Uptake of heavy metals and As by Brassica juncea grown in a contaminated soil in Aznalcóllar (Spain): the effect of soil amendments

Two crops of Brassica juncea (L.) Czern. were grown in a field experiment, at the site affected by the toxic spillage of acidic, metal-rich waste in Aznalcóllar (Seville, Spain), to study its metal accumulation and the feasibility of its use for metal phytoextraction. The effects of organic soil amendments (cow manure and mature compost) and lime on biomass production and plant survival were also assessed; plots without organic amendment and without lime were used as controls. Plots, with or without organic amendment, having pH < 5 were limed for the second crop. Soil acidification conditioned plant growth and metal accumulation. The addition of lime and the organic amendments achieved higher plant biomass production, although effects concerning metal bioavailability and accumulation were masked somewhat by pH variability with time and between and within plots. Tissue metal concentrations of B. juncea were elevated for Zn, Cu and Pb, especially in leaves of plants from plots with low pH values (maxima of 2029, 71 and 55 microg g(-1), respectively). The total uptake of heavy metals in the plants was relatively low, emphasising the problems faced when attempting to employ phytoextraction for clean-up of pluri-contaminated sites.     

Predictions by the Odor From Feedlots, Setback Estimation Tool (OFFSET) compared with observations by neighborhood monitors

A comparison between predicted and observed odor intensities at 20 neighborhood residences in the vicinity of seven various livestock farms in five different Minnesota counties was made to evaluate the Odor From Feedlots, Setback Estimation Tool (OFFSET) developed by the University of Minnesota. Observations by neighborhood monitors suggest that the OFFSET-predicted separation distances for annoyance-free frequencies of 99, 98, and 97% are large enough. The observations additionally indicate that predicted distances to obtain 94 and 91% annoyance-free frequencies may be large enough for some farms, but for other farms, greater distances may be needed. For two farms in the study, no significant difference between all of the observed and predicted intensities could be found. At four sites, a significant difference was found, and at three of these the difference was considerable. Odor emission rates used in the OFFSET model seem to describe the average emission fairly well for many odor sources, but improvement may be needed for some types of sources. Possible reasons for observations of annoying odor when not predicted include fluctuations in the odor emissions, wind speed fluctuations, topographic variation between sites, sensitivity differences by neighborhood monitors, and background emissions from other sources.     

Simulation of pesticide runoff at Rosemaund Farm (UK) using the SoilFug model

A validation exercise of the SoilFug model using field runoff data from Rosemaund Farm (UK) is described. A comparison has been made of modelled and measured concentrations of several pesticides in surface water and soil during and after specific rain events following application. The field experiments were designed to obtain data on rainfall, outflows of water, pesticide application rates and concentrations in soil and water. The results were satisfactory for the undissociated pesticides (atrazine, carbofuran, dimethoate, isoproturon, lindane, simazine and trifluralin), whose concentrations in water were mostly predicted within an order of magnitude of measured data. The results for the dissociated pesticides (dichlorprop, MCPA, mecoprop) were less satisfactory, giving generally much higher predicted concentrations in water. The use of the SoilFug model is suggested for the calculation of predicted environmental concentrations (PECs) in water, since it generally produces acceptable results from a relatively small set of input data, most of which is generally available.     

Affirmative action programs: an organizational justice perspective

Affirmative Action Programs (AAPs) are becoming increasingly common in the workplace. Typically their effectiveness has been assessed by the number of women and minorities hired and promoted. A neglected, but important measure of effectiveness is how AAPs are perceived by employees. When employees perceive that AAPs violate notions of fairness, negative attitudes and behaviors may occur and lead to decreased organizational performance. A model of perceived AAP fairness is presented using an organizational justice perspective. An initial (partial) test of the model is conducted and avenues for future research are discussed.     

Threshold and dose response estimation using the “filter model”

The “filter model” has been developed to explain the biologic effects of radiation and chemicals. We have examined nearly 300 sets of dose response data, of which 50 are presented here. Responses (induced by radiation and chemicals) which have been examined include in vitro survival studies on animal and plant tissues, induction of cellular aberrations and time to tumor or death. Similar data from in vivo studies has also been examined. All of the data appear to fit the model R = a lnD + b(lnD)² + c, where R is the response, a and b are parameters fitted by regression to a particular set of data, and c is the response at zero (or lowest) dose. By writing this model in exponential form, it can be seen that the response R results from multistage filtering (by net amounts a and b) of the initial dose, D. The threshold is obtained from this model as the point, $\text{D}\text{?}{}_{\mathrm{T}}$, at which the second derivative becomes zero. This is given by $\text{D}\text{?}{}_{\mathrm{T}}\text{=}\text{exp}\text{(1 ?}\text{a}\text{2b}\text{)}$ when a and b are oppositelt signed.     

Traceability in low-level radioactivity measurements

Various suggested definitions of the term “traceability” are discussed from the standpoint of proposed adoption and use of the concept by the International Organization of Legal Metrology.     

Research priorities for managing the impacts and dependencies of business upon food,energy, water and the environment

Delivering access to sufficient food, energy and water resources to ensure human wellbeing is a major concern for governments worldwide. However, it is crucial to account for the ‘nexus’ of interactions between these natural resources and the consequent implications for human wellbeing. The private sector has a critical role in driving positive change towards more sustainable nexus management and could reap considerable benefits from collaboration with researchers to devise solutions to some of the foremost sustainability challenges of today. Yet opportunities are missed because the private sector is rarely involved in the formulation of deliverable research priorities. We convened senior research scientists and influential business leaders to collaboratively identify the top forty questions that, if answered, would best help companies understand and manage their food-energy-water-environment nexus dependencies and impacts. Codification of the top order nexus themes highlighted research priorities around development of pragmatic yet credible tools that allow businesses to incorporate nexus interactions into their decision-making; demonstration of the business case for more sustainable nexus management; identification of the most effective levers for behaviour change; and understanding incentives or circumstances that allow individuals and businesses to take a leadership stance. Greater investment in the complex but productive relations between the private sector and research community will create deeper and more meaningful collaboration and cooperation.     

Once there was a river: a benefit–cost analysis of rehabilitation of the Jordan River

The Jordan River is among the world’s most famous and culturally and historically significant waterways. The lower stretch of the river, however, has been a victim of development in a water scarce region, with current flows less than 5 % of historical levels. Furthermore, as it functions as an international border in a region of conflict, access to the river and its potential as a tourist attraction has been limited. Recently, there have been numerous calls for rehabilitation of the river. This study presents a first estimate of the economic benefits of such rehabilitation and compares them to the estimated costs. Identical contingent valuation method surveys were administered in Israel, Jordan, and the Palestinian Authority. Evidence from this study shows that, despite the large opportunity costs of increasing environmental flows, rehabilitation of the lower Jordan would produce positive net economic benefits. This is true even though the study estimated only the benefits to local populations, and not to international tourists or those outside the region. Net benefits are maximized when taking a regional, as opposed to strictly national, approach.     

Differential aggregation of polystyrene and titanium dioxide nanoparticles under various salinity conditions and against multiple proteins types

The interaction of nanoplastics (NPls) and engineered nanoparticles (ENPs) with organic matter and environmental pollutants is particularly important. Therefore, their behavior should be investigated under the different salinity conditions, mimicking rivers and coastal environments, to understand this phenomenon in those areas. In this work, we analyzed the elementary characteristics of polystyrene-PS (unmodified surface and modified with amino or carboxyl groups) and titanium dioxide-TiO2 nanoparticles. The effect of salinity on their colloidal properties was studied too. Also, the interaction with different types of proteins (bovine serum albumin-BSA and tilapia proteins), as well as the formation of the BSA corona and its effect on the colloidal stability of nanoparticles, were evaluated. The morphology and dispersion of sizes were more uniform in unmodified-surface PS-NPs (70.5?±?13.7 nm) than in TiO2-NPs (131.2?±?125.6 nm). Likewise, Rama spectroscopy allowed recognizing peaks associated with the PS phenyl group aromatic ring in unmodified-surface PS-NPs (621, 1002, 1582, and 1602 cm^?1). For TiO2-NPs, the data suggest belonging to the tetragonal form, also known as rutile (445, 610 cm^?1). The elevation of salinity dose-dependently decreased NP colloid stability, with more significant variation in the PS-NPs compared to TiO2-NPs. The organic matter is also involved in this phenomenon, differentially as a function of time compared to its absence (unmodified-surface PS-NPs 30 psu/TOC 5 mgL^?1/24 h: 2876.6?±?378.03 nm; unmodified-surface PS-NPs 30 psu/24 h: 2133?±?49.57 nm). In general, the TiO2-NPs demonstrated greater affinity with all proteins tested (0.066 g/L). It was observed that morphology, size, and surface chemical modification intervene in a relevant way in the interaction of the nanoparticles with bovine serum albumin (unmodified-surface PS-NPs 298 K: 6.08E⁺⁰²; 310 K: 6.63E⁺⁰²; TiO2-NPs 298 K: 8.76E⁺⁰²; 310 K: 1.05E⁺⁰³ L mol^?1) and tilapia tissues proteins (from blood, gills, liver, and brain). Their morphology and size also determined the protein corona formation and the NPs’ agglomeration. These findings can provide references during knowledge transfer between NPls and ENPs.