Assessing social vulnerability to climate change in Samoa

Climate change severely impacts on the natural and socio-economic systems of the Pacific Islands. Samoa, a small insular state of the region, is characterized by widespread awareness of climate change reflected by its leading international role. This also makes Samoa a potentially exemplary reference for the Pacific Islands. Against this backdrop, the overall aim of this article is to investigate the notion of social vulnerability and measure its dimensions in Samoa through a specific index: the Samoa Social Vulnerability Index (SSVI). The SSVI may yield better understanding of the characteristics and dynamics of social vulnerability, as well as information for fostering adaptation strategies in Samoa and in the Pacific Islands. In particular, the article first outlines the major vulnerabilities to climate change in Samoa and then analyses the composite notion of social vulnerability. On this basis, the article methodologically specifies, designs and constructs the SSVI. Afterwards, it uses such index for measuring the dimensions of social vulnerability in Samoa’s districts. Finally, some considerations are made concerning the policy relevance of the SSVI and its potential regional role.     

Dioxins (polychlorinated dibenzo-p-dioxins and polychlorinated dibenzo-furans) in traditional clay products used during pregnancy

Geophagy, the practice of consuming clay or soil, is encountered among pregnant women in Africa, Eastern Asia and Latin America, but also in Western societies. However, certain types of clay are known to contain high concentrations of polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs). The aim of this study was to determine the PCDD/F contents of orally consumed clays purchased from Dutch and African markets. Congener patterns were compared with those of pooled human milk samples collected in eight African countries, to investigate a possible relationship with clay consumption. From the Dutch market thirteen clay products were examined, seven of African and six of Suriname origin. From seven African countries, twenty clay products were collected. All 33 clay products were screened with a cell-based bioassay and those showing a high response were analyzed by GC/HRMS. High PCDD/F concentrations were measured in three clay products from the Dutch market, ranging from 66 to 103 pg TEQ g^-1, whereas clay products from African countries were from 24 to 75 pg TEQ g^-1. Patterns and relatively high concentrations of PCDD/Fs in human milk samples from the Democratic Republic of the Congo and Côte d’Ivoire suggest a relationship with the consumption of contaminated clay. Frequent use of PCDD/F contaminated clay products during pregnancy may result in increased exposure of the mother and subsequently the developing fetus and new-born child. The use of these contaminated clays during pregnancy should be carefully considered or even discouraged.     

Sorption and photodegradation of chlorpyrifos on riparian and aquatic macrophytes

Surface water bodies may become contaminated via spray drift following pesticide application. In this investigation, the photodegradation and sorption of chlorpyrifos was studied in four riparian macrophytes representative of Mediterranean flora (Phragmites australis, Iris pseudacorus, Equisetum pratense and Typha latifolia). The results of experiments with both the active ingredient and the formulation DURSBAN 48® EC confirm the ability of these species to interact with chemicals such as chlorpyrifos. The maximum sorption of chlorpyrifos at equilibrium was observed in Phragmites australis (22%). And, the maximum instantaneous sorption of chlorpyrifos was observed in the dried biomass of Phragmites australis (49%). The epicuticular waxes present on leaves influence photodegradation processes, resulting in a decrease in chlorpyrifos persistence depending on the nature of the extract. The half-life of chlorpyrifos residues in leaf waxes decreased from 34 to 99 minutes when irradiated.     

Leaching of S-metolachlor,terbuthylazine, desethyl-terbuthylazine,mesotrione, flufenacet,isoxaflutole, and diketonitrile in field lysimeters as affected by the time elapsed between spraying and first leaching event

The effect of elapsed time between spraying and first leaching event on the leaching behavior of five herbicides (terbuthylazine, S-metolachlor, mesotrione, flufenacet, and isoxaflutole) and two metabolites (desethyl-terbuthylazine and diketonitrile) was evaluated in a 2011–2012 study in northwest Italy. A battery of 12 lysimeters (8.4 m² long with a depth of 1.8 m) were used in the study, each filled with silty-loam soil and treated during pre-emergence with the selected herbicides by applying a mixture of commercial products Lumax (4 L ha^?1) and Merlin Gold (1 L ha^?1). During treatment periods, no gravity water was present in lysimeters. Irrigation events capable of producing leaching (40 mm) were conducted on independent groups of three lysimeters on 1 day after treatment (1 DAT), 7 DAT, 14 DAT, and 28 DAT. The series was then repeated 14 days later. Leachate samples were collected a few days after irrigation; compounds were extracted by solid phase extraction and analyzed by high-performance liquid chromatography and gas chromatography–mass spectrometry. Under study conditions, terbuthylazine and S-metolachlor showed the highest leaching potentials. Specifically, S-metolachlor concentrations were always found above 0.25 µg L^?1. Desethyl-terbuthylazine was often detected in leached waters, in most cases at concentrations above 0.1 µg L^?1. Flufenacet leached only when irrigation occurred close to the time of herbicide spraying. Isoxaflutole and mesotrione were not measured (<0.1 µg L^?1), while diketonitrile was detected in concentrations above 0.1 µg L^?1 on 1 DAT in 2011 only.     

Evaluation of the MIDTAL microarray chip for monitoring toxic microalgae in the Orkney Islands, U.K.

Harmful or nuisance algal blooms can cause economic damage to fisheries and tourism. Additionally, toxins produced by harmful algae and ingested via contaminated shellfish can be potentially fatal to humans. The seas around the Orkney Islands, UK currently hold a number of toxic algal species which cause shellfishery closures in most years. Extensive and costly monitoring programs are carried out to detect harmful microalgae before they reach action levels. However, the ability to distinguish between toxic and non-toxic strains of some algae is not possible using these methods. The microarrays for the detection of toxic algae (MIDTAL) microarray contains rRNA probes for toxic algal species/strains which have been adapted and optimized for microarray use. In order to investigate the use of the chip for monitoring in the Orkney Islands, samples were collected between 2009 and 2011 from Brings Deep, Scapa Flow, Orkney Islands, UK; RNA was extracted and hybridized with generation 2 and 3.1 of the chip. The data were then compared to cell counts performed under light microscopy and in the case of Alexandrium tamarense to qPCR data targeting the saxitoxin gene and the LSU-rRNA gene. A good agreement between cell numbers and microarray signal was found for A. tamarense, Pseudo-nitzschia sp., Dinophysis sp. (r?<?0.5, for all) in addition to this there the chip successfully detected a large bloom of Karenia mikimotoi (r?<?0.70) in August and September 2011. Overall, there was good improvement in probe signal between generation 2 and generation 3.1 of the chip with much less variability and more consistent results and better correlation between the probes. The chip performed well for A. tamarense group I signal to cell numbers in calibrations (r?>?0.9). However, in field samples, this correlation was slightly lower suggesting interactions between all species in the sample may affect signal. Overall, the chip showed it could identify the presence of target species in field samples although some work is needed to improve the quantitative nature of the chip before it would be suitable for monitoring in the Orkney Islands.     

Sorption and desorption of sulfentrazone in Brazilian soils

This study was undertaken to obtain information about the behavior of sulfentrazone in soil by evaluating the sorption and desorption of the herbicide in different Brazilian soils. Batch equilibrium method was used and the samples were analyzed by high performance liquid chromatography. Based on the results obtained from the values of Freundlich constants (Kf), we determined the order of sorption (Haplic Planosol < Red-Yellow Latosol < Red Argisol < Humic Cambisol < Regolitic Neosol) and desorption (Regolitic Neosol < Red Argisol < Humic Cambisol < Haplic Planosol < Red-Yellow Latosol) of sulfentrazone in the soils. The process of pesticide sorption in soils was dependent on the levels of organic matter and clay, while desorption was influenced by the organic matter content and soil pH. Thus, the use of sulfentrazone in soils with low clay content and organic matter (low sorption) increases the probability of contaminating future crops.     

Clay-sewage sludge co-pyrolysis. A TG-MS and Py-GC study on potential advantages afforded by the presence of clay in the pyrolysis of wastewater sewage sludge

Wastewater sewage sludge was co-pyrolyzed with a well characterized clay sample, in order to evaluate possible advantages in the thermal disposal process of solid waste. Characterization of the co-pyrolysis process was carried out both by thermogravimetric-mass spectrometric (TG-MS) analysis, and by reactor tests, using a lab-scale batch reactor equipped with a gas chromatograph for analysis of the evolved gas phase (Py-GC).Due to the presence of clay, two main effects were observed in the instrumental characterization of the process. Firstly, the clay surface catalyzed the pyrolysis reaction of the sludge, and secondly, the release of water from the clay, at temperatures of approx. 450-500 °C, enhanced gasification of part of carbon residue of the organic component of sludge following pyrolysis.Moreover, the solid residue remaining after pyrolysis process, composed of the inorganic component of sludge blended with clay, is characterized by good features for possible disposal by vitrification, yielding a vitreous matrix that immobilizes the hazardous heavy metals present in the sludge.     

Rheological Studies of Microfibrillar Cellulose Water Dispersions

The rheological behaviour of microfibrillar cellulose (MFC) water dispersions has been investigated. For the first time a detailed study of shear dependent viscosity at low and high shear rate is presented. A peculiar time dependent behaviour measured in the area between 0 and 1000 s⁻¹ was identified. The study shows a hysteresis loop in the shear rate–viscosity relationship at low shear rate. Additional time dependent shear rate measurements were performed, and a hypothesis for a mechanism of interaction and formation of a fibrils network was suggested. Higher temperature caused lower viscosity values, and this difference was increased at higher shear rate values. Oscillatory measurements showed how the closeness of the fibrils helps network creations. Data obtained from high shear measurements showed that 1% MFC water dispersions had a dilatant behaviour at ultra high shear rates with values increasing from 120 to 300 Pa s in the area between 180,000 and 330,000 s⁻¹ .     

Biologic impact on the coastal belt of the province of Venice (Italy,Northern Adriatic Sea): preliminary analysis for the characterization of the bathing water profile

Background, aim and scope  

This paper presents a preliminary study of the water profile with reference to microbiological parameters, required by Directive 2006/07/EC (European Community 2006) concerning the management of bathing water quality, in the coastal belt of the Province of Venice (Italy, Northern Adriatic Sea). A historical database has been implemented with monitoring data for the period 2000–2006 (data on rivers, bathing and marine coastal waters and on the characterization of Wastewater Treatment Plant (WWTP) discharges) from the institutional activity of Veneto Regional Environmental Prevention and Protection Agency (ARPAV). An integrated areal analysis for the microbiological investigation of homogeneous stretches along the coast of the Province of Venice was performed for a preliminary characterization of the bathing water profile considering water quality status and existing pressure sources.     

Insecticidal activity and fungitoxicity of plant extracts and components of horseradish (Armoracia rusticana) and garlic (Allium sativum)

To avoid environmental pollution and health problems caused by the use of traditional synthetic pesticides, there is a trend to search for naturally occurring toxicants from plants. Among the compounds discussed for anti-fungal and insecticidal activity, the natural extracts from garlic and horseradish have attracted considerable attention. The objective of this study is to determine the insecticidal and anti-fungal activity of Armoracia rusticana and Allium sativum L. extracts against larvae of Aedes albopictus (Skuse) and some pathogenic fungi. For the insecticidal test, horseradish and garlic extracts were prepared from fresh plants (cultivated in Emilia Romagna region) in a solution of ethanol 80 % and the two different solutions were used at different concentrations (for the determination of the lethal dose) against the fourth instar mosquito's larvae. The fungicidal test was carried out by the agar plates technique using garlic and horseradish extracts in a 10 % ethanol solution against the following organisms: Sclerotium rolfsii Sacc., Trichoderma longibrachiatum, Botrytis cinerea Pers., Fusarium oxysporum Schlecht. and Fusarium culmorum (Wm. G. Sm.) Sacc. The first results demonstrated that the horseradish ethanol extracts present only a fungistatic activity against Sclerotium rolfsii Sacc., Fusarium oxysporum Schlecht. and F. culmorum (Wm.G. Sm) Sacc. while garlic extracts at the same concentration provided a good fungicidal activity above all against Botrytis cinerea Pers. and S. rolfsii. A. rusticana and A. sativum preparations showed also an interesting and significant insecticidal activity against larvae of A. albopictus, even if horseradish presented a higher efficacy (LC?? value of 2.34 g/L), approximately two times higher than garlic one (LC?? value of 4.48 g/L).