Pesticides in the Rhône river delta (France): basic data for a field-based exposure assessment

The pesticide concentration levels flowing into paddy fields and surrounding lagoons of the Rh?ne river delta were investigated over a period of 6 months in 2004. Water samples were collected at the outlets of the major ditches and in the lagoons in order to study the seasonal variation in pesticide concentrations and the spatial contamination profile. Twenty four pesticides were monitored, mainly herbicides and insecticides. Rice pesticides accounted for 90% of the detection rates while the pesticides transported by the Rh?ne river water dissolved phase only accounted for 10%. Pretilachlor, oxadiazon, MCPA and bentazone herbicides were found at the highest frequencies into the effluent waters of ditches with maximum concentration levels of 1.2, 0.8, 2.5 and 1.6 microg/L, respectively. Only one insecticide, tebufenozide, was sporadically detected at a maximum concentration level of 0.12 microg/L. There were two main peaks of contamination. The first one in April corresponded to the use of pre-emergence herbicides (oxadiazon and pretilachlor) and the second one in June was related to the post-emergence herbicides (MCPA and bentazone). These concentration peaks were well correlated with the pesticide application period time and rapid pesticide transfer (1-2 weeks) from fields to lagoons were observed. Increased loads of the pre-emergence herbicides were induced by the specific management of paddy fields which includes water emptying of fields before and after rice seeding. Pesticide dissipation into the lagoons occurred very quickly and the duration of the exposure of non-target aquatic organisms to high pesticide concentrations (in total a few microg/L level) was no longer than 2 weeks. According to the physico-chemical properties of the chemicals, contrasting results were observed when studying the spatial variation in pesticide concentrations through the lagoons. The concentrations of bentazone and MCPA, two substances with high phototransformation abilities, quickly decreased between the ditches and the lagoons while the oxadiazon and pretilachlor concentrations were more homogeneous.     

Effects of chemical pollution on the activities of hepatic xenobiotic metabolizing enzymes in fish from the River Rh?ne

Polychlorobiphenyl (PCBs) levels and hepatic xenobiotic metabolizing enzyme activities were measured in fish from three locations of the River Rh?ne to study the consequences of a constant loading of PCBs from a PCB incineration plant. Our results show that levels of PCBs and enzyme activities were higher in fish living downstream from the plant than in fish from two locations upstream, suggesting enzyme induction by PCBs (known to be potent inducers in laboratory conditions). Enzyme activities were studied in spring and autumn in three species: nase (Chondrostoma nasus), roach (Rutilus rutilus) and grayling (Thymallus thymallus). Induction was observed for three cytochrome P-450-dependent monooxygenase activities (MO), i.e. 7-ethoxyresorufin O-deethylase (EROD), aryl hydrocarbon hydroxylase (AHH) and 7-ethoxycoumarin O-deethylase (ECOD). There was a close correlation between EROD and AHH activities (for all species). Glutathione S-transferase activities were also shown to be related to the PCB levels. Conversely, cytochrome P-450 content and benzphetamine N-demethylase activity were not "PCB level-dependent". This study clearly demonstrates a close relationship between PCB contamination and MO activities in fish from the field and thus clearly emphasizes the interest in MO as a monitoring tool for estimating water quality.     

Reconsideration of Village Plan for the Pearl River Delta Region in the Context of Social Transformation——A Case Study of Guangzhou Zengcheng Events

2007年以来珠三角等主要城市先后推进的辖区内村庄规划,至今已经基本完成,尽管实现了城乡统筹发展的目标,但仍然产生较多的问题.在社会转型的背景中分析上述问题,明确当前社会组织转型滞后与社会结构转型,由此引起空间转型滞后社会转型;分析村庄规划编制理论与实践以及在社会转型背景中,村庄规划不仅仅是村庄内部的乡规民约,城市和农村在土地利用方面的协议,城市帮扶农村的平台,还应突出公共服务的均等化,协调好当地在籍人口与外来人口的利益诉求.     

Mercury and flooding cycles in the Tapajós River basin, Brazilian Amazon: the role of periphyton of a floating macrophyte (Paspalum repens)

Methylmercury (MeHg) increases mercury (Hg) toxicity and is biomagnified in the trophic chain contaminating riverine Amazon populations. Freshwater macrophyte roots are a main site of Hg methylation in different Brazilian environments. Paspalum repens periphyton was sampled in four floodplain lakes during the dry, rainy and wet seasons for measurement of total Hg (THg), MeHg, Hg methylation potentials, %C, %N, δ¹³C, δ¹⁵N and bacterial heterotrophic production as ³H-leucine incorporation rate. THg concentration varied from 67 to 198 ng/g and the potential of Me²⁰³Hg formation was expressive (1-23%) showing that periphyton is an important matrix both in the accumulation of Hg and in MeHg production. The concentration of MeHg varied from 1 to 6 ng/g DW and was positively correlated with Me²⁰³Hg formation. Though methylmercury formation is mainly a bacterial process, no significant correlation was observed between the methylation potentials and bacterial production. The multiple regressions analyses suggested a negative correlation between THg and %C and %N and between methylation potential and δ¹³C. The discriminant analysis showed a significant difference in periphyton δ¹⁵N, δ¹³C and THg between seasons, where the rainy season presented higher δ¹⁵N and the wet period lighter δ¹³C, lower THg values and higher Me²⁰³Hg formation. This exploratory study indicates that the flooding cycle could influence the periphyton composition, mercury accumulation and methylmercury production.     

Changes in the location and function of small water bodies in the upper Sanna River catchment—case study (SE Poland)

The article summarises the results of analyses of temporal and spatial changes in the location of small water bodies in the upper Sanna River catchment between the fifteenth and twenty-first centuries. The investigations were conducted on historical sources and cartographic data using GIS tools and inventory files. Natural (location of springs, groundwater depth, geomorphology of valleys), anthropogenic factors (quarries, excavations) and historical determinants of construction of the water reservoirs are presented. Additionally, changes in the economic (fish farming, mills), defence and industrial (paper and steel mills, bloomeries, fulleries) functions of the water bodies have been analysed. The changes in the functions of the water bodies were often influenced by the changing ownership. The results have application significance on a local and regional scale.     

Bacterial immobilization and oxidation of arsenic in acid mine drainage (Carnoulès creek,France)

The acid waters (pH=2.73-3.37) originating from the Carnoulès mine tailings contain high dissolved concentrations of arsenic (1-3.5 mmol l(-1)) and iron (20-40 mmol l(-1)). At the outlet, arsenite predominates. During the first 30 m of downflow, 20-60% is removed by coprecipitation with Fe(III). This process results from bacterially mediated As- and Fe-oxidation. The precipitation rates in the creek depend on the oxygen concentration in spring water and are lower during the dry summer period when the anoxic character of the spring water inhibits the activity of oxidizing bacteria. Ex situ experiments show that the presence of bacteria-rich precipitates increases the As- and Fe-removal rates. Three strains of bacteria promoting the oxidation of As have been isolated, and two of them have the characteristics of Thiomonas ynys1. The third strain, which is not identified yet, also catalyzes the oxidation of Fe.     

Use of green roofs to solve storm water issues at the basin scale – Study in the Hauts-de-Seine County (France)

At the building scale, green roof has demonstrated a positive impact on urban runoff (decrease in the peak discharge and runoff volume). This work aims to study if similar impacts can be observed at a basin scale. It is particularly focused on the possibility to solve some operational issues caused by storm water.

For this purpose, a methodology has been proposed. It combines: a method to estimate the maximum roof area that can be covered by green roof, called green roofing potential, and an urban rainfall-runoff model able to simulate the hydrological behaviour of green roof.

This methodology was applied to two urban catchments, one affected by flooding and the other one by combined sewage overflow. The results show that green roof can reduce the frequency and the magnitude of such problems depending on the covered roof surface. Combined with other infrastructures, they represent an interesting solution for urban water management.     

Arsenic oxidation and bioaccumulation by the acidophilic protozoan, Euglena mutabilis, in acid mine drainage (Carnoulès, France)

In the acid stream (pH 2.5-4.7) originating from the Carnoulès mine tailings, the acidophilic protozoan Euglena mutabilis grows with extremely high sulfate (1.9-4.9 g/l), iron (0.7-1.7 g/l) and arsenic concentrations (0.08-0.26 g/l). Strong variations in flow rate and high sulfate concentrations (up to 4.9 g/l) have been registered in early winter and might be the reason for the reduction in cell number of the protozoan from October to December 2001. No relation was established between arsenic concentration and/or speciation and abundance of the protozoan in the stream. Arsenite, which is the most toxic form, predominates in water. The oxidation of arsenite to arsenate occurred within a few days in laboratory experiments when E. mutabilis was present in Reigous Creek water and synthetic As(III)-rich culture medium. Methylated compounds (MMA, DMA) were not identified in the culture media. The protozoan bioaccumulated As in the cell (336 +/- 112 microg As/g dry wt.) as inorganic arsenite (105 +/- 52 microg As/g dry wt.) and arsenate (231 +/- 112 microg As/g dry wt.). Adsorption of As at the cell surface reached 57 mg/g dry wt. in the As(V) form for E. mutabilis grown in 250 mg/l As(III) synthetic medium. Both intracellular accumulation and adsorption at the cell surface increased for increasing As(III) concentration in the medium but the concentration factor in the cell relative to soluble As decreased.     

Regression analyses for the minimum intensity-duration conditions of continuous rainfall for mudflows triggering in Yan’an,northern Shaanxi (China)

An empirical minimum intensity-duration (I-D) condition of continuous rainfall for mudflows triggering is proposed for Yan’an, northern Shaanxi, China, where rainfall-induced mudflows occur frequently. Adopting the quantile-regression method, a program was built using R programming language and statistical computing environment, and 175 continuous rainfall records were analyzed objectively. The 35th percentile regression line was determined as the minimum I-D condition of continuous rainfall that can potentially trigger mudflows within the duration interval of 24–336 h, where I is measured in millimeters per hour and D in hours. Comparison of the minimum I-D condition of continuous rainfall determined by this study with those rainfall I-D thresholds developed for the world and other regions reveals that lower rainfall intensity has the potential to trigger mudflows in the Yan’an district, which proves the necessity of defining regional minimum rainfall I-D conditions and site-specific operational rainfall I-D thresholds for mudflows triggering in Yan’an.     

Typological classification of clayey raw materials for ceramics manufacture, in the Tábua region (central Portugal)

Mapping of clay resources in the Cenozoic deposits of the Tábua region (central Portugal) has been carried out, together with the chemical, mineralogical and technological characterization of seventeen clay samples. The study was undertaken to relate the lithostratigraphic units and the typology of raw materials with regard to the manufacture of ceramics. The sedimentary succession comprises two units with different suitability for the manufacture of ceramics: an upper unit, with clays that present technological restrictions; and a lower unit with a much greater potential. A small set of parameters has been identified which differentiate the typological units. These parameters allow a realistic estimation to be made of the ceramic properties of any clay layer sampled in the study area. It is anticipated that with minor field work and sampling, the typological column can also be used in adjacent areas.     

Integral assessment of pollution in the Suquía River (Córdoba, Argentina) as a contribution to lotic ecosystem restoration programs

The Suquía River lower-middle basin (Córdoba, Argentina) is subject to a strong anthropic impact because it receives pollutants from different sources (industries, wastewaters, heavy traffic, agricultural land use, etc.) We have assessed the degree of watershed degradation of Suquía River lower-middle sections through the analysis of different ecosystem compartments (air, water, riparian soil, sediments and biota), in order to provide useful data to be considered in future river restoration programs. Four study sites were selected along the river (La Calera city, Córdoba city, Corazón de María village and Río Primero city) which were sampled during the low- and high-water flow periods. We analyzed: a) chemical and physical characteristics of water, sediments, and riparian soil; b) heavy metal content of water and sediments, and c) semi-volatile organic compounds in air. Besides, pollutant bioindicators such as fish assemblages, lichens (Usnea amblyoclada), vascular plants (Tradescantia pallida), and microorganisms (fecal coliform and Escherichia coli) were used to further assess the status of the river. All analyzed ecological compartments were affected by water pollution, particularly, fish assemblages, sediments and riparian soils by heavy metal and coliform bacteria. Moreover, we detected a possible contribution of sulfur and a high pollutant content in air that merit further research about other air-water exchanges. Accordingly, we strongly suggest that an action to restore or remediate the anthropic effect on the Suquía River be extended to all possible compartments along the river.     

Chemical–mineralogical characterisation as useful tool in the assessment of the decay of the Mesola Castle (Ferrara,Italy)

The Mesola Castle and its Portico (16th century) rises on the right side branch of the River Po Delta in the eastern part of Ferrara province (Italy). Bricks, mortars and plasters from the Castle’s Portico were characterised by optical microscopy, X-ray fluorescence, X-ray diffraction and scanning electron microscopy/energy-dispersive X-ray spectrometers. This masonry is affected by efflorescence and sub-efflorescence, and mineralogical analysis, together with scanning electron microscopy observations, assisted to define the damaging products. Structures built in coastal environments are subject to sea weathering which cause substantial damages mainly due to the presence of salts. These could attack the building materials: (a) by penetrating from the ground through dampness; (b) carried by the wind in the form of salt spray; (c) due to occasional or recurrent flooding; (d) caused by the use of marine water during the preparation of mortar. For these reasons an integrated study approach involving chemical–mineralogical analysis and assessment of the environmental conditions is a useful tool to better define the causes of building materials deterioration.     

Instituting order: the limitations of Nasser's post-colonial planning visions for Cairo in the case of the indigenous quarter of Bulaq (1952–1970)

This paper investigates the limitations of post-colonial planning practices that aimed to modernize Cairo's urban spaces during Gamal Abdel Nasser's rule (1952–1970). Following the Free Officers revolution of 1952, ambition to display urban order through forceful change in the city's built environment was in action. Nasser's visions of modernity were explicit in a series of attempts to reshape several prime locations in central Cairo, which included the old traditional waterfront quarter, in Bulaq Abul Ela. An analysis of the Bulaq planning scheme drafted in 1966 reveals insights into how notions of order were spatialized to integrate with Cairo's complex urban fabric. The official plans to regularize Bulaq also strongly demonstrate how this was a top-down, centralized process in terms of governance, with full utilization of state resources, namely the military and the media. From a wider perspective, planning practices under Nasser demonstrated an evident break with the past to eliminate memories of colonization and disorder. Drawing on original resources, archival material, meeting minutes and maps of this historical but dilapidated quarter of Cairo, this paper gives an insight into how Nasser's government attempted to convey a sense of order in a revolutionary country without, however, having an understanding of order as a coherent, multi-layered and sequential process of change.     

Pattern recognition techniques for the evaluation of spatial and temporal variations in water quality. A case study: Suquía River Basin (Cordoba-Argentina)

We report a comparative study using three different chemometric techniques to evaluate both spatial and temporal changes in Suquía River water quality, with a special emphasis on the improvement obtained using discriminant analysis for such evaluation. We have monitored 22 parameters at different stations from the upper, middle, and beginning of the lower river basin during at least two years including 232 different samples. We obtained a complex data matrix, which was treated using the pattern recognition techniques of cluster analysis (CA), factor analysis/principal components (FA/PCA). and discriminant analysis (DA). CA renders good results as a first exploratory method to evaluate both spatial and temporal differences, however it fails to show details of these differences. FA/PCA needs 13 parameters to point out 71% of both temporal and spatial changes, consequently data reduction from FA/PCA in this case is not as considerable as expected. However, FA/PCA allows to group the selected parameters according to common features as well as to evaluate the incidence of each group on the overall change in water quality, specially during the analysis of temporal changes. DA technique shows the best results for data reduction and pattern recognition during both temporal and spatial analysis. DA renders an important data reduction using 6 parameters to afford 87% right assignations during temporal analysis. Besides, it uses only 5 parameters to yield 75% right assignations during the spatial analysis of four different basin areas. DA allowed us to greatly reduce the dimensionality of the starting data matrix, pointing out to a few parameters that indicate the biggest changes in water quality as well as variation patterns associated with seasonal variations, urban run-off, and pollution sources, presenting a novel approach for water quality assessments.     

The Impact of the Mg(II)/Fe(III) Ratio in the Composition of Layered Double Hydroxides for the Removal of Phosphate–Ions from Water Media

The results of the impact of the [Mg(II)]/[Fe(III)] as part of layered double hydroxides on their sorption capacity with respect to phosphate-ions are presented. It is shown that the most effective for the removal of the given anions from water media within the range pH 3–9 are calcined forms of sorbents being studied with the [Mg(II)]/Fe(III)] 2 : 1 and 3 : 1. Maximum values of adsorption constitute respectively 90.9 and 91.7 mg/g.     

Building Collective Knowledge Through Design: The Making of the Contrada Nicolò Riparian Garden Along the Simeto River (Sicily,Italy)

Insurgent movements advocating environmental protection have garnered attention from design disciplines for their capacity to envision sustainable powerful transformations of human environments. In the last twenty years, the recognition of this potential has entered into research agendas, which have mainly focused on explaining through case studies how these phenomena have been able to affect institutional planning efforts in relation to environmental issues. Following a Participatory Action Research approach, this article presents a design experience carried out by a partnership established between a grass-roots association and university researchers in the Simeto River Valley (Sicily, Italy). It shows how design research techniques, borrowed from place making and community design approaches, can be used as instruments to promote goals of community-based organisations and advance their capacity in conceiving actions to transform local environments.     

Isotopic identification of the sources of lead contamination for white storks (Ciconia ciconia) in a marshland ecosystem (Doñana,S.W. Spain)

White storks (Ciconia ciconia) fed in contaminated waters resulting from the Aznacollar acid mining-sludge spillage into the R. Guadiamar, which feeds the eastern flank of the Guadalquivir marshes (Do?ana), S.W. Spain. The sludge was rich in a range of toxic elements, and in organic pollutants such as the aromatic amines. Storks did not exhibit elevated metals in their blood immediately following the accident, but chick blood collected the year following the accident showed genotoxic damage compared to the controls. In this study lead isotope analysis was used to assess if the storks had ingested sludge-derived contaminants. The sludge lead isotope ratio was distinct from that of the Do?ana sediments. The stork blood lead isotope ratios exactly matched that of the sludge. It was concluded that the storks had ingested sludge-derived contaminants. A detailed study of the lead contamination along the R. Guadiamar and the R. Guadalquivir (of which the Guadiamar is a tributary) was also conducted to place the white stork colony lead exposure in the context of the spatial contamination of the storks' habitat.     

Changes in water quality of the River Frome (UK) from 1965 to 2009: is phosphorus mitigation finally working?

The water quality of the River Frome, Dorset, southern England, was monitored at weekly intervals from 1965 until 2009. Determinands included phosphorus, nitrogen, silicon, potassium, calcium, sodium, magnesium, pH, alkalinity and temperature. Nitrate-N concentrations increased from an annual average of 2.4 mg l^− 1 in the mid to late 1960s to 6.0 mg l^− 1 in 2008-2009, but the rate of increase was beginning to slow. Annual soluble reactive phosphorus (SRP) concentrations increased from 101 μg l^− 1 in the mid 1960s to a maximum of 190 μg l^− 1 in 1989. In 2002, there was a step reduction in SRP concentration (average = 88 μg l^− 1 in 2002-2005), with further improvement in 2007-2009 (average = 49 μg l^− 1), due to the introduction of phosphorus stripping at sewage treatment works. Phosphorus and nitrate concentrations showed clear annual cycles, related to the timing of inputs from the catchment, and within-stream bioaccumulation and release. Annual depressions in silicon concentration each spring (due to diatom proliferation) reached a maximum between 1980 and 1991, (the period of maximum SRP concentration) indicating that algal biomass had increased within the river. The timing of these silicon depressions was closely related to temperature. Excess carbon dioxide partial pressures (EpCO₂) of 60 times atmospheric CO₂ were also observed through the winter periods from 1980 to 1992, when phosphorus concentration was greatest, indicating very high respiration rates due to microbial decomposition of this enhanced biomass. Declining phosphorus concentrations since 2002 reduced productivity and algal biomass in the summer, and EpCO₂ through the winter, indicating that sewage treatment improvements had improved riverine ecology. Algal blooms were limited by phosphorus, rather than silicon concentration. The value of long-term water quality data sets is discussed. The data from this monitoring programme are made freely available to the wider science community through the CEH data portal (http://gateway.ceh.ac.uk/).