Flood monitoring in a semi-arid environment using spatially high resolution radar and optical data

The geographic term "Niger Inland Delta" stands for a vast plain of approximately 40,000 km(2), which is situated in the western Sahel (Republic of Mali). The Inland Delta is affected by yearly inundation through the variable water levels of the Niger-Bani river system. Due to a good availability of (surface) water, the ecosystem at the Niger Inland Delta serves as resting place stop-over for many migrating birds and other wildlife species as well as economic base for farmers and pastoral people. To foster the sustainable usage of its natural resources and to protect this natural heritage, the entire Niger Inland Delta became RAMSAR site in 2004. This paper aims to test to which extent texture analysis can improve the quality of flood monitoring in a semi-arid environment using spatially high resolution ASAR imaging mode data. We found the Gray Level Dependence Method (GLDM) was most suitable proceeding for our data. Several statistical parameters were calculated via co-occurrence matrices and were used to classify the images in different gradation of soil moisture classes. In a second step we used additional information from spatially high resolution optical data (ASTER) to improve the separability of open water areas from moisture/vegetated areas.     

Which compounds contribute most to elevated airborne exposure and corresponding health risks in the Western Balkans?

A majority of ongoing monitoring of persistent organic pollutants (POPs) is currently focused on chemicals emphasized in the Stockholm Convention. Quantitative detection of other substances (especially those with numerous anthropogenic sources such as polyaromatic hydrocarbons (PAHs)) is, however, also needed since their concentrations are usually several orders of magnitude higher. A goal of this study was to determine how various groups of compounds contribute to total human health risks at the variety of sampling sites in the region of Western Balkan. Distribution of the risks between the gas and particulate phases was also addressed. Results showed that inhalation exposure to organochlorine pesticides (OCPs) does not represent a significant risk to humans, while polychlorinated biphenyls (PCBs) re-volatilized to the atmosphere from contaminated soils and buildings can pose a problem. PCB evaporation from primary sources (currently used PCB-filled transformers or non-adequate storage facilities) generally resulted in much higher atmospheric concentrations than evaporation from the secondary sources (soils at the sites of war destructions). A majority of the human health risks at the urban sites were associated with PAHs. Between 83 and 94% of the cumulative risk at such sites was assigned to chemicals sorbed to particles, and out of it, PAHs were responsible for 99%.     

Use and knowledge of fuelwood in three rural caatinga (dryland) communities in NE Brazil

The woody species known, used, and preferred as fuelwood were examined in three rural communities within the county of Soledade, Paraíba State, NE Brazil. Ethnobotanical information was collected using semi-structured interviews with more than 90% of the local households (55 adult residents; 31 women, and 24 males). The interviewees cited 36 plant species as fuelwoods, distributed among 30 genera and 15 families, in addition to two unidentified plants. The plant families represented by the largest numbers of species were Euphorbiaceae, Anacardiaceae, Mimosaceae, Caesalpiniaceae, Sapotaceae, and Fabaceae. The species Caesalpinia pyramidalis Tul. (“catingueira”) was cited with the greatest frequency in all three communities. Within the communities we found significant differences on the number of plants cited and actually used (p < 0.05), indicating that the residents knew more fuelwood species than they effectively harvest. The different distances from the communities to the urban centers were not related to differences on the use or the size of the stocks of fuelwood. Additionally, the study revealed that the communities examined still maintain a significant knowledge of the use of energy-providing plants in spite of the widespread use of liquefied petroleum gas (LPG). Readers should send their comments on this paper to: BhaskarNath@aol.com within 3 months of publication of this issue.     

Assessment of the interrelation between photooxidation and biodegradation of selected polyesters after artificial weathering

Three commercially available biodegradable polymers, two different aromatic-aliphatic copolyesters and polylactic acid, intended for the fabrication of agricultural mulching films, in addition to other applications, were subjected to a series of tests with the aim of studying the relationship between their photooxidation and biodegradation. Photooxidation resulted in the rearrangement of polymeric chains, in the case of both copolyesters the events led to polymeric chain crosslinking and the formation of insoluble polymeric gel. The tendency was significantly more pronounced for the copolyester with the higher content of the aromatic constituent. As regards polylactic acid photochemical reactions were not accompanied by crosslinking but instead provoked chain scissions. A biodegradation experiment showed that, despite marked structural changes, the extent of photooxidation was not the decisive factor, which significantly modified the rate of biodegradation in all three materials investigated. The specific surface area of the sample specimens was shown to be more important.     

Levels and seasonal variations of organochlorine pesticides in urban and rural background air of southern Ghana

Urban, suburban and rural background air samples were collected in southern Ghana in 2008 employing polyurethane foam disc passive air samplers (PAS). PAS were analysed for organochlorine pesticides (OCPs), namely hexachlorocyclohexanes (α-, β-, γ- and δ-hexachlorocyclohexane), dichlorodiphenyltrichloroethane including metabolites (o,p'- and p,p'-DDT, DDE and DDD), hexachlorobenzene, pentachlorobenzene, aldrin, dieldrin, endrins (endrin, endrin aldehyde and endrin ketone), isodrin, heptachlors (heptachlor, heptachlor epoxide A and heptachlor epoxide B), chlordanes (α-, β-chlordane, oxychlordane and trans-nonachlor), endosulfans (α- and β-endosulfan and endosulfan sulphate), methoxychlor and mirex using a gas chromatograph coupled to a mass spectrometer. The levels of OCPs ranged for the individual pesticides from below limit of quantification to 750 pg m(-3) (for α-endosulfan), and current agricultural application seemed to be the main primary source of most abundant pesticides. Re-volatilization of previously used pesticides from contaminated soils could not be ruled out either as potential secondary source of contamination, especially in warm and dry seasons and periods of intensive agricultural activities. Higher atmospheric concentrations were observed in November and December during the dry season compared to lower concentrations observed in June, July and August when the country experiences heavy rains. The highest seasonal variation was observed for currently used pesticides as α-endosulfan. A p,p'-DDT/p,p'-DDE ratio suggested recent inputs of fresh technical DDT.     

Assessment of heterogeneity of metal composition of fine particulate matter collected from eight U.S. counties using principal component analysis

The main objectives of this study are to (1) characterize chemical constituents of particulate matter (PM) and (2) compare overall differences in PM collected from eight US. counties. This project was undertaken as a part of a larger research program conducted by the Johns Hopkins Particulate Matter Research Center (JHPMRC). The goal of the JHPMRC is to explore the relationship between health effects and exposure to ambient PM of differing composition. The JHPMRC collected weekly filter-based ambient fine particle samples from eight US. counties between January 2008 and January 2010. Each sampling effort consisted of a 5-6-week sampling period. Filters were analyzed for 25 metals using inductively coupled plasma mass spectrometry (ICP-MS). Overall compositional differences were ranked by principal component analysis (PCA). The results showed that weekly concentrations of each element varied 3-40 times between the eight counties. PCA showed that the first five principal components explained 85% of the total variance. The authors found significant overall compositional differences in PM as the average of standardized principal component scores differed between the counties. These findings demonstrate PCA is a useful tool to identify the differences in PM compositional mixtures by county. These differences will be helpful for epidemiological and toxicological studies to help explain why health risks associated with PM exposure are different in locations with similar mass concentrations of PM.     

Water quality assessment of the Tubarão River through chemical analysis and biomarkers in the Neotropical fish Geophagus brasiliensis

The Tubarão River rises in Santa Catarina, Brazil, and has been historically affected by coal mining activities around its springhead. To evaluate its water conditions, an investigation regarding a possible decontamination gradient associated with the increased river flow toward the estuary, as well as the influence of seasonality over this gradient was performed through a series of biomarkers (vitellogenin, comet assay, lipid peroxidation, protein carbonylation, gluthatione, gluthatione S-transferase, acetylcholinesterase, light microscopy in liver, and scanning electron microscopy in gills) and chemical analysis (polycyclic aromatic hydrocarbons (PAHs) in bile and metal analysis in sediment) in the cichlid Geophagus brasiliensis. Two collections (summer and winter) were made in four distinct sites along the river, while sediments were sampled between those seasons. As expected, the contamination linked exclusively to mining activities was not observed, possibly due to punctual inputs of contaminants. The decontamination gradient was not observed, although seasonality seemed to have a critical role in the responses of biomarkers and availability of contaminants. In the summer, the fish presented higher histopathological damages and lower concentrations of PAHs, while in the winter they showed both higher genetic damage and accumulation of PAHs. The Tubarão suffers impacts from diverse activities, representing health risks for wild and human populations.     

Managing United States Public Lands in Response to Climate Change: A View From the Ground Up

Federal land managers are faced with the task of balancing multiple uses and goals when making decisions about land use and the activities that occur on public lands. Though climate change is now well recognized by federal agencies and their local land and resource managers, it is not yet clear how issues related to climate change will be incorporated into on-the-ground decision making within the framework of multiple use objectives. We conducted a case study of a federal land management agency field office, the San Juan Public Lands Center in Durango, CO, U.S.A., to understand from their perspective how decisions are currently made, and how climate change and carbon management are being factored into decision making. We evaluated three major management sectors in which climate change or carbon management may intersect other use goals: forests, biofuels, and grazing. While land managers are aware of climate change and eager to understand more about how it might affect land resources, the incorporation of climate change considerations into everyday decision making is currently quite limited. Climate change is therefore on the radar screen, but remains a lower priority than other issues. To assist the office in making decisions that are based on sound scientific information, further research is needed into how management activities influence carbon storage and resilience of the landscape under climate change.     

Removal of phthalates from aqueous solution by different adsorbents: a short review

This work presents a short review of adsorptive materials proposed and tested for removing phthalates from an aqueous environment. The objective is not to present an exhaustive review of all the types of adsorbents used, but to focus on selected types of "innovative" materials. Examples include modified activated carbon, chitosan and its modifications, β-cyclodextrin, and specific types of biomass, such as activated sludge from a wastewater treatment plant, seaweed and microbial cultures. Data from the literature do not confirm the existence of a broad-spectral adsorbent with high sorption efficiency, low production costs and environmentally friendly manufacture. According to the coefficients of Freundlich's isotherm, the most promising adsorbent of those mentioned in this work appears to be the biomass of activated sludge, or extracellular polysaccharides extracted from it. This material benefits from steady production, is cheap and readily available. Nevertheless, before putting it in practice, the treatment and adaptation of this raw material has to be taken into consideration.     

The use of physiological characteristics for comparison of organic compounds phytotoxicity

The influence of intact (FLT) and photomodified (phFLT) fluoranthene (0.05, 0.5 and 5 μmol l⁻¹) and herbicide Basagran (5, 20, 35 and 50 nmol l⁻¹) on the germination, growth of seedlings and photosynthetic processes in pea plants (Pisum sativum L., cv. Garde) was investigated. The germination was significantly inhibited already by the lowest concentration (0.05 μmol l⁻¹) of FLT and phFLT, while Basagran caused inhibition only in higher concentrations (35 and 50 nmol l⁻¹). The growth of roots was significantly inhibited by higher concentration 5 μmol l⁻¹ of both FLT and phFLT and the shoot of seedlings was significantly influenced only by photomodified form. The length of root and shoot was inhibited already by concentration 5 nmol l⁻¹ of Basagran. Organic compounds applied on chloroplasts suspension influenced primary photochemical processes of photosynthesis. In chlorophyll fluorescence parameters, the significant increase of F₀ values and the decrease of F_V/F_M and Φ_II values by application of FLT (0.5 and 5 μmol l⁻¹) and phFLT (0.05, 0.5 and 5 μmol l⁻¹) was recorded. The maximum capacity of PSII (F_V/F_M) was influenced by the highest (50 nmol l⁻¹) and the effective quantum yield of PSII (Φ_II) already by the lowest (5 nmol l⁻¹) concentration of Basagran. Hill reaction activity decreased and was significantly inhibited by higher concentration (0.5 and 5 μmol l⁻¹) of FLT and phFLT and already by the lowest concentration (5 nmol l⁻¹) of Basagran.