Search results for "contamination"
showing 10 items of 916 documents
Effects of heavy metals on earthworms along contamination gradients in organic rich soils.
2003
Earthworm communities and metal (bio)availability to earthworms along contamination gradients was studied in order to support chemical analyses in risk assessment of metal contaminated soils. Earthworms were sampled in three metal contaminated areas with different habitat and soil properties in Finland. Earthworm and soil samples were collected at three distances (1, 2, and 4 km) from the emission sources. Earthworms were identified as to species and analyzed for heavy metals. Total soil metal concentrations were analyzed using an ultrasound-assisted extraction method and bioavailable metal fraction was estimated by acetic acid extraction. In two of the three areas studied, heavy metal conc…
ASSESSING MERCURY POLLUTION USING BLACK STORK EGGSHELLS
2021
Female birds whose bodies contain environmental contaminants produce eggs with shells that are likewise contaminated, making bird eggshells appropriate indicators for monitoring environmental toxins. Common contaminants include organic mercury compounds, especially methylmercury, which are known to bioaccumulate and biomagnify in the food chain. Black storks (Ciconia nigra) predominantly consume fish and are thus at risk for high mercury intake. In this study, we used eggshells of black storks as a proxy to reconstruct the concentration levels and distribution of mercury, a well-known toxic element, in various parts of Latvia. Preliminary analyses have shown that deposition levels of mercur…
Incidence of heavy metals in the application of inorganic fertilizers to rice farming soils (Valencia, Spain)
1996
The presence of Cd, Co, Cu, Ni, Pb, Zn, Fe and Mn in different inorganic fertilizers (urea, calcium superphosphate, iron sulphate and copper sulphate) are evaluated and the contribution of these metals to the soils in this way is estimated. The studied zone corresponds to rice farming and is at the north of Albufera Natural Park (Valencia, Spain). The results obtained show that Superphosphate is the fertilizer that contains the highest levels of Cd, Co, Cu and Zn as impurities. Copper sulphate and iron sulphate have the most significant contents of Pb, and are the only fertilizers in which Ni is detected. The most significant additions of impurities that the soil received by agricultural pr…
The importance of dead seagrass (Posidonia oceanica)matte as a biogeochemical sink
2022
We assessed the potential of dead seagrass Posidonia oceanica matte to act as a biogeochemical sink and provide a coherent archive of environmental change in a degraded area of the Mediterranean Sea (Augusta Bay, Italy). Change in sediment properties (dry bulk density, grain size), concentration of elements (Corg, Cinorg, N, Hg) and stable isotope ratios (δ13C, δ 15N) with sediment depth were measured in dead P. oceanica matte and unvegetated (bare) sediments in the polluted area, and an adjacent P. oceanica meadow. Principal Component Analysis (PCA) revealed a clear clustering by habitat, which explained 72% of variability in our samples and was driven mainly by the accumulation of N and H…
Efficacy of four cleaning solutions for the decontamination of selected cytotoxic drugs on the different surfaces of an automated compounding system
2018
The automated aseptic preparation of ready-to-administer antineoplastic drug solutions with robotic systems reduces the risk of occupational exposure. However, the surfaces in the preparation area of the robot are to be cleaned by wiping with an appropriate cleaning solution. The aim of the study was to evaluate the cleaning efficacy of four cleaning solutions on four surface materials installed in the APOTECAchemo robot. Predefined amounts of cisplatin (Cis), 5-fluorouracil (5-FU), and cyclophosphamide (CP) were intentionally spread on test plates made of stainless steel, aluminium, polyoxymethylene, and polycarbonate just as installed in the robotic system APOTECAchemo. After drying, the …
Reticular Metal-Organic Frameworks for sustainable applications
2023
La presente tesis doctoral se ha realizado mediante compendio de publicaciones en cumplimiento con las normativas establecidas por la Universidad de Valencia, según lo dispuesto en el reglamento ACGUV 266/2011 referente al depósito, evaluación y defensa de tesis doctorales, con la última actualización correspondiente al 31 de Octubre de 2017. El trabajo se encuentra estructurado en tres capitulos principales, seguidos de un capítulo final que engloba las conclusiones obtenidas a partir de los resultados de la investigación, así como los planes y perspectivas para trabajos futuros. El capitulo 1 proporciona un contexto general sobre los materiales abordados en esta tesis: Metal-Organ…
FORENSIC MICROBIOLOGY: A CASE SERIES ANALYSIS
2019
The importance of microbial colonization of human organs in a living body has long been assessed. What still remains unclear are the microbial changes occurring after death, thus leading to the advent of a relatively novel field of research called “Postmortem microbiology”. It is applied to several forensic fields such as post-mortem interval assessment and cause of death determination. In this contest, a major limit is thus represented by the correct interpretation of the microbial data and by the actual lack of standard procedures. Here we propose a standard operative protocol in order to avoid false positives given by contamination (the main problem), post-mortem translocation and agonal…
Microwave-assisted extraction of OCPs, PCBs and PAHs concentrated by semi-permeable membrane devices (SPMDs)
2005
Abstract Microwave-assisted extraction (MAE) has been evaluated as an alternative to dialysis for extraction of some water-borne hydrophobic contaminants sampled by semi-permeable membrane devices (SPMDs). Seven organochlorine pesticides (OCPs), 11 polychlorinated biphenyls (PCBs) and 13 polycyclic aromatic hydrocarbons (PAHs) were accumulated in SPMDs at nanogram levels and extracted with three 3-min irradiation cycles with 33 mL of a solvent mixture hexane–water (10:1,v/v) in each cycle. The developed MAE method gave for all analytes investigated statistically comparable extraction yields with those found by dialysis carried out with a total volume of 250 mL hexane for 48 h at room temper…
The abundance of Au, Pt, Pd, and the mode of heavy metal fixation in highly polluted sediments from the Rhine River near Mainz, West Germany
1984
The Au, Pt and Pd contents of the sediments of Ginsheimer‐Altrhine River, a channel of the Rhine river which drains one of the most industrialized regions of western Europe, have been determined by flameless atomic absorption spectrophotometry. The abundances of these noble metals range from 96–460 ppb Au; 734 ppb‐31 ppm Pt and 32 ppb‐4 ppm Pd. The extremely high concentrations, particulary those of Pt and Pd, are attributed to their use in industry and are due to the formation and concentration of metal‐organic complexes, mainly at the interface between an extremely reducing and an oxidizing aquatic environment. Differential thermal analyses of the polluted sediments in comparison to the p…
Organic chlorine compounds in lake sediments. II Organically bound chlorine
1990
Abstract Organically bound chlorine together with inorganic chloride was measured from dated bottom sediment layers of 18 lakes in Central Finland and compared to organic matter contents. Pulp mills were found to be the source of significant increase of the accumulation of all of these materials in the 20th century.