Screening risk assessment tools for assessing the environmental impact in an abandoned pyritic mine in Spain

This paper describes a new methodology for assessing site-specific environmental impact of contaminants. The proposed method integrates traditional risk assessment approaches with real and variable environmental characteristics at a local scale. Environmental impact on selected receptors was classified for each environmental compartment into 5 categories derived from the whole (chronic and acute) risk assessment using 8 risk levels. Risk levels were established according to three hazard quotients (HQs) which represented the ratio of exposure to acute and chronic toxicity values. This tool allowed integrating in only one impact category all the elements involved in the standard risk assessment.The methodology was applied to an abandoned metal mine in Spain, where high levels of As, Cd, Zn and Cu were detected. Risk affecting potential receptors such as aquatic and soil organisms and terrestrial vertebrates were assessed. Whole results showed that impact to the ecosystem is likely high and further investigation or remedial actions are necessary. Some proposals to refine the risk assessment for a more realistic diagnostic are included.     

Evaluation of chemical components of debittered olives undergone preservation and polyphenol oxidation

Olives can reduce their bitterness by oleuropein oxidation via an enzymatic reaction. In this study, olives of the Manzanilla and Hojiblanca varieties preserved in acidified brine were submitted to oxidation tests under overpressure of oxygen (0.3 bars) for 3 days. It was found that the oxidation of fruit preserved for more than 3–4 months showed a reduction in the concentration of oleuropein, but with great variability (28–100%). By contrast, when olives were preserved for only one month, the oxidation treatment was able to decrease more than 90% of the content of oleuropein in the fruit. These oxidised olives were stored again in the acidified medium for 6 months and no spoilage or organoleptic problems were detected. Oxidation gave rise to darker olives (L* parameter diminished from 40 to 34). Moreover, the oxidised fruit was enriched with free phenols such as hydroxytyrosol and tyrosol as a consequence of the acid hydrolysis of phenolic glucosides during the preservation step.