Oxidative damage to Pseudomonas aeruginosa ATCC 27833 and Staphylococcus aureus ATCC 24213 induced by CuO-NPs

Environmental Science and Pollution Research - The cytotoxicity of nanoparticles (NPs) and their properties are important issues in nanotechnology research. Particularly, NPs affect the metabolism...     

Tributyltin chloride disrupts aortic vascular reactivity and increases reactive oxygen species production in female rats

Environmental Science and Pollution Research - Organotin compounds, such as tributyltin (TBT), are environment contaminants that induce bioaccumulation and have potential toxic effects on marine...     

Modeling road building,deforestation and carbon emissions due deforestation in the Ecuadorian Amazon: the potential impact of oil frontier growth

In the Ecuadorian Amazon roads play the major role in transforming land cover. Since the beginning of the oil development in this region, oil exploration and road building have been linked. The objectives of this paper are twofold: First, to present a scenario of future deforestation as result of expanding the oil frontier in the Ecuadorian Amazon until the year 2030. Second, to produce an analysis of possible carbon emission scenarios as results of the deforestation produced. This paper tries to shed light into how the development of new oil concessions impact land associated environmental services. The paper uses spatial explicit simulations, that are based on parameters built using past land transitions from areas that experimented oil development, and that explain possible outcomes in the year 2030 using current and predicted road network. Simulations indicate that under current transition probabilities and a conservative scenario road construction, more than 2 million hectares will be affected, which is 35% of the area covered by concessions, which would release 51 to 148 MT of carbon to the atmosphere. This paper illustrates the strong links between road building and deforestation, where even small amount of road construction can have large effects on land cover.     

Presence, distribution, and origins of polycyclic aromatic hydrocarbons (PAHs) in sediments from Bahía Blanca estuary, Argentina

This paper is the first comprehensive survey of polycyclic aromatic hydrocarbons (PAHs) in coastal sediments in Bahia Blanca, Argentina, and provides useful information on their levels of concentration, composition, and sources of these pollutants. The total concentrations of PAHs ranged from 15 to 10,260 ng g^???1. The highest contents (mean 3,315 ng g^???1) of total PAHs in marine sediments were found in the inner channels of the estuary, while the lower ones (204 ng g^???1) belong to samples collected far away from contamination sources. The global average recorded in this study (1,500 ng g^???1) indicates that the studied area lies within the referenced category of industrialized coastal zones under chronic pollution. The diagenetic PAH contribution was found to be negligible at all sampled locations; however, the calculation of molecular ratios determined an overimposition of pyrolitic PAHs over the petrogenic input. Further, the use of principal components analysis (PCA) clearly separated ring group compounds and enabled the determination of pyrolitic/combustion PAHs dominancy.     

Changes in air pollution during COVID-19 lockdown in Spain: A multi-city study

The COVID-19 pandemic has escalated into one of the largest crises of the 21st Century. The new SARS-CoV-2 coronavirus, responsible for COVID-19, has spread rapidly all around the world. The Spanish Government was forced to declare a nationwide lockdown in view of the rapidly spreading virus and high mortality rate in the nation. This study investigated the impact of short-term lockdown during the period from March 15th to April 12th 2020 on the atmospheric levels of CO, SO₂, PM₁₀, O₃, and NO₂ over 11 representative Spanish cities. The possible influence of several meteorological factors (temperature, precipitation, wind, sunlight hours, minimum and maximum pressure) on the pollutants' levels were also considered. The results obtained show that the 4-week lockdown had significant impact on reducing the atmospheric levels of NO₂ in all cities except for the small city of Santander as well as CO, SO₂, and PM₁₀ in some cities, but resulted in increase of O₃ level.     

Organochlorine concentrations in franciscana dolphins, Pontoporia blainvillei, from Brazilian waters

Blubber samples were collected from ten franciscana dolphins either incidentally captured in fishing operations or stranded on São Paulo (SP) and Paraná (PR) states littoral, Southeastern and Southern Brazilian coast, respectively. Determination of PCB, DDT and HCB concentrations were performed by capillary gas chromatograph coupled to electron capture detector (ECD). ΣDDT, ΣPCB and HCB concentrations ranged from 264 ng g⁻¹ to 5811 ng g⁻¹ lipid, from 909 ng g⁻¹ to 5849 ng g⁻¹ lipid and from 10 ng g⁻¹ to 61 ng g⁻¹ lipid, respectively. Regarding DDTs, the distribution of the mean percentages decreased in the following order: p,p′-DDE > p,p′-DDD > p,p′-DDT. The ΣDDT/ΣPCB ratio varied between 0.27 and 0.42 in Northern and Central SP coast, while in Southern SP and PR coast the values were 1.6 and 1.9, respectively. Dissimilarities in ΣDDT/ΣPCB ratios point to different sources of organochlorine compounds to franciscana dolphins in the study area. Considering the endocrine disruptive action of organochlorine compounds, the concentrations found in franciscana dolphins from Brazilian waters may represent an additional obstacle to the conservation of this endangered cetacean species.     

Glycolysis of flexible polyurethane wastes using stannous octoate as the catalyst

Flexible polyurethane foam wastes can be advantageously treated by two-phase glycolysis to recover the polyols with an improved quality compared to single-phase processes. This reaction has been traditionally catalyzed by alkanolamines, titanium compounds, or acetates. Recently, the employment of new catalysts based on potassium and calcium octoates has opened up a new way to catalyze the glycolysis of polyurethanes. In this work, the use of stannous octoate, which has never before been applied in the glycolysis reactions of polyurethanes, is proposed. The catalytic activity of stannous octoate in such a process was studied. The decomposition rate and the purity of polyol obtained were greater than those obtained using other catalysts previously employed for this application.     

Understanding slums: analysis of the metabolic pattern of the Vidigal favela in Rio de Janeiro,Brazil

This paper illustrates an innovative approach to characterize the metabolic pattern of informal urban settlements or slums with the aim to better understand the factors that affect the material standard of living of slum residents, the dynamics of slum development and the interaction of the slum with its wider socioeconomic context. The proposed system of accounting, multi-scale integrated analysis of societal and ecosystem metabolism (MuSIASEM), integrates socioeconomic and spatial data and studies energy and monetary flows in relation to the pattern of human activities and land uses. The theoretical basis of the approach is illustrated with data from Vidigal favela in Rio de Janeiro, Brazil. In particular, we show how to construct taxonomies of accounting categories to characterize: (1) the set of activities carried out by the slum dwellers, to which to link assessments of flow rates per hour; (2) the set of land uses or spatial elements making up the slum, to which to link assessments of flow densities per hectare. The analysis of the interaction of Vidigal with its wider socioeconomic context focuses on monetary flows and transport (job commuting).     

Detection and quantitative analysis of 21 veterinary drugs in river water using high-pressure liquid chromatography coupled to tandem mass spectrometry

Introduction

The use of veterinary drugs in food production focuses on the control and improvement of animal health. The disadvantage of this practice is that pharmaceuticals and their metabolites are released into the environment, finding their way to natural water systems and becoming a potential risk to non-target organism.

Methods

This paper reports the development and validation of a quantitative method, based on high-performance liquid chromatography coupled to tandem mass spectrometry, for the simultaneous analysis of 21 veterinary drugs, antimicrobials, corticosteroids, coccidiostats and antifungal agents, in surface water.

Results

The precision of the method was established by calculating the mean recoveries, which were in the range of 94?C101%. The developed method was employed to conduct the first monitoring study on the presence of veterinary drugs in the Galicia region, Northwest of Spain and was applied to 235 surface water samples. Eleven veterinary drugs were detected at concentrations from below the limit of quantification to 2,978.6?ng?L^?1. Limits of detection and quantification were in the range of 6.2 (betamethasone, cortisone, decoquinate, dexamethasone, maduramycin, monensin, narasin, salinomycin, sulfachloropyridazine, sulfamethoxypyridazine and trimethoprim) to 12.5?ng?L^?1 (for the rest of the selected drugs) and 12.5 (betamethasone, cortisone, decoquinate, dexamethasone, maduramycin, monensin, narasin, salinomycin, sulfachloropyridazine, sulfamethoxypyridazine and trimethoprim) to 25.0?ng?L^?1 (for the remaining pharmaceuticals), respectively.

Conclusion

Sulfonamides were the group most frequently found, which are widely used in veterinary medicine.