Presence Of Inorganic Contaminants Research Articles

As, Cd, Cr, Pb and Hg in seafood species used for sashimi and evaluation of dietary exposure

The presence of inorganic contaminants As, Cd, Cr, Hg and Pb was evaluated in 116 samples of muscles of seafood used for sashimi from Japanese restaurants in Campinas, SP, Brazil. Tuna (Thunnus thynnus), salmon (Salmo salar), mullet (Mugil platanus) and octopus (Octopus vulgaris) were the most common seafood species in these restaurants. Samples were digested in a microwave assisted system and the contaminants were determined by inductively coupled plasma (ICP OES). The percentage of samples above the maximum limit permitted by MERCOSUL and European regulations were: As (90% tuna, 48% salmon, 31% mullet and 100% octopus); Cd (61% octopus); Hg (7% tuna); Pb (6% mullet). Octopus and tuna were the sashimi that most contributed to arsenic and mercury intake, respectively.

New approach for evaluating the public health risk of living near a polluted river.

Chemical, physical and microbial analyses were conducted in the Sarno River basin to obtain a comprehensive description of the overall quality of the water bodies. The collection period lasted 12 months, between 2005 and 2006, with high frequency of sampling and analysis. More than 6,000 analytical determinations were performed on samples collected at six sampling points along the Sarno River and two points each on tributaries Solofrana and Cavaiola. The results indicated the presence of inorganic contaminants, which, in most cases, were below the Italian State water quality thresholds. The organic contamination showed an increasing trend, with respect to previous determinations, thus demonstrating the major contribution of untreated urban wastewater to the overall pollution of the river. Moreover, this study was designed to explore the correlation between the presence of microbial indicators of fecal contamination in Sarno River and their presumable presence in the aerosol surrounding the river, thus pointing to the possible environmental hazard associated with the presence of pathogens in the air.

Residual aluminum oxide on the surface of titanium implants has no effect on osseointegration

The cleanliness of titanium dental implants surfaces is considered to be an important requirement for achieving osseointegration, and it has been hypothesized that the presence of inorganic contaminants could lead to lack of clinical success. Aluminum ions are suspected to impair bone formation by a possible competitive action to calcium. The objective of the present study was to describe the effects of residual aluminum oxide particles on the implant surface on the integration of titanium dental implants as compared to decontaminated implants in a rabbit experimental model. Threaded screw-shaped machined grade 3 c.p. titanium dental implants, produced with high-precision equipment, were used in this study. The implants were sandblasted with 100–120 μm Al 2O 3 particles at a 5 atm pressure for 1 min, then 24 implants (control implants) underwent ASTM F 86-68 decontamination process in an ultrasonic bath. The other 24 implants (test implants) were washed in saline solution for 15 min. Both test and control implants were air-dried and sterilized at 120°C for 30 min. After sterilization the implants were inserted into the tibiae (two test and two control implants in each rabbit). Twelve New Zealand white mature male rabbits were used in this study. The protocol of the study was approved by the Ethical Committee of our University. No complications or deaths occurred in the postoperative period. All animals were euthanized, with an overdose of intravenous pentobarbital, after 4 weeks. A total of 48 implants were retrieved. The images were analyzed for quantitation of percentage of surface covered by inorganic particles, bone–implant contact, multinucleated cells or osteoclasts in contact with the implant surface and multinucleated cells or osteoclasts found 3 mm from the implant surface. The differences in the percentages between the two groups have been evaluated with the analysis of variance. The implant surface covered by inorganic particles on test implants was significantly higher than that of control implants ( p=0.0000). No statistically significant differences were found in the bone–implant contact percentages of test and control implants ( p=0.377). No statistically significant differences were found in the number of multinucleated cells and osteoclasts in contact with the implant surface ( p=0.304), and at a distance of 3 mm from the implant surface ( p=0.362). In conclusion, our histological results do not provide evidence to support the hypothesis that residual aluminum oxide particles on the implant surface could affect the osseointegration of titanium dental implants.

A Geochemical and Biological Basis for Marine Sediment Quality Guidelines

This document describes a basis for the establishment of marine sediment quality guidelines for regulatory applications. It outlines a geochemical basis for identifying potential anomalies in the presence of inorganic contaminants in marine sediments and a biological or ecotoxicological basis for determining concentrations unlikely to result in adverse biological effects. These approaches are discussed in an exploratory fashion. It is intended that both approaches could be combined in a manner that takes account of sedimentary nature and composition as a conceptual and practical approach to the establishment of guidelines for regulatory applications associated with the protection of the marine environment.

Silica‐conalbumin conjugate as an inexpensive alternative for metalloprotein affinity metal chromatography

Abstract A newly developed method of chromatography based on the affinity of metal ions for the apometalloprotein conalbumin (ovotransferrin, OT) has the potential to decontaminate and selectively recover metal ions from wastewater [1, 2]. The presence of inorganic contaminants in surface water is perhaps one of the most important environmental issues of our time. Thus, efforts to solve this problem by applying our recent understanding of metal‐protein interactions has lead us to the search for different apometalloproteins that could be affixed to inert supports to act as affinity media for a variety of heavy metal ions. The successful immobilization of conalbumin onto sepharose has served as an entry into this chemistry; however, the ability to apply this methodology away from the laboratory environment is highly dependent on the cost and robustness of the support employed, as well as the cost of the reagents and methods utilized to achieve a functional metal affinity column. Results in the direction of reducing the cost of the support and the methodology involved are presented here.

Corrosion of Steel by Chlorinated Solvents and its Inhibition I. Factors affecting the decomposition of CCl4and its action on mild steel

AbstractThe corrosion of mild steel by chlorinated solvents has been investigated. The evidence of acid formation as a result of decomposition of CCl4 and of the corrosive action of the degraded solvent on mild steel has been reported. In the presence of water in CCl4 a number of metals produced acid, both when exposed in the liquid or in the vapour, more in the latter case. In general, the catalytic activity of different metals in decomposing CCl4 was in the following decreasing order: mild steel, aluminium, copper, zinc. Nickel, stainless steel and brass did not decompose the solvent. Higher temperatures (> 10°C), longer test periods, a higher water content, the presence of inorganic contaminants and exposure to UV radiation caused more decomposition of CCl4 and greater attack on mild steel. Boiling solvent (containing H2O) or the vapour therefrom prodūced greater corrosion. Hot condensate either flowing past the metal specimens or wetting and drying them alternately produced maximum corrosion.