Sustainable risk management of emerging contaminants in municipal wastewaters

This article is available open access through the publisher’s website at the link below. Copyright @ 2009 The Royal Society.The presence of emerging contaminants in municipal wastewaters, particularly endocrine-disrupting compounds such as oestrogenic substances, has been the focus of much public concern and scientific attention in recent years. Due to the scientific uncertainty still surrounding their effects, the Precautionary Principle could be invoked for the interim management of potential risks. Therefore, precautionary prevention risk-management measures could be employed to reduce human exposure to the compounds of concern. Steroid oestrogens are generally recognized as the most significant oestrogenically active substances in domestic sewage effluent. As a result, the UK Environment Agency has championed a ‘Demonstration Programme’ to investigate the potential for removal of steroid oestrogens and alkylphenol ethoxylates during sewage treatment. Ecological and human health risks are interdependent, and ecological injuries may result in increased human exposures to contaminants or other stressors. In this context of limiting exposure to potential contaminants, examining the relative contribution of various compounds and pathways should be taken into account when identifying effective risk-management measures. In addition, the explicit use of ecological objectives within the scope of the implementation of the EU Water Framework Directive poses new challenges and necessitates the development of ecosystem-based decision tools. This paper addresses some of these issues and proposes a species sensitivity distribution approach to support the decision-making process related to the need and implications of sewage treatment work upgrade as risk-management measures to the presence of oestrogenic compounds in sewage effluent

Geogenic and atmospheric sources for volatile organic compounds in fumarolic emissions from Mt. Etna and Vulcano Island (Sicily, Italy)

In this paper, fluid source(s) and processes controlling the chemical composition of volatile organic compounds (VOCs) in gas discharges from Mt. Etna and Vulcano Island(Sicily, Italy) were investigated. The main composition of the Etnean and Volcano gas emissions is produced by mixing, to various degrees, of magmatic and hydrothermal components. VOCs are dominated by alkanes, alkenes and aromatics, with minor, though significant, concentrations of O-, S- and Cl(F)-substituted compounds. The main mechanism for the production of alkanes is likely related to pyrolysis of organic-matterbearing sediments that interact with the ascending magmatic fluids. Alkanes are then converted to alkene and aromatic compounds via catalytic reactions (dehydrogenation and dehydroaromatization, respectively). Nevertheless, an abiogenic origin for the light hydrocarbons cannot be ruled out. Oxidative processes of hydrocarbons at relatively high temperatures and oxidizing conditions, typical of these volcanic-hydrothermal fluids, may explain the production of alcohols, esters, aldehydes, as well as O- and S-bearing heterocycles. By comparing the concentrations of hydrochlorofluorocarbons (HCFCs) in the fumarolic discharges with respect to those of background air, it is possible to highlight that they have a geogenic origin likely due to halogenation of both methane and alkenes. Finally, chlorofluorocarbon (CFC) abundances appear to be consistent with background air, although the strong air contamination that affects the Mt. Etna fumaroles may mask a possible geogenic contribution for these compounds. On the other hand, no CFCs were detected in the Vulcano gases, which are characterized by low air contribution. Nevertheless, a geogenic source for these compounds cannot be excluded on the basis of the present data

Short-Lived Trace Gases in the Surface Ocean and the Atmosphere

The two-way exchange of trace gases between the ocean and the atmosphere is important for both the chemistry and physics of the atmosphere and the biogeochemistry of the oceans, including the global cycling of elements. Here we review these exchanges and their importance for a range of gases whose lifetimes are generally short compared to the main greenhouse gases and which are, in most cases, more reactive than them. Gases considered include sulphur and related compounds, organohalogens, non-methane hydrocarbons, ozone, ammonia and related compounds, hydrogen and carbon monoxide. Finally, we stress the interactivity of the system, the importance of process understanding for modeling, the need for more extensive field measurements and their better seasonal coverage, the importance of inter-calibration exercises and finally the need to show the importance of air-sea exchanges for global cycling and how the field fits into the broader context of Earth System Science

Speciation analysis of iodine and bromine at picogram-per-gram levels in polar ice

Iodine and bromine species participate in key atmospheric reactions including the formation of cloud con- densation nuclei and ozone depletion. We present a novel method coupling a high-performance liquid chromatogra- phy with ion chromatography and inductively coupled plas- ma mass spectrometry, which allows the determination of iodine (I) and bromine (Br) species (IO3−, I−, Br−, BrO3−) at the picogram-per-gram levels presents in Antarctic ice. Chromatographic separation was achieved using an ION- PAC® AS16 Analytical Column with NaOH as eluent. Detection limits for I and Br species were 5 to 9 pg g−1 with an uncertainty of less than 2.5% for all considered species. Inorganic iodine and bromine species have been determined in Antarctic ice core samples, with concentrations close to the detection limits for iodine species, and approximately 150 pg g−1 for Br−. Although iodate (IO3−) is the most abundant iodine species in the atmosphere, only the much rarer iodide (I−) species was present in Antarctic Holocene ice. Bromine was found to be present in Antarctic ice as Br−

A multimodal cell census and atlas of the mammalian primary motor cortex

ABSTRACT We report the generation of a multimodal cell census and atlas of the mammalian primary motor cortex (MOp or M1) as the initial product of the BRAIN Initiative Cell Census Network (BICCN). This was achieved by coordinated large-scale analyses of single-cell transcriptomes, chromatin accessibility, DNA methylomes, spatially resolved single-cell transcriptomes, morphological and electrophysiological properties, and cellular resolution input-output mapping, integrated through cross-modal computational analysis. Together, our results advance the collective knowledge and understanding of brain cell type organization: First, our study reveals a unified molecular genetic landscape of cortical cell types that congruently integrates their transcriptome, open chromatin and DNA methylation maps. Second, cross-species analysis achieves a unified taxonomy of transcriptomic types and their hierarchical organization that are conserved from mouse to marmoset and human. Third, cross-modal analysis provides compelling evidence for the epigenomic, transcriptomic, and gene regulatory basis of neuronal phenotypes such as their physiological and anatomical properties, demonstrating the biological validity and genomic underpinning of neuron types and subtypes. Fourth, in situ single-cell transcriptomics provides a spatially-resolved cell type atlas of the motor cortex. Fifth, integrated transcriptomic, epigenomic and anatomical analyses reveal the correspondence between neural circuits and transcriptomic cell types. We further present an extensive genetic toolset for targeting and fate mapping glutamatergic projection neuron types toward linking their developmental trajectory to their circuit function. Together, our results establish a unified and mechanistic framework of neuronal cell type organization that integrates multi-layered molecular genetic and spatial information with multi-faceted phenotypic properties

Emission of climate relevant volatile organochlorines by plants occurring in temperate forests.

Chlorine, one of the most abundant elements in nature, undergoes a complex biogeochemical cycle in the environment, involved in the formation of volatile organochlorines (VOCls), which in turn can contribute to environmental problems, contaminate natural ecosystems, and are of public health concern. Several industrial and natural sources of VOCls have already been identified; however, data – particularly on the natural sources – are still scarce. The aim of this study was to investigate the diversity of emission of VOCls from soil and several undergrowth plants collected in temperate spruce forest ecosystem and the effect of salting on the VOCl emission of plants. Undergrowth plants were found to emit chloroform (CHCl3) in the range of 2.2–201 pmol/day/g dry weight (DW), tetra-chloromethane (CCl4) 0–23.5 pmol/day/g DW, and tetrachloroethene (C2Cl4) 0–13.5 pmol/day/g DW; the average emission rates were about 10 times higher than that of soil (2.9–47.2; 0–5.8; 0–3.6 pmol/day/g DW of CHCl3; CCl4; C2Cl4 emission, respectively). Addition of sodium chloride solution in most cases caused an increase in the emission of CHCl3 and caused a species specific – effect on the emissions of CCl4 and C2Cl4. The results suggest that the emission of VOCls from spruce forest contribute to the atmospheric input of reactive chlorine; however, on a global scale it is only a minor net source

Physiological measures of climate dependent organismal performance investigated in populations of the lugworm Arenicola marina in a latitudinal cline

The lugworm Arenicola marina is a key organism from the intertidal zone, which is very abundant and shapes the ecosystem by bioturbation. The lugworm is distributed over a wide latitudinal range and exposed to widely fluctuating temperature conditions during seasonal as well as diurnal (tidal) cycles. Animals are specialized to adjust to ambient climate conditions as well as climate variability as evidenced from patterns of latitudinal adaptation and seasonal acclimatisation of thermal tolerance windows. While thermal responses can be found at various levels of organisation we expect climate sensitivity to be highest at the organismal level, the animals balance of oxygen demand and supply. Quantification of the resulting organismal performance range is relevant in the light of global warming and climate change, as exposure to temperatures beyond the performance window likely leads to fitness losses with the consequence of decreased local abundances and eventually a shift in geographical distribution. Performance optima, the width of thermal tolerance windows and their location on the temperature scale were quantified by investigating basic metabolism, growth and muscular exercise on the demand side and ventilation, haemoglobin concentration and oxygen affinity on the supply side in populations of Arenicola marina from the French Atlantic coast, the German North Sea and the Russian White Sea. Performance optima shift to higher temperatures at decreasing latitudes. Seasonal shifts to higher temperatures occur during summer acclimatisation emphasizing a close relationship between the local climate regime and the degree of thermal specialisation of the respective population