of the antioxidant activity of purified or crude plant extracts and thier interactions is described, based on the fluorimetric determination of thiobarbituric acid reactive substances (TBARS) released by UV-B radiated red blood cell (RBC) ghosts. Pure resveratrol, white and red wine and pomegranate juice (PJ) were used as antioxidant source to test the biological method. TBARS production is a function of radiation time, the number of RBC ghosts in the radiated sample and the loaded antioxidant. The antioxidant activity of resveratrol was detected at a submicromolar concentration range [0.02 μg/mL–0.1 μmol/L]. The activity of red wine was almost 10 times higher than that of white wine, and PJ juice had the highest activity. Submaximal protective effects of PJ and red wine were additive.     

Risk analysis of pesticides applied to rice paddies using RICEWQ 1.6.2v and RIVWQ 2.02

Rice is commonly cultivated in Southern Europe in large river basins where the extensive use of herbicides may impact water quality at basin scale level. Consequently, pesticide risk assessment would be more relevant when considering a rice cultivation area as a whole. Accordingly, two watershed-scale scenarios were developed to represent the specific agronomic, water and pesticide management practices of rice cultivation in Greece. These scenarios were utilized for the parameterization of the rice water quality model (RICEWQ) 1.6.2v and the surface water model river water quality (RIVWQ) 2.02. in order to predict the environmental concentrations of pesticides in groundwater (GW) and surface water (SW) systems within a rice area. The annual average pesticide concentrations at 1 m depth, predicted by RICEWQ were used to assess the risk for GW contamination. The predicted exposure concentrations derived through modelling and eco-toxicological endpoints obtained from the literature, were used to calculate acute and long-term toxicity exposure ratios (TERs) for aquatic organisms. Application of these scenarios with RICEWQ and RIVWQ models enabled us to perform a risk assessment exercise for several herbicides registered in Greece for use in rice. Such a risk assessment approach could be further scaled up to represent a whole rice cultivated basin in order to be used for regulatory purposes.