In this work we present maps of estimates of background values of some harmful metals (As, Cd, Co, Cr, Cu, Hg, Mn, Ni, Pb, V, and Zn) in the soils of Santiago Island, Cape Verde, analyse their relationships with the geological cartography, and assess their environmental risks. The geochemical survey (soil sampling at a spatial resolution of 3 sites per 10 km2, sample preparation, geochemical analysis, data treatment, and mapping) was conducted following the guidelines proposed by the International Projects IGCP 259 and IGCP 360. The concentration of the selected elements was determined in the fraction <2 mm. Each sample was digested with aqua regia and analysed by ICP-MS. The Estimated Background Value spatial distributions of the studied metals are found to be strongly linked to the geological cartography. These links are identified by a direct comparison of the geochemical maps with the geological cartography, and confirmed by either simple statistics and a Principal Component Analysis. The metals with higher loadings in the first Principal Component, Ni, Cr, Co, Cu, and V, clearly show the influence of a lithology rich in siderophile elements, typical of basic rocks and of its related minerals. The elements with higher loadings in the second Principal Component, Mn, Zn, Pb, As, Hg, and Cd, are chalcophile elements, except for Mn, but an anthropogenic contamination for these elements cannot be discarded. We propose an index to numerically access the environmental risk of one element, which we denominate by Environmental Risk Index, and a Multi-element Index which is simply the average taken over all elements. The occurrence of values greater than 1 in the maps of the Environmental Risk Index shows where the content of the respective element is above the permissible levels according to the available legislation for agricultural and residential purposes. The same applies to the multi-element risk index maps. High values of these risk indices are found, both for agricultural and residential purposes, for Co, Cr, Ni, Cu, and V. These metals are precisely those with higher loadings in PC1, which are demonstrated to be of natural origin in Santiago. This behaviour is also shown in the Multi-element Environmental Risk maps computed with these five metals. The high natural concentration levels of heavy metals at some areas of Santiago should be of concern not only to scientists but also to policymakers. To further evaluate the environmental risks associated with the presence of these metals, their bioavailability should be assessed in future works.

The Vale de Abrutiga uranium deposit, located in Central Portugal near the Aguieira dam reservoir, was surface mined. Low-grade ore and waste rock were deposited on permeable ground, close to the mine, and were not revegetated. A lake has formed in the open pit. Surface waters draining the mine site are acidic, have high conductivity, and high concentrations of U, SO42-, Zn, Fe, Mn, Ra, Cu, Th, and Pb. The groundwater and the water from the reservoir cannot be used for human consumption or irrigation. The sampled waters show higher contaminant concentrations in winter than in summer. Stream sediments have high geoaccumulation indices for U, Fe, Ag, Zn, Cr, Co, and Pb. In general, sediments bordering the dam reservoir have higher metal contents in winter than in summer.

Effects of porcine bile extracts added at three different dietary concentrations 0, 10 and 20 g kg)1 were studied on astaxanthin serum concentration in rainbow trout (mean weight 200 ± 7 g). Astaxanthin from micro-algae Haematococcus pluvialis and synthetic astaxanthin (CAROPHYLL pink) were incorporated in diets of rainbow trout at a rate of 100 mg astaxanthin kg)1 of feed. Fish were hand fed twice a day. After 5 days of feeding there was a significant effect of the pigment source on the ratio (total blood astaxanthin per unit body weight to cumulative astaxanthin intake per unit body weight). Trout receiving synthetic astaxanthin showed a significantly (P < 0.05) higher ratio than trout fed algal astaxanthin. Increasing dietary bile extract did not lead to produce any effect on this ratio. The power of the statistical analysis is discussed. Therefore, the interaction (pigment source · dietary bile concentration) showed no more effect.

Although Haematococcus pluvialis is one of the most importantnatural sources of the carotenoid astaxanthin as a pigmentor for theaquaculture industry, the thick sporopollenin cell wall in the cysts hindersastaxanthin extraction and its subsequent bio-availability to fish. A rangeof physical and chemical processes were tested to promote the disruptionof the encysted cells. The efficacy of these processes was evaluated interms of astaxanthin recovery, which was assessed by determining theextent of leaching of astaxanthin into an organic solvent. The processestested were: autoclave 30 min, 121 °C, 1 atm; HCl 0.1 M, 15min and 30 min; NaOH 0.1 M, 15 min and 30 min; enzymatictreatment with a mixture of 0.1% protease K and 0.5% driselase in aphosphate buffer, pH 5.8, 30 °C, for one hour; spray drying, inlet180 °C, outlet 115 °C; and mechanical disruption, with acell homogeniser developed for this purpose. The mechanical(homogenisation) and autoclave treatments were the most effective in termsof extraction and availability.

Biological dosimetry (biodosimetry) is based on the investigation of radiation-induced biological effects (biomarkers), mainly dicentric chromosomes, in order to correlate them with radiation dose. To interpret the dicentric score in terms of absorbed dose, a calibration curve is needed. Each curve should be constructed with respect to basic physical parameters, such as the type of ionizing radiation characterized by low or high linear energy transfer (LET) and dose rate. This study was designed to obtain dose calibration curves by scoring of dicentric chromosomes in peripheral blood lymphocytes irradiated in vitro with a 6 MV electron linear accelerator (Mevatron M, Siemens, USA). Two software programs, CABAS (Chromosomal Aberration Calculation Software) and Dose Estimate, were used to generate the curve. The two software programs are discussed; the results obtained were compared with each other and with other published low LET radiation curves. Both software programs resulted in identical linear and quadratic terms for the curve presented here, which was in good agreement with published curves for similar radiation quality and dose rates.