Search results for "ARSENIC"

Reactivity of arsenic compounds on trapping masses and role of the active phase

2019

The aim of the thesis is to study the reactivity of organic arsenic compounds on various recovery masses and to identify the role of the nature of the active phase and the reaction mechanisms involved. The active phase is composed of metals (Ni, Co, Mo, Cu, Zn, Fe, etc.), pure or in a mixture, in the reduced state or in the sulphide state. The selection of the metallic phases will be carried out by molecular modeling "ab initio", and the synthesis by impregnation of metallic salts on mesoporous aluminas). The reactivity of the solids will be studied in a static reactor on simplified model loads, with kinetic monitoring. The advanced characterization of the solids after synthesis and after r…

Arsenic Pollution in the Southwest of Tuscany: Monitoring of Cornia Catchment Basin

2006

The territory of Colline Metallifere, in SW Tuscany, is characterized by the presence of strong arsenic anomalies. Some hypotheses, formulated in the last 20 years, based on geological and mineralogical factors have failed to explain the peculiar distribution of this toxic element in soil, fluvial sediments and ground water. Our research group has been studying for four years the problem of arsenic pollution in this district to investigate the origin and the mechanism of As diffusion in the environment. In particular we started a comparative study based on the extensive sampling of the stream sediments of the main waterways of Colline Metallifere (Pecora, Bruna and Cornia and their tributar…

Spectroscopic studies of molecular arsenic

1995

Arsenic, antimony and bismuth complexation by L-cysteine in water

1984

Synthese, dans l'eau, des complexes L-cysteine: AsL 3 , SbL 3 •H 2 O et BiL 3 .H 2 O L=forme monoanionique de cysteine. Etude IR des structures

Synthesis and characterization of some arsenic, antimony and bismuth complexes of 2-mercaptoaniline

1983

Abstract The complexes of arsenic, antimony and bismuth as well as phenylantimony and phenylbismuth with monoanionic 2-mercaptoaniline are reported. IR spectra are consistent with chelating behaviour of the ligand but only a weak nitrogen to metal bonding interaction is advanced. The mass spectra fragmentation pattern is also presented. It can be interpreted with the loss of successive ligand units and, as a general feature, the abundance of a given ion decreases as the mass of the metal increases. Species with one or two protons less give more intense peaks possibly corresponding to ions containing the dianionic form of the ligand.

Cytotoxic effect of As(III) in Caco-2 cells and evaluation of its human intestinal permeability.

2005

Inorganic arsenic has been classified as a carcinogen for humans (Group I). However, its transit across the human intestinal epithelium has not been characterized. Using Caco-2 cells, the thiol-redox balance and apparent permeability coefficients (P(app)) for As(III) in the apical to basolateral (AP-BL) and basolateral to apical (BL-AP) direction were evaluated. After As(III) exposure, GSH-induced synthesis was observed, increasing the GSH/GSSG ratio by elevating the As(III) concentration. The AP-BL permeabilities decreased as the As(III) concentrations increased, indicating the existence of a mediated transport mechanism. The (BL-AP)/(AP-BL) permeability ratios were higher than unity, sugg…

The removal of sulphate from mine water by precipitation as ettringite and the utilisation of the precipitate as a sorbent for arsenate removal.

2016

Abstract The aim of this research was to investigate sulphate removal from mine water by precipitation as ettringite (Ca6Al2(SO4)3(OH)12·26H2O) and the utilisation of the precipitate as a sorbent for arsenate removal. The mine water sulphate concentration was reduced by 85–90% from the initial 1400 mg/L during ettringite precipitation depending on the treatment method. The precipitation conditions were also simulated with MINEQL + software, and the computational results were compared with the experimental results. The precipitated solids were characterised with X-ray diffraction and a scanning electron microscope. The precipitated solids were tested as sorbents for arsenate removal from the…

Long-term effect of arsenic exposure: Results from an occupational cohort study

2018

Background In 1976 in Manfredonia (Italy), arsenic was released into the atmosphere due to an accident in a petrochemical plant. We aimed to analyze the mortality of workers involved in the factory for the site cleaning activities. Methods The cohort consisted of 1467 workers grouped into contract, fertilizer, and plastic workers. The outcome of interest was mortality for specific causes. Standardized mortality ratios (SMR) and 95% confidence intervals (95%CI) were computed. Results For all workers and all causes of death combined, the SMR was less than 1.0. Mortality ratios were increased for malignant neoplasms of the pleura, bone and melanoma of the skin. Contract workers, the group most…

Assessment of a possible genotoxic environmental risk in sheep bred on grounds with strongly elevated contents of mercury, arsenic and antimony.

1996

A part of Northern Palatinate country (Germany) was formerly influenced by mercury mining. Today, in many cases agricultural and housing areas are placed onto or near to former dump grounds of rubble. In the soil of these areas the concentration of mercury, arsenic and antimony was found ranging from basic natural contents up to strongly elevated levels. In a biomonitoring project, sheep bred on grounds contaminated with mercury (range 1-435 mg Hg/kg dry matter), arsenic (range 17-147 mg As/kg dry matter) and antimony (range 2-15 mg Sb/kg dry matter) were taken as example on the uptake of these elements from the environment and for possible effects of this exposure. Significantly elevated m…

Long-term outcome of older patients with newly diagnosed de novo acute promyelocytic leukemia treated with ATRA plus anthracycline-based therapy

2018

Treatment outcome in older patients with acute promyelocytic leukemia (APL) is lower compared with younger patients, mainly because of a higher induction death rate and postremission non-relapse mortality (NRM). This prompted us to design a risk-and age-adapted protocol (Programa Espanol de Tratamientos en Hematologia (PETHEMA)/HOVON LPA2005), with dose reduction of consolidation chemotherapy. Patients aged >= 60 years reported to the PETHEMA registry and were treated with all-trans retinoic acid (ATRA) plus anthracycline-based regimens according to three consecutive PETHEMA trials that were included. We compared the long-term outcomes of the LPA2005 trial with the preceding PETHEMA tria…