Accelerator mass spectrometry measurements of U in groundwater, soil and vegetation at a legacy radioactive waste site.

Low-level radioactive wastes were disposed at the Little Forest Legacy Site (LFLS) near Sydney, Australia between 1960 and 1968. According to the disposal records, U contributes a significant portion of the inventory of actinide activity buried in the LFLS trenches. Although the presence of U in environmental samples from LFLS has been previously inferred from alpha-spectrometry measurements, it has been difficult to quantify because the U and U α-peaks are superimposed.

Molecular Monitoring of EHV-1 in Silently Infected Performance Horses through Nasal and Environmental Sample Testing.

While the main goal in the management of an EHM outbreak focuses on identifying early clinical disease in order to physically separate infected horses, little effort is placed towards monitoring healthy horses. The assumption that EHV-1 shedding parallels clinical disease is erroneous, as subclinical shedders have been shown to be actively involved in viral spread. In an attempt to document the frequency of EHV-1 shedders and their impact on environmental contamination, we collected nasal swabs from 231 healthy horses and 203 environmental samples for the testing of EHV-1 by qPCR.

Rare earth elements and yttrium as tracers of waste/rock-groundwater interactions.

Increasing concentrations of Rare Earth Elements (REE) plus yttrium (REY) are entering the environment due to human activities. The similar chemical behaviour across the whole REY, i.e.

Isotopic evidence for nitrate sources and controls on denitrification in groundwater beneath an irrigated agricultural district.

The application of N fertilisers to enhance crop yield is common throughout the world. Many crops have historically been, or are still, fertilised with N in excess of the crop requirements. A portion of the excess N is transported into underlying aquifers in the form of NO, which is potentially discharged to surface waters.

Evaluation of 1-dimensional nanomaterials release during electrospinning and thermogravimetric analysis.

The growing research interests with engineered nanomaterials in academic laboratories and manufacturing facilities pose potential safety risks to students and workers. New nanoparticle substances, compositions, and processing approaches are developed regularly, creating new health risks which may not have been addressed previously. Accordingly, the Institute of Occupational Medicine conducted field studies at Texas A&M University (TAMU) to characterize possible particle emissions during processing and fabrication of carbon nanotubes, copper nanowires, and polymeric fibers.

Hydrochemical apportioning of irrigation groundwater sources in an alluvial aquifer.

River floodplains sustain irrigated agriculture worldwide. Despite generalised groundwater level falls, limited hard data are available to apportion groundwater sources in many irrigated regions. In this paper, we propose a workflow based on: hydrochemical analysis, water stable isotopes, radiocarbon contents and multivariate statistical analysis to facilitate the quantification of groundwater source attribution at regional scales.

Constraining source attribution of methane in an alluvial aquifer with multiple recharge pathways.

Identifying the source of methane (CH) in groundwater is often complicated due to various production, degradation and migration pathways, particularly in settings where there are multiple groundwater recharge pathways. This study demonstrates the ability to constrain the origin of CH within an alluvial aquifer that could be sourced from in situ microbiological production or underlying formations at depth. To characterise the hydrochemical and microbiological processes active within the alluvium, previously reported hydrochemical data (major ion chemistry and isotopic tracers (H, C, Cl)) were interpreted in the context of CH and carbon dioxide (CO) isotopic chemistry, and the microbial community composition in the groundwater.

Radionuclide distributions and migration pathways at a legacy trench disposal site.

This paper examines the distributions of several anthropogenic radionuclides (Pu, Am, Cs, Sr, Co and H) at a legacy trench disposal site in eastern Australia. We compare the results to previously published data for Pu and tritium at the site. Plutonium has previously been shown to reach the surface by a bath-tubbing mechanism, following filling of the former trenches with water during intense rainfall events.

Global analysis reveals climatic controls on the oxygen isotope composition of cave drip water.

The oxygen isotope composition of speleothems is a widely used proxy for past climate change. Robust use of this proxy depends on understanding the relationship between precipitation and cave drip water δO. Here, we present the first global analysis, based on data from 163 drip sites, from 39 caves on five continents, showing that drip water δO is most similar to the amount-weighted precipitation δO where mean annual temperature (MAT) is < 10 °C.

Cave drip water solutes in south-eastern Australia: Constraining sources, sinks and processes.

Constraining sources and site-specific processes of trace elements in speleothem geochemical records is key to an informed interpretation. This paper examines a 10-year data set of drip water solutes from Harrie Wood Cave, south-eastern Australia, and identifies the processes that control their response to El Niño-Southern Oscillation events which varies the site water balance. The contributions of aerosol and bedrock end-members are quantified via hydrochemical mass balance modelling.

Author Correction: Seasonal total methane depletion in limestone caves.

A correction to this article has been published and is linked from the HTML and PDF versions of this paper. The error has been fixed in the paper.

Chemical characterisation and source identification of atmospheric aerosols in the Snowy Mountains, south-eastern Australia.

Characterisation of atmospheric aerosols is of major importance for: climate, the hydrological cycle, human health and policymaking, biogeochemical and palaeo-climatological studies. In this study, the chemical composition and source apportionment of PM (particulate matter with aerodynamic diameters less than 2.5μm) at Yarrangobilly, in the Snowy Mountains, SE Australia are examined and quantified.

Physiologically-based pharmacokinetic and toxicokinetic models for estimating human exposure to five toxic elements through oral ingestion.

Biological monitoring and physiologically-based pharmacokinetic (PBPK) modelling are useful complementary tools in quantifying human exposure to elements in the environment. In this work, we used PBPK models to determine the optimal time for collecting biological samples in a longitudinal study to determine if participants who consumed allotment produce had been exposed to arsenic, cadmium, chromium, nickel or lead. There are a number of PBPK models for these elements published in the literature, which vary in size, complexity and application, given the differences in physiochemical properties of the elements, organs involved in metabolism and exposure pathways affected.

Seasonal total methane depletion in limestone caves.

Methane concentration in caves is commonly much lower than the external atmosphere, yet the cave CH depletion causal mechanism is contested and dynamic links to external diurnal and seasonal temperature cycles unknown. Here, we report a continuous 3-year record of cave methane and other trace gases in Jenolan Caves, Australia which shows a seasonal cycle of extreme CH depletion, from ambient ~1,775 ppb to near zero during summer and to ~800 ppb in winter. Methanotrophic bacteria, some newly-discovered, rapidly consume methane on cave surfaces and in external karst soils with lifetimes in the cave of a few hours.

Review on the Processing and Properties of Polymer Nanocomposites and Nanocoatings and Their Applications in the Packaging, Automotive and Solar Energy Fields.

For the last decades, nanocomposites materials have been widely studied in the scientific literature as they provide substantial properties enhancements, even at low nanoparticles content. Their performance depends on a number of parameters but the nanoparticles dispersion and distribution state remains the key challenge in order to obtain the full nanocomposites' potential in terms of, e.g.

A comparison of control banding tools for nanomaterials.

Control banding (CB) is a useful approach to evaluate and control the risk of exposure to nanomaterials (NM) due to uncertainty surrounding their toxicity and challenges associated with their measurement. Four CB tools specifically developed for NMs (NanoSafer, Stoffenmanager-Nano, NanoTool, and the Precautionary matrix) have been evaluated for their changes to differences in hazard and exposure input data. The hazard and exposure classification were also compared with experimental data.

Assessing Connectivity Between an Overlying Aquifer and a Coal Seam Gas Resource Using Methane Isotopes, Dissolved Organic Carbon and Tritium.

Coal seam gas (CSG) production can have an impact on groundwater quality and quantity in adjacent or overlying aquifers. To assess this impact we need to determine the background groundwater chemistry and to map geological pathways of hydraulic connectivity between aquifers. In south-east Queensland (Qld), Australia, a globally important CSG exploration and production province, we mapped hydraulic connectivity between the Walloon Coal Measures (WCM, the target formation for gas production) and the overlying Condamine River Alluvial Aquifer (CRAA), using groundwater methane (CH4) concentration and isotopic composition (δ(13)C-CH4), groundwater tritium ((3)H) and dissolved organic carbon (DOC) concentration.

Foresight Study on the Risk Governance of New Technologies: The Case of Nanotechnology.

Technology-led innovation represents an important driver of European economic and industrial competitiveness and offers solutions to societal challenges. In order to facilitate responsible innovation and public acceptance, a need exists to identify and implement oversight approaches focused on the effective risk governance of emerging technologies. This article describes a foresight study on the governance of new technologies, using nanotechnology as a case example.

How important is drinking water exposure for the risks of engineered nanoparticles to consumers?

This study explored the potential for engineered nanoparticles (ENPs) to contaminate the UK drinking water supplies and established the significance of the drinking water exposure route compared to other routes of human exposure. A review of the occurrence and quantities of ENPs in different product types on the UK market as well as release scenarios, their possible fate and behaviour in raw water and during drinking water treatment was performed. Based on the available data, all the ENPs which are likely to reach water sources were identified and categorized.

ITS-NANO--prioritising nanosafety research to develop a stakeholder driven intelligent testing strategy.

Background: To assess the risk of all nanomaterials (NMs) on a case-by-case basis is challenging in terms of financial, ethical and time resources. Instead a more intelligent approach to knowledge gain and risk assessment is required.

Methods: A framework of future research priorities was developed from the accorded opinion of experts covering all major stake holder groups (government, industry, academia, funders and NGOs).

Trench 'bathtubbing' and surface plutonium contamination at a legacy radioactive waste site.

Radioactive waste containing a few grams of plutonium (Pu) was disposed between 1960 and 1968 in trenches at the Little Forest Burial Ground (LFBG), near Sydney, Australia. A water sampling point installed in a former trench has enabled the radionuclide content of trench water and the response of the water level to rainfall to be studied. The trench water contains readily measurable Pu activity (~12 Bq/L of (239+240)Pu in 0.

[Enteric alpha defensin 5 is secreted into the blood stream by colon tumors].

It was demonstrated that enteric alpha-defensin 5 is undetectable in five blood serum samples of healthy donors, whereas its processed form is present in two out of five serum samples of colon cancer patients. Obtained results open a possibility of serological diagnosis of colon tumors in high risk cancer patients.

Nanoscale reference materials for environmental, health and safety measurements: needs, gaps and opportunities.

The authors critically reviewed published lists of nano-objects and their physico-chemical properties deemed important for risk assessment and discussed metrological challenges associated with the development of nanoscale reference materials (RMs). Five lists were identified that contained 25 (classes of) nano-objects; only four (gold, silicon dioxide, silver, titanium dioxide) appeared on all lists. Twenty-three properties were identified for characterisation; only (specific) surface area appeared on all lists.

Nano-TiO₂--feasibility and challenges for human health risk assessment based on open literature.

This study aims at investigating feasibility and challenges associated with conducting a human health risk assessment for nano-titanium-dioxide (nano-TiO₂) based on the open literature by following an approach similar to a classical regulatory risk assessment. Gaps in the available data set, both in relation to exposures and hazard, do not allow reaching any definite conclusions that could be used for regulatory decision-making. Results show that repeated inhalation in the workplace and possibly consumer inhalation may cause risks.