Partitioning, sources and variability of regional and local oxidant (OX = O3 + NO2) in a coastal rural area in the southwest of Iberian Peninsula

The purpose of this work is to investigate the behaviour and variability of oxidant levels (OX?=?NO₂?+?O₃), for the first time, in a rural coastal area in the southwest of the Iberian Peninsula, affected by several air masses types. Detailed database (built-up over the years 2008 to 2011, and containing around 500,000 data) from the Atmospheric Sounding Station “El Arenosillo” was used. The observed daily cycles of NO _x and OX were influenced by air masses coming from industrial and urban area. It can be seen that the concentration of OX is made up of a NO _x -independent ‘regional’ contribution (i.e. the O₃ background), and a linearly NO _x -dependent ‘local’ contribution from primary emissions, such as traffic. The local emission is very low in this area. Also, the regional contribution is similar to unpolluted sites and presents seasonal variation, being higher in May. However, our measurements showed that the proportion of OX in the form of NO₂ increases with the increase in NO _x concentration during the day. The higher proportion of NO₂ observed at night must be due to the conversion of NO to NO₂ by the NO?+?O₃ reaction. With regards to the source of the local NO _x -dependent contribution, it may be attributed to industrial emission, or the termolecular reaction 2NO?+?O₂?=?2NO₂, at high-NO _x levels and stagnant air during several days. Finally, we estimated the photolysis rate of NO₂, J _NO2, an important key atmospheric reaction coupled with ozone. We also present surface plots of annual variation of the daily mean NO _x and OX levels, which indicate that oxidants come from transport processes instead of local emissions associated as local photochemistry.     

Multimedia fate modeling and comparative impact on freshwater ecosystems of pharmaceuticals from biosolids-amended soils

This study modeled the impact on freshwater ecosystems of pharmaceuticals detected in biosolids following application on agricultural soils. The detected sulfonamides and hydrochlorothiazide displayed comparatively moderate retention in solid matrices and, therefore, higher transfer fractions from biosolids to the freshwater compartment. However, the residence times of these pharmaceuticals in freshwater were estimated to be short due to abiotic degradation processes. The non-steroidal anti-inflammatory mefenamic acid had the highest environmental impact on aquatic ecosystems and warrants further investigation. The estimation of the solid-water partitioning coefficient was generally the most influential parameter of the probabilistic comparative impact assessment. These results and the modeling approach used in this study serve to prioritize pharmaceuticals in the research effort to assess the risks and the environmental impacts on aquatic biota of these emerging pollutants.     

Determination of anti-anxiety and anti-epileptic drugs in hospital effluent and a preliminary risk assessment

In this study, an analytical methodology was developed for the determination of psycho-active drugs in the treated effluent of the University Hospital at the Federal University of Santa Maria, RS – Brazil. Samples were collected from point A (Emergency) and point B (General effluent). The adopted methodology included a pre-concentration procedure involving the use of solid phase extraction and determination by liquid chromatography coupled to mass spectrometry. The limit of detection for bromazepam and lorazepam was 4.9 ± 1.0 ng L⁻¹ and, for carbamazepine, clonazepam and diazepam was 6.1 ± 1.5 ng L⁻¹. The limit of quantification was 30.0 ± 1.1 ng L⁻¹, for bromazepam, clonazepam and lorazepam; for carbamazepine was 50.0 ± 1.8 ng L⁻¹ and was 40.0 ± 1.0 ng L⁻¹ for diazepam. The mean concentrations in the Emergency and General effluent treated currents were as follows: for bromazepam, 195 ± 6 ng L⁻¹ and 137 ± 7 ng L⁻¹; for carbamazepine, 590 ± 6 ng L⁻¹ and 461 ± 10 ng L⁻¹; for diazepam, 645 ± 1 ng L⁻¹ and 571 ± 10 ng L⁻¹; for lorazepam, 96 ± 7 ng L⁻¹ and 42 ± 4 ng L⁻¹; and for clonazepam, 134 ± 10 ng L⁻¹ and 57 ± 10 ng L⁻¹. A preliminary risk assessment was conducted: carbamazepine and diazepam require considerable attention owing to their environmental toxicity. The occurrence of these psychoactive-drugs and the environmental risks that they pose demonstrated the need for a more efficient treatment system. As far we are aware, there have been no comparable studies to this on the hazards of hospital effluents in Brazil, and very few that have carried out a risk assessment of psycho-active drugs in hospital effluent in general.     

Removal of famoxadone,fluquinconazole and trifloxystrobin residues in red wines: Effects of clarification and filtration processes

The effects of six clarification agents [egg albumin, blood albumin, bentonite + gelatine, charcoal, polyvinylpolypyrrolidine (PVPP) and silica gel] on the removal of residues of three fungicides (famoxadone, fluquinconazole and trifloxystrobin) applied directly to a racked red wine, elaborated from Monastrell variety grapes from the D.O. Region of Jumilla (Murcia, Spain) were studied. The clarified wines were filtered with 0.45 μ m nylon filters to determine the influence of this winemaking process in the disappearance of fungicide residues. Analytical determination of fluquinconazole and trifloxystrobin was performed by gas chromatography with electron captor detector (ECD), while that of famoxadone using an HPLC equipped with a diode array detector (DAD). Generally, trifloxystrobin is the fungicide that is the lowest persistent one in wines, except in the egg albumin study whereas, the most persistent one is fluquinconazole. The elimination depends on the nature of the active ingredient, though the water stability in the presence of light within it has more influence than the solubility and polarity of the product itself. The most effective clarifying agents were the charcoal and PVPP. The silica gel and bentonite plus gelatine were not enough to reduce considerably the residual contents in the wine clarified with them. In general terms, filtration is not an effective step in the elimination of wine residues. The greatest removal after filtration is obtained in wines clarified with egg albumine and bentonite plus gelatine, and the lowest in those clarified with PVPP.     

Fluxes and pools of methane in wetland rice soils with varying organic inputs

Measurements of methane emission rates and concentrations in the soil were made during four growing seasons at the International Rice Research Institute in the Philippines, on plots receiving different levels of organic input. Fluxes were measured using the automated closed chambers system (total emission) and small chambers installed between plants (water surface flux). Concentrations of methane in the soil were measured by collecting soil cores including the gas phase (soil-entrapped methane) and by sampling soil solution in situ (dissolved methane). There was much variability between seasons, but total fluxes from plots receiving high organic inputs (16–24 g CH₄ m^–2) always exceeded those from the low input plots (3–9 g CH₄ m^–2). The fraction of the total emission emerging from the surface water (presumably dominated by ebullition) was greater during the first part of the season, and greater from the high organic input plots (35–62%) than from the low input plots (15–23%). Concentrations of dissolved and entrapped methane in the low organic input plots increased gradually throughout the season; in the high input plots there was an early-season peak which was also seen in emissions. On both treatments, periods of high methane concentrations in the soil coincided with high rates of water surface flux whereas low concentrations of methane were generally associated with low flux rates.     

Global burned-land estimation in Latin America using MODIS composite data.

This paper presents results of the AQL2004 project, which has been develope within the GOFC-GOLD Latin American network of remote sensing and forest fires (RedLatif). The project intended to obtain monthly burned-land maps of the entire region, from Mexico to Patagonia, using MODIS (moderate-resolution imaging spectroradiometer) reflectance data. The project has been organized in three different phases: acquisition and preprocessing of satellite data; discrimination of burned pixels; and validation of results. In the first phase, input data consisting of 32-day composites of MODIS 500-m reflectance data generated by the Global Land Cover Facility (GLCF) of the University of Maryland (College Park, Maryland, U.S.A.) were collected and processed. The discrimination of burned areas was addressed in two steps: searching for "burned core" pixels using postfire spectral indices and multitemporal change detection and mapping of burned scars using contextual techniques. The validation phase was based on visual analysis of Landsat and CBERS (China-Brazil Earth Resources Satellite) images. Validation of the burned-land category showed an agreement ranging from 30% to 60%, depending on the ecosystem and vegetation species present. The total burned area for the entire year was estimated to be 153 215 km2. The most affected countries in relation to their territory were Cuba, Colombia, Bolivia, and Venezuela. Burned areas were found in most land covers; herbaceous vegetation (savannas and grasslands) presented the highest proportions of burned area, while perennial forest had the lowest proportions. The importance of croplands in the total burned area should be taken with reserve, since this cover presented the highest commission errors. The importance of generating systematic products of burned land areas for different ecological processes is emphasized.     

Hydrogeochemical considerations about the origin of groundwater salinization in some coastal plains of Elba Island (Tuscany,Italy)

Several coastal plains of the Elba Island (Marina di Campo, Portoferraio, Schiopparello, Mola, Porto Azzurro and Barbarossa plains) in Tuscany (Italy) were studied to determine the causes of decline in groundwater quality, using major ion chemistry to establish the causes of groundwater salinization. The study demonstrates that salinization of coastal plain alluvial aquifers is not simply linked to seawater intrusion but is also intimately related to inflows from adjacent aquifers. Ionic ratios, correlation graphs and distribution value maps were employed as the means to understand the hydrochemistry of the study areas. The Mg/Cl ratio in particular can be considered a good tracer to distinguish the main salinization processes that control groundwater chemistry. Seawater intrusion only partly determines the chemistry of some groundwaters, which generally belong to a chloride facies where the salinity is derived principally from freshwater–seawater mixing and the participation of cation exchange. Proceeding inland groundwater quality seems to be principally determined by the inflow of Mg, Ca-HCO₃ or Ca, Na-HCO₃ waters formed from the weathering of silicate minerals in adjoining aquifers. Hydrolysis of these minerals is of prime importance in controlling groundwater chemistry in adjacent alluvial plains. The lateral recharge flows introduce water with a different chemical composition and this variable of freshwater recharge changes the hydrochemistry as a result of mixing between two or more waters types. This situation is further complicated when seawater and base exchange reactions participate, due to seawater intrusion.     

A three-isotope approach to disentangling the diet of a generalist consumer: the yellow-legged gull in northwest Spain

The widespread omnivory of consumers and the trophic complexity of marine ecosystems make it difficult to infer the feeding ecology of species. The use of stable isotopic analysis plays a crucial role in elucidating trophic interactions. Here we analysed δ¹⁵N, δ¹³C and δ³⁴S in chick feathers, and we used a Bayesian triple-isotope mixing model to reconstruct the diet of a generalist predator, the yellow-legged gull (Larus michahellis) that breeds in the coastal upwelling area off northwest mainland Spain. The mixing model indicated that although chicks from all colonies were fed with a high percentage of fish, there are geographical differences in their diets. While chicks from northern colonies consume higher percentages of earthworms, refuse constitutes a more important source in the diet of chicks from western colonies. The three-isotope mixing model revealed a heterogeneity in foraging habitats that would not have been apparent if only two stable isotopes had been analysed. Moreover, our work highlights the potential of adding δ³⁴S for distinguishing not only between terrestrial and marine prey, but also between different marine species such as fish, crabs and mussels.     

Assessment of a large watershed in Brazil using Emergy Evaluation and Geographical Information System

Humanity's future depends on the preservation of natural ecosystems that supply resources and absorb pollutants. Rural and urban productions are currently based on chemical products made from petroleum, which are responsible for high negative impacts on the Biosphere. In order to prevent those impacts, efficient public policies seeking for sustainable development are necessary. Aiming to assess the load on the environment (considering the gratuitous contributions of natural systems—a donor's perspective) due to human-dominated process, a scientific tool called Emergy Evaluation has been applied in different production systems, including crops and farms. However, there is still a lack of emergy studies in the context of watersheds, probably due to the difficulty of collecting raw data. The present work aims to carry out an assessment of Mogi-Guaçu and Pardo watershed, through the combined use of Emergy Evaluation and Geographical Information System. The agricultural and natural land uses were considered, while urban areas were excluded. Emergy flows (expressed in seJ ha⁻¹ yr⁻¹) obtained for all agricultural and natural land uses were expanded for the whole watershed and the emergy indices were calculated. The results show that the watershed has: low renewability (%R = 32%); low capture of natural resources through high external economic investment (EYR = 1.86); low dependence on natural resources (EIR = 1.16); and moderate load on the environment (ELR = 2.08). Considering a scenario where sugar-cane crops, orchards and pasture areas are converted from conventional to organic management, watershed's emergy performance improved, reaching a new renewability of 38%, but it is still not enough to be considered sustainable.     

Safe betting: males help dull females only when they raise high-quality offspring

In evolutionary biology, whether parents should enhance or reduce parental care according to mate ornamentation is a subject of great debate. However, the evolution of female ornaments can shed light on this question. In theory, female ornamentation should be traded off against fecundity and thus cannot be wholly informative to males without a direct indication of fecundity. Hence, direct cues of offspring quality should affect the relationship between male investment and female ornamentation. Under this hypothesis, we manipulated two direct cues of offspring quality (egg size and color) after first egg laying in the blue-footed booby and registered male incubation patterns. In this species, foot color is a dynamic signal of current condition and in females is traded off with egg size. We found that males spent more time incubating when paired with dull females but only in nests with large eggs. Males also spent less time incubating small dull eggs. Results indicate that egg size, a direct cue of reproductive value, affected the relationship between male effort and female ornamentation. Males may be willing to help females that have invested in offspring at the expense of ornamentation, which suggests compensation when females are in low condition. Another possibility is that males relax their effort when paired with highly ornamented and fecund females because they have high parenting abilities. Our findings suggest that the information conveyed by female ornaments may depend on direct cues of fecundity. Results also highlight that parental decisions are complex, modulated by a combination of information sources.