A. Contu
University of Cagliari
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Featured researches published by A. Contu.
Environmental Monitoring and Assessment | 2010
Marco Schintu; Barbara Marras; L Durante; P Meloni; A. Contu
The levels of Cd, Cu, Pb, and Zn were determined in the commonest species of green, red, and brown algae collected from five coastal sites in south-western Sardinia (Italy), an area with a long history of mining and smelting. The usefulness of employing Enteromorpha sp. and Padina pavonica (L.) Thivy to monitor metal pollution was evaluated, while diffusive gradients in thin films (DGT) devices were used to measure dissolved metals in seawater. Levels of Cd and Pb were high enough to be of environmental concern in the whole study area. A significant relationship was found between the content of Pb in P. pavonica and DGT-labile Pb in seawater, suggesting that gross elemental concentrations of nonessential metals such as Pb in algal tissues are apparently controlled by the abundance of dissolved metal species in the ambient seawater. The results pointed out the usefulness of using both DGT and algal methods for a better understanding of trace metal availability in coastal waters.
Water Air and Soil Pollution | 1988
Alberto Loizzo; Nicola Sechi; Laura Volterra; A. Contu
This paper summarizes biological, microbiological, physico-chemical and toxicological analyses carried out during a bloom of Oscillatoria rubescens D.C. in two Sardinian lakes that began in January and lasted 7 mo. The algal species was found to be biotoxins producer. The toxicity was confirmed through laboratory tests. Acute LD50 in mice was about 120 mg kg−1 body weight i.p. and at the necroscopic examination animals showed ochraccous dashes on the liver. When subacute p.o. toxicity tests were performed, in liver cells swollen, fragmented or twinned nuclei appeared in a dose related manner. During the bloom the eutrophic lakes exhibited a reduced number of microbial fecal indicators and a rich population of environmental bacterial flora.
Water Air and Soil Pollution | 1991
Marco Schintu; Akira Kudo; G. Sarritzu; A. Contu
This study was prompted by concern about the possible heavy metal contamination of the Flumendosa lake, a drinking water reservoir located downstream from the Funtana Raminosa mining area, in Sardinia (Italy). Extremely high concentrations of Pb, Cd and Cu were found in the Rio Sarraxinus, a small tributary of the Flumendosa river which drains the mining area. Sediment cores from the reservoir showed high contents of all three metals. In order to investigate the partitioning of the metals in the main components of the sediments, a scheme of sequential extractions was used. The results indicate an important role of the organic matter in binding Pb and Cd in the sediment of the reservoir. Percentages of non-residual Pb and Cd bound to the organic matter were significantly higher in the reservoir sediments than in those from the tributaries, while the highest percentages of Cu were associated with the organic matter both in lake and in river sediments. However most of the Cd and Pb both in lake and fluvial sediments were bound to the carbonates and to Fe-Mn oxides, which are exposed to chemical changes and then susceptible to metal remobilization in the water.
Ecotoxicology and Environmental Safety | 1987
Marco Schintu; Tiit Kauri; A. Contu; Akira Kudo
A simple method to isolate both organic and inorganic mercury in natural waters is described. The mercuric compounds were quantitatively extracted with dithizone from six different kinds of water spiked at nanogram levels with radioactive mercuric chloride and methylmercuric chloride. After the separation from the inorganic mercury with sodium nitrite, methyl mercury was transferred to aqueous medium with sodium thiosulfate. The method provides a high recovery of organic as well as inorganic mercury to an aqueous medium, prior to their determination by gold-trap cold vapor atomic absorption spectrophotometry. This method is easy, rapid, and inexpensive. Furthermore, the limited number of analytical steps should reduce loss and contamination.
International Journal of Environmental Research and Public Health | 2012
Piergiorgio Bolasco; A. Contu; P Meloni; Dorio Vacca; Andrea Galfré
Methods: The present report attempts to illustrate the positive impact on the microbiological quality of dialysis patients over a 15-year period through the progressive implementation of state-of-the-art technological strategies and the optimization of microbiological surveillance procedures in five dialysis units in Sardinia. Results: Following on better microbiological, quality controls of dialysis water and improvement of procedures and equipment, a drastic improvement of microbiological water quality was observed in a total of 945 samples. The main aim was to introduce the use of microbiological culture methods as recommended by the most important guidelines. The microbiological results obtained have led to a progressive refining of controls and introduction of new materials and equipment, including two-stage osmosis and piping distribution rings featuring a greater capacity to prevent biofilm adhesion. The actions undertaken have resulted in unexpected quality improvements. Conclusions: Dialysis water should be viewed by the nephrologist as a medicinal product exerting a demonstrable positive impact on microinflammation in dialysis patients. A synergic effort between nephrologists and microbiologists undoubtedly constitutes the most effective means of preventing dialysis infections.
Blood Purification | 2012
Piergiorgio Bolasco; A. Contu; P Meloni; Dorio Vacca; Stefano Murtas
Aim: This report attempts to illustrate the positive impact on the quality of dialysis water produced over a 16-year period through the progressive optimization of technological procedures. Methods: Fundamental steps included the following: elimination of polyvinyl chloride (PVC), periodical controls, introduction of stainless steel and/or polyethylene polymer and substitution of single-pass reverse osmosis (SRO) with double-pass reverse osmosis (DRO). Daily overnight automatic thermal disinfection of distribution piping rings represented the final step. Results: A dramatic improvement was observed in 645 water samples obtained from distribution piping. The measures applied resulted in a significant improvement of water quality, featuring levels of colony-forming units per milliliter ranging from 247.4 ± 393.7 in the presence of PVC and SRO to 14.1 ± 28.0 with stainless steel and DRO and 2.8 ± 3.2 with cross-linked polyethylene thermoplastic polymer and DRO (p < 0.01). Conclusions: Dialysis water should be viewed by nephrologists as a medicinal product, and every effort should be made to ensure a high-quality liquid.
Bulletin of Environmental Contamination and Toxicology | 1990
A. Contu; Mauro Bordigoni; Graziano Sarritzu; Guido Premazzi; Mariano Pudda; Marco Schintu
There has been increasing uneasiness with the health authorities recently about the almost ubiquitous presence of organohalogenated compounds in drinking waters. The scientific interest in trihalomethanes (THMs) has increased since their carcinogenic properties were ascertained. For this reason several countries have set upper limits and guidelines for the total amount of THMs allowed in drinking waters which vary from country to country. Aiming at a better understanding of the maximum acceptable concentrations of THMs in drinking waters and considering the wide range of reported values in different countries, it has been considered useful to carry out a study on the presence of THMs in some Sardinian waters. This paper is an attempt at evaluating the THM concentration in the water distributed in the different villages; the final remarks will serve as premises for future studies both on the factors inducing such formation and on problems of risk for human health.
Ecotoxicology and Environmental Safety | 2000
Marco Schintu; P Meloni; A. Contu
Chemosphere | 2005
Marco Schintu; A. Cogoni; L Durante; C. Cantaluppi; A. Contu
Diabetes Care | 2000
Anna Casu; Marcello Carlini; A. Contu; Gian Franco Bottazzo; Marco Songini