Interacting effects of cation saturation and drying, freezing, or aging on the extractability of nonylphenol and phenanthrene from a sandy soil

Purpose

The structure and properties of the soil organic matter and its interactions with solutes may be altered by changes in soil chemistry and by the aging of soil. The main objective of this study was to investigate the effect of long-term aging and cation saturation of soil on the extractability and degradability of two hydrophobic xenobiotics in soil. In addition, it was tested if drying or freezing of soils can accelerate the relevant aging processes.

Materials and methods

The sandy topsoil was treated by either 0.1?M NaCl, CaCl₂, AlCl₃ solutions or water and samples were sterilized by ??-radiation and spiked with ¹⁴C-labeled nonylphenol (NP) or phenanthrene (Phe) at 10???g?g^?1 of soil. Samples were then used in four parallel experimental setups: (1) 9?months of aging under sterile conditions, (2) inoculation by native original soil with further 7?months of aging (bioaging), (3) drying and wetting or (4) freezing and thawing of soils. After different time intervals, the extractability of xenobiotics with water, cyclodextrin, and ethanol was investigated.

Results and discussion

During 9?months of aging under sterile conditions a continuous decrease of NP and Phe extractability and an increase of the non-extractable fraction occurred. During the 7?months of biologically active aging, the mineralization of NP was lower than of Phe while more NP remained extractable than Phe. In comparison to the sterile aging, the bioaging led to a less formation of non-extractable residues of NP and Phe. The long-term sterile aging effects on NP-extractability were also achieved by short-term freezing and thawing of the soils, while aging of Phe was better mimicked by drying?Cwetting cycles. The effects of cation saturation of soils on xenobiotics extractability were less pronounced.

Conclusions

Sterile aging, bioaging, freezing, and thawing facilitate the formation of the non-extractable fraction of NP and Phe in the soils. Different cation treatments alter soil properties, but the effects on aging of NP and Phe in soils were negligible.     

Monitoring shallow methane‐derived authigenic carbonate: Insights from a UK Marine Protected Area

1. Methane‐derived authigenic carbonate (MDAC) is a biogenic rocky substrate formed by microbial assemblages below the seabed. It performs important ecosystem functions, including the provision of reef‐like habitats on soft sediments and the sequestration of carbon.
2. The protection of MDAC is limited at the global scale; however, 27 marine protected areas (MPAs) have been designated in European waters for ‘cold seep’ MDAC, mainly in shallow waters (<200 m). Few studies have been conducted on these habitats from a conservation perspective.
3. The effective management of MDAC structures requires an understanding of their ecology and physical characteristics in a healthy condition. This is best achieved using a multidisciplinary approach to provide evidence on predefined aspects of MDAC structures, termed feature attributes, which can be assessed to determine habitat condition over time.
4. This article presents the first UK effort to develop a multidisciplinary approach to monitoring shallow MDAC feature attributes, using the Croker Carbonate Slabs Special Area of Conservation (SAC) as a case study. A range of remote and physical survey methods were used to characterize the MDAC and associated relatively unimpacted and healthy biological communities.
5. The data confirm that the SAC contains the largest known area of shallow MDAC in European waters, that methane release is ongoing, and that MDAC is still likely to be forming. Specialized chemoautotrophic fauna were not recorded, possibly due to the dominance of fauna that derive carbon (ultimately) from photosynthesis. Five epifaunal taxa were found to be associated with MDAC, but not with the surrounding sediments.
6. The broad multidisciplinary survey allowed a detailed characterization of shallow MDAC but was resource intensive. We recommend a low‐resource monitoring strategy to deliver cost‐effective and robust evidence for condition assessment and suggest further studies to contextualize future interpretations of change.

     

A Collaborative Evaluation of LC-MS/MS Based Methods for BMAA Analysis: Soluble Bound BMAA Found to Be an Important Fraction

Exposure to β-N-methylamino-l-alanine (BMAA) might be linked to the incidence of amyotrophic lateral sclerosis, Alzheimer’s disease and Parkinson’s disease. Analytical chemistry plays a crucial role in determining human BMAA exposure and the associated health risk, but the performance of various analytical methods currently employed is rarely compared. A CYANOCOST initiated workshop was organized aimed at training scientists in BMAA analysis, creating mutual understanding and paving the way towards interlaboratory comparison exercises. During this workshop, we tested different methods (extraction followed by derivatization and liquid chromatography coupled to tandem mass spectrometry (LC-MS/MS) analysis, or directly followed by LC-MS/MS analysis) for trueness and intermediate precision. We adapted three workup methods for the underivatized analysis of animal, brain and cyanobacterial samples. Based on recovery of the internal standard D₃BMAA, the underivatized methods were accurate (mean recovery 80%) and precise (mean relative standard deviation 10%), except for the cyanobacterium Leptolyngbya. However, total BMAA concentrations in the positive controls (cycad seeds) showed higher variation (relative standard deviation 21%–32%), implying that D₃BMAA was not a good indicator for the release of BMAA from bound forms. Significant losses occurred during workup for the derivatized method, resulting in low recovery (<10%). Most BMAA was found in a trichloroacetic acid soluble, bound form and we recommend including this fraction during analysis.     

Floristic diversity of valonia oak silvopastoral woodlands in Greece

Valonia oak (Quercus ithaburensis subsp. macrolepis (Kotschy) Hedge and Yaltirik), a deciduous species grown in the xerothermic conditions of the east Mediterranean zone of Europe, forms woodlands of open canopy that permits adequate light to reach the ground thus sustaining an exceptionally rich flora. In Greece, these woodlands are mainly used for livestock grazing and considered important silvopastoral systems. Nowadays, most of them are abandoned and degraded as a result of inappropriate management. For the effective evaluation and sustainable management of these woodlands and the establishment of reliable monitoring systems, a detailed analysis of their plant diversity characteristics across Greece is needed. This paper aims at determining and comparing floristic diversity measures as well as at assessing the impact of human activities on vegetation and floristic diversity of the most characteristic valonia oak silvopastoral woodlands of Greece. It was found that the truncated log-normal model adequately predicts the species abundance data for eleven out of the twelve woodlands. From the statistical comparison of the diversity indices Q-statistic, Berger–Parker dominance index and Shannon-Wiener measure of equitability, three groups of these woodlands can be distinguished (a) the high-richness group of Pentalofos, Lesvos, Lakonia and Thesprotia, (b) the medium-richness group of Kriti Island, Alexandroupoli, Strofylia and Galaxidi, and (c) the low-richness group of Kea Island, Amfilohia, Almyros and Lilaia. However, the Rényi’s diversity ordering diagram showed that, generally, in low levels of entropy inconsistency is the rule and no clear pattern of diversity is extracted reflecting the impact of complex factors. Among them, those related to management seem to mostly determine plant diversity of valonia oak silvopastoral woodlands, with abiotic factors having an occasionally supporting role. Changes of species richness and evenness due to livestock grazing as well as acorn and wood harvesting are further discussed.     

Gastrointestinal Parasites of Stabled and Grazing Horses in Central and Northern Greece

The aim of this investigation was to compare parasites found in feces from stabled and grazing horses in Greece. For this, a total of 223 fecal samples were collected from horses from various parts of Central and Northern Greece. One hundred fifty were stabled and 73 were grazing horses, used for riding, working, or breeding. One hundred came from seven riding clubs, 73 from one breeding farm, and 50 were work horses from five farms. Parasitologic investigation was performed by applying three fecal examination techniques (Teleman's, zinc flotation, and stained smears) to detect ova, larvae, and oocysts of parasites. It was found that 77 the 223 horses (34.5%) in the study were infected with one or more parasite species. In the stabled horses, the most common parasites detected were eggs of strongyles, Strongyloides spp, Anoplocephala spp, Habronema spp, and Parascaris equorum and oocysts of Eimeria spp and Cryptosporidium spp; in the grazing horses, Anoplocephala spp. Strongyles were significantly more prevalent in the group of stabled horses than in the other group (P < .05). The results of the current study demonstrate that parasite infection is highly prevalent in horses in Greece.     

Attract-and-kill strategy. Laboratory studies on hatched larvae of Culex pipiens

The attract‐and‐kill strategy is a new pest management technique that presupposes the intelligent combination of an attracting agent (e.g. pheromone) and a killing agent (e.g. insecticide). In the present study, the potential combination of the microencapsulated synthetic oviposition pheromone 6‐acetoxy‐5‐hexadecanolide with an insecticide has been tested. Initially, polyurea microcapsules containing 6‐acetoxy‐5‐hexadecanolide, the synthetic mixture of diastereomers of the oviposition pheromone of the mosquito species Culex quinquefasciatus Say (Diptera: Culicidae), were studied. Laboratory bioassays were performed to confirm the bioactivity of the microencapsulated pheromone on the oviposition activity of Culex pipiens L. biotype molestus Førskal (Diptera: Culicidae) with the aim of determining the optimum dose for oviposition response. Its effect was dose dependent, revealing an optimum dose of 300 mg of dried microcapsules. Attractancy over time was also studied. The microencapsulated pheromone was found to be sufficiently attractive to gravid female mosquitoes for a period of 40 days. Finally, the combination of the synthetic pheromone with the control agent temephos showed both an acceptable oviposition activity and sufficient larvicidal effect. Copyright © 2007 Society of Chemical Industry