Hot Articles – Page 15 – Environmental Science: Processes & Impacts blog

Archive for the ‘Hot Articles’ Category

HOT: asking the right questions to understand global climate change

20 May 2011

Understanding the impact of long term human exposure to organic contaminants in the Arctic as a result of global climate change is no mean feat – we barely understand the complicated Northern ecosystem as it is. This comprehensive review from James Armitage and colleagues at the University of Toronto carefully outlines our existing knowledge of the system – and the gaps in it.

Their goal is to identify the key research questions that must be answered in order to increase our ability to see what the future holds for a warmer Arctic – why not check out the article today, you might get some ideas for your next project!

This article is free to access for the next four weeks:

Global climate change and contaminants—an overview of opportunities and priorities for modelling the potential implications for long-term human exposure to organic compounds in the Arctic
James M. Armitage, Cristina L. Quinn and Frank Wania
J. Environ. Monit., 2011, Advance Article
DOI: 10.1039/C1EM10131E

Why not also take a look at this review article by Susan Nash at Griffith University, describing the challenges faced by the research community in obtaining accurate information on the impact of persistent organic pollutants in Antarctica:

Persistent organic pollutants in Antarctica: current and future research priorities
Susan Bengtson Nash
J. Environ. Monit., 2011, 13, 497-504

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HOT: addressing key issues for sustainable agriculture

13 May 2011

In this Perspective article David Lindenmayer (The Australian National University) and Gene Likens (Cary Institute of Ecosystem Studies) prevent their view on developing effective monitoring programs for agriculture.

The article was written in response to an opinion piece published in Nature proposing a global network for agricultural monitoring, which the authors believe fails to successfully address this important issue. They argue that the framework proposed by Sachs et al is likely to be ineffective, due to their analysis of previous monitoring programs. They present a new framework, based on their research which aims to understand change in environmental phenomena in agricultural ecosystems and answer critical questions about sustainable agriculture.

This interesting piece is currently free to access for 4 weeks – why not read it and give us your opinion?

Effective monitoring of agriculture
David B. Lindenmayer and Gene E. Likens
J. Environ. Monit., 2011, Advance Article
DOI: 10.1039/C0EM00691B

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HOT: sorption of nano-fullerene clusters in soil – hydrophillic or hydrophobic?

06 May 2011

C₆₀ molecules are well as hydrophobic compounds with a high K_OC value. But what happens when fullerene molecules are released into the environment?

Mohsen Forouzangohar and Rai Kookana from the Commonwealth Scientific and Industrial Research Organisation have expanded on previous work that considered environmental C₆₀sorption on a purely molecular basis and assumed phase partitioning into soil organic matter is the main mechanism for the sorption of the hydrophobic C₆₀ molecules. They have shown that they may actually exist in the form of nano-C₆₀ clusters in the environment – rather than as C₆₀ molecules – and that hydrophobic interactions of this compound with soil organic matter are not likely to be the dominant mechanism governing its mobility in the environment. Instead, net surface charge and hydrophilic interactions are expected to play a much more significant role, which could lead to much higher aqueous concentrations of the fullerenes in the environment than previously anticipated.

This interesting article is the cover article from our themed issue on Environmental Nanotechnology and it’s free to access for 6 weeks:

Sorption of nano-C60 clusters in soil: hydrophilic or hydrophobic interactions?
Mohsen Forouzangohar and Rai S. Kookana
J. Environ. Monit., 2011, 13, 1190-1194
DOI: 10.1039/C0EM00689K

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HOT article: assessing aquatic titanium dioxide nanomaterial exposure

28 Apr 2011

As the use of nanoparticles in consumer and commercial products continues to rise, information on their effect on the environment is crucial. Numerous studies have been conducted on nanoparticle toxicity but exposure studies have received, well, less exposure.

This paper offers a method for collecting and analysing titanium dioxide nanomaterials from municipal wastewater treatment plants – a major entry point of nanoparticles into aquatic environments. Paul Westerhoff (Arizona State University) and colleagues show that there is a clear possibility of TiO₂ nanoparticles being released into the environment when conventional separation and filtration methods are used. Microfiltration appears to reduce the levels of nanoparticles in the discharged effluent however.

Interestingly, the study also found that silica nanoparticles were present in much higher concentrations than TiO₂, quantification of which were beyond the scope of this study, but are the subject of ongoing research.

This HOT article is part of our forthcoming themed issue on Environmental Nanotechnology and is free to access for 4 weeks.

Occurrence and removal of titanium at full scale wastewater treatment plants: implications for TiO2 nanomaterials
Paul Westerhoff, Guixue Song, Kiril Hristovski and Mehlika A. Kiser
J. Environ. Monit., 2011, Advance Article
DOI: 10.1039/C1EM10017C

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HOT article: studying silver and cerium dioxide nanoparticle toxicity in Daphnia magna

22 Apr 2011

This HOT article from Birgit Gaiser (Edinburgh Napier University) and colleagues presents a detailed study into the effect of silver and cerium dioxide nanoparticles on the common freshwater test organism Daphnia magna.

Both species of nanoparticles (NPs) are currently used extensively – silver in consumer products for their antibacterial properties, and cerium dioxide in slurries for silicon wafer planarization – and usage is only expected to increase. It is therefore essential to to assess their potentially damaging effects on the environment due to factors such as particle size, material, and concentration. This study investigated acute and chronic toxicity of well characterised nano- and micron- sized particles in Daphnia magna, confirming the “nano-hypothesis” – that nano-sized particles were more toxic than equal concentrations of micron-sized particles (for Ag NPs). Confirming previous studies, CeO₂ NPs were only toxic at concentrations significantly above environmentally relevant levels. The study also uncovered sub-lethal effects of silver nanoparticles, such as moulting and impaired growth of D. magna, which the authors hope will improve our understanding of the mechanism that causes toxic effects.

This HOT article is part of our forthcoming themed issue on Environmental Nanotechnology and is free to access for 4 weeks. The careful characterisation of the nanoparticles makes this study particularly valuable – why not read Robert MacCuspie’s article on the challenges for physical characterization of silver nanoparticles which is also part of this themed issue.

Effects of silver and cerium dioxide micro- and nano-sized particles on Daphnia magna
Birgit K. Gaiser, Anamika Biswas, Philipp Rosenkranz, Mark A. Jepson, Jamie R. Lead, Vicki Stone, Charles R. Tyler and Teresa F. Fernandes
J. Environ. Monit., 2011, Advance Article
DOI: 10.1039/C1EM10060B, Paper

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HOT article: the silver standard – challenges in characterising the environmental impact of silver nanomaterials

14 Apr 2011

This HOT article reports a collaborative effort between the US Environmental Protection Agency and National Institute of Standards and Technology to facilitate intercomparison of sometimes conflicting environmental risk experiment results for silver nanoparticles.

Silver nanoparticles have become the most widely used of all nanoparticles reported in consumer products due to their well known antibacterial and antifungal properties, but with increased use comes increased concern – do they pose a health and safety or environmental risk? There is a huge amount of literature data available on silver nanoparticles, but as there is no standard procedure for their manufacture, stabilization, or initial characterization it can be difficult for regulatory authorities to make comparisons between different datasets and thus draw meaningful conclusions.

Here, Robert MacCuspie and Kim Rogers et al. have analysed a range of silver nanoparticle materials with different analytical methods and initial dispersion conditions to demonstrate how measurement methods, agglomeration state and dispersion conditions influence the reported size distributions of said materials. They also present an approach to developing routine screening for the nanomaterials.

This HOT article is part of our forthcoming themed issue on Environmental Nanotechnology and is free to access for 4 weeks.

Challenges for physical characterization of silver nanoparticles under pristine and environmentally relevant conditions
Robert I. MacCuspie, Kim Rogers, Manomita Patra, Zhiyong Suo, Andrew J. Allen, Matthew N. Martin and Vincent A. Hackley
J. Environ. Monit., 2011, Advance Article
DOI: 10.1039/C1EM10024F, Paper

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HOT article: hot spot or not? Polybrominated diphenyl ether contamination in Laizhou Bay examined

07 Apr 2011

As part of our themed issue focussing on environmental science in Asia and the Pacific, this HOT article from Jianhui Tang , Gan Zhang and co-workers from Chinese Academy of Sciences laboratories looks at the impact of
polybrominated diphenyl ethers (PBDEs). PBDEs are a class of brominated fire retardants (BFRs) that have attracted significant attention due to environmental and health concerns.

Despite the fact that some PBDEs (namely penta- and octa-BDEs) have been listed under the Stockholm Convention and banned in several countries, in China both production and consumption of some PBDE-containing brominated fire retardants have risen rapidly in recent years. This study focuses on the Laizhou Bay area, which is home to the biggest manufacturing base for BFRs in China. By sampling river and coastal sediment in the area they looked at the source and fate of PBDE contaminants in the area, discovering that BDE 209 is the predominant PBDE congener present. Interestingly, however, overall PBDE concentrations were lower than other literature data from European and US ‘hot spots’.

Read more of this thoughtful and thorough study – which comes highly recommended by the referees – it’s currently free to access for four weeks.

Polybrominated diphenyl ethers (PBDEs) in the riverine and marine sediments of the Laizhou Bay area, North China
Xiaohui Pan, Jianhui Tang, Jun Li, Guangcai Zhong, Yingjun Chen and Gan Zhang
J. Environ. Monit., 2011, 13, 886-893
DOI: 10.1039/C1EM10169B

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HOT article: triclosan distribution down under

24 Mar 2011

The anti-microbial agent triclosan has been used extensively in the last four decades, however concerns regarding its environmental impact on marine systems are relatively recent.

Milena Fernandes (South Australian Water Corporation) and co-workers investigated the distribution of wastewater-borne triclosan and its methylated derivative in surface sediments of a coastal inlet to determine the factors affecting transport and benthic preservation. The location studied is of interest as it is an important nursery habitat and provides sanctuary to a resident population of bottlenose dolphins.

Fernandes demonstrates that the pathways leading to dispersal are different for triclosan and methyl-triclosan discharged with wastewater, with triclosan having a larger area of impact. Triclosan accumulated in deeper sites containing finer sediment fractions, where in situ biological methylation was enhanced. Methyl-triclosan was absent from shallower sediments, potentially as a result of photodegradation of the parent compound.

This HOT article is part of our forthcoming SETAC themed issue focussing on Asia/Pacific environmental science and is free to access for 4 weeks.

The distribution of triclosan and methyl-triclosan in marine sediments of Barker Inlet, South Australia
Milena Fernandes, Ali Shareef, Rai Kookana, Sam Gaylard, Sonja Hoare and Tim Kildea
J. Environ. Monit., 2011, Advance Article
DOI: 10.1039/C0EM00612B

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HOT article: investigating lesser-studied flame retardants

10 Mar 2011

This HOT paper from 2010 Emerging Investigator Hans Peter Arp investigates levels of some lesser-studied brominated fire retardants.

Recent years have seen an increase in pressure to find ‘new’ fire retardants, that are less stringently regulated than their polybrominated biphenyl and polybrominated diphenyl ether cousins. Arp and colleagues looked at three brominated monoaromatics that have been in use for several decades and have been found in environmental samples, but have received far less overall attention.

Their findings indicate, that although there is not yet any cause for concern, the levels of the BFRs in samples (in particular hexabromobenzene) certainly warrant further study. The group are careful to point out that it is difficult at this stage to determine whether the levels reported suggest an increase in production levels, transformation products or interest by researchers, and that more information could be obtained through dated sediment or ice core studies.

This interesting article is currently free to access until April, so download the full paper today:

Presence and partitioning properties of the flame retardants pentabromotoluene, pentabromoethylbenzene and hexabromobenzene near suspected source zones in Norway
Hans Peter H. Arp, Thomas Møskeland, Patrik L. Andersson and Jenny Rattfelt Nyholm
J. Environ. Monit., 2011, Advance Article
DOI: 10.1039/C0EM00258E

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HOT: cheap consumer electronics to help measure noise pollution

09 Mar 2011

Many of us have suffered a sleepless night from wailing sirens or been distracted at work by incessant drilling from a construction site, and we all know that annoying noises have the capacity to drive us round the bend. The European Environmental Noise Directive requires member states to draw up ‘strategic noise maps‘ so that noise pollution can be monitored and the problem tackled in the longer term.

However creating these noise maps is not a cheap or easy task – most are estimates from calculations, the input of which are predictions from traffic models and limited geometrical acoustics approaches. As is always the case, the more complex the calculation, the higher the computing time and cost, so a comprise is often made between cost and accuracy. Although the technology exists for more accurate noise measurement networks, their application is very limited due to the high cost of logging units and sensors (microphones) found on the commercial market.

Timothy Van Renterghem (Ghent University) and co-workers have now come up with a solution – the surge in microphones used in laptops, mobile phones, mp3 players etc has driven down their cost, but not at the expense of quality – the technology is very similar to high-quality measurement microphones. Logging the raw microphone signal
has also shifted from dedicated hardware to PC-based systems, with significant cost reductions.

In this paper Van Renterghem and team have shown that the cheap consumer microphones perform well against their more expensive dedicated monitoring cousins, with only small level differences compared to reference equipment.

The study is part of a longer term project on affordable environmental noise monitoring – read the full paper online here, the article is free to access until April.

On the ability of consumer electronics microphones for environmental noise monitoring
Timothy Van Renterghem, Pieter Thomas, Frederico Dominguez, Samuel Dauwe, Abdellah Touhafi, Bart Dhoedt and Dick Botteldooren
J. Environ. Monit., 2011, Advance Article
DOI: 10.1039/C0EM00532K, Paper

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