Domingo Román

Copper, copper mine tailings and their effect on marine algae in Northern Chile

Results are presented of a long-term research programme on the effect of copper contamination on biota in Chilean coastal waters. In spite of the magnitude of the copper mining tailings that affected Caleta Palito and surroundings in northern Chile, the effects on the intertidal assemblages remain restricted to a small geographic area. Even within the affected area, the effects are not homogeneous and there is evidence of active recovery in biological diversity in recent few years. Experimental evidence suggests that the current low algal diversity and abundance is strongly influenced by herbivory, although chronic effects of the discharges cannot be ruled out. Cellular changes in Enteromorpha compressa from the impacted area were characterised by abnormal granules in the cytoplasm, though these granules did not contain detectable levels of copper or other heavy metals.

Copper, Copper Mining Effluents and Grazing as Potential Determinants of Algal Abundance and Diversity in Northern Chile

We experimentally tested threealternative hypotheses to explain the low algaldiversity and abundance in an intertidal zonereceiving the effluents of the copper mine El Salvadorin northern Chile. Our results demonstrated thatalgae were able to grow at the levels of dissolvedcopper detected in coastal waters of the area. Duringthe assays, growth and regeneration in several red,green and brown adult algae and juvenile Lessonia nigrescens were normal at copper levels of150 μg L-1 or, in some cases, higher. Wealso found that the coastal sea water mixed with theeffluent was not lethal to algae, although in somecases minor effects on growth were detected. Theseresults indicate that todays low algal diversity andabundance can not be explained by the current copperlevels in the area nor by the effect of the effluent.Exclusion of grazers, however, resulted in a fastcolonization by various algal species. This, togetherwith atypically high grazer density at the areas underthe influence of the effluent, strongly suggests thatherbivory, a factor not directly related to the miningoperation, is likely to be responsible for the lowalgal diversity and abundance in the studied locality.

An approach to the arsenic status in cardiovascular tissues of patients with coronary heart disease

Among non-cancer effects of arsenic, cardiovascular diseases have been well documented; however, few are known about the arsenic fate in cardiovascular tissues. We studied the analytic bioinorganic arsenic behaviour in cardiovascular tissues from an arsenic exposure coronary heart disease patient group from Antofagasta-Chile against a small unexposed arsenic coronary heart patient group. Total arsenic concentrations were measured in pieces of cardiovascular tissues of the arsenic-exposed and unexposed coronary heart patient groups by hydride generation atomic absorption spectrometry (HG-AAS); speciation analysis was made by high performance liquid chromatography-inductively coupled plasma-mass spectrometry (HPLC-ICP-MS). Pieces of auricle (AU), mammary artery (MAM), saphenous vein (SAP) and fat residuals (FAT) were considered in this study. The arsenic concentrations in AU and MAM tissues were significantly different between both groups of patients. Also, it was demonstrated that the AU is an ‘As3+ target tissue.’ Otherwise, linking of the total concentrations of arsenic with conditional variables and variables related to medical geology factors allowed us to infer that the latter are more important for the cardiovascular risk of arsenic exposure in the Antofagasta region. Knowledge of total arsenic and the prevalence of the trivalent ion (As3+) in the AU of patients could contribute to understanding the effect of arsenic on cardiovascular diseases.

Inorganic Aspects of the Blood Chemistry of Ascidians. Ionic Composition, and Ti, V, and Fe in the Blood Plasma of Pyura chilensis and Ascidia dispar

Iron, titanium, and vanadium analysis were performed on the tunicates Pyura chilensis Molina, 1782, and Ascidia dispar, and the inorganic chemistry of blood was investigated. The major ionic characterization of the blood plasma and cytosolic solutions were determined. Gel chromatography was used to secure information on the possible existence of metal organic complexes.Pyura chilensis accumulates Fe and Ti, and Ascidia dispar accumulates Fe, Ti, and V in blood cells in this quantitative order. Significant levels of metals are associated with cell residues (membrane cells), although this may be, to some extent, dependent on the cell lysis technique.The elution behavior of plasma in Sephadex G-75 and LH-20 gels and the respective absorption spectra of the fractions showed evidence of organic metal complexes in the plasma of both tunicate species.

Variabilidad estacional de cadmio en un sistema de surgencia costera del norte de Chile (Bahía Mejillones del Sur, 23° S)

Entre junio de 2002 y abril de 2003 se midio el contenido de cadmio total y disuelto entre la superficie y los 100 m de profundidad, en dos estaciones localizadas en la bahia Mejillones del Sur. El rango de cadmio total y cadmio disuelto en las aguas de esta bahia fue 0,41-10,7 y 0,08-1,61 nM, respectivamente, durante el periodo de muestreo. Los resultados fueron correlacionados con la estructura fisico-quimica de la columna de agua al momento del muestreo, de manera de estudiar los patrones de variabilidad estacional de este metal en este sistema de surgencia. Las condiciones oceanograficas imperantes durante este periodo correspondieron a un ano normal (no-El Nino). Las masas de agua presentes en la bahia correspondieron a agua subantartica, subtropical y ecuatorial subsuperficial, con diferentes grados de mezcla y estratificacion durante el periodo de estudio. Los perfiles de cadmio presentaron una distribucion vertical clasica de un micronutriente. Sin embargo estos perfiles presentaron leves diferencias que pueden ser atribuidas a la condicion de mezcla de las masas de agua al interior de la bahia. Un analisis multivariado de los parametros registrados indico que la variacion temporal de cadmio en las aguas superficiales esta asociada a las fluctuaciones de la clorofila a y la temperatura. Esto sugiere que, a escala estacional, la produccion de biomasa fitoplanctonica seria el principal factor que controla la distribucion de cadmio en esta bahia. Por otro lado, a pesar de que el cadmio es un metal redox sensitivo no se encontro un efecto significativo de la disponibilidad de oxigeno sobre el comportamiento de este metal, de manera que la condicion microxica de las aguas de fondo de la bahia no seria un factor preponderante en el flujo de cadmio hacia los sedimentos. La razon Cd/PO4 encontrada en Mejillones es similar a la reportada en otras zonas costeras de Chile. Los bajos valores y la tendencia temporal observada en esta razon pueden ser explicados ya sea por una mayor eficiencia en la remocion de PO4 que de Cadmio en las aguas superficiales o una mayor remineralizacion de cadmio en las aguas subsuperficiales

Metal contents in coastal waters of San Jorge Bay, Antofagasta, northern Chile: a base line for establishing seawater quality guidelines

We measured the concentration of 12 metals in coastal waters of seven sites of San Jorge Bay in Antofagasta (northern Chile), in order to relate the presence of metals with the different uses of San Jorge Bay coastal border, and to evaluate the quality of the bay’s bodies of water according to the proposed current Chilean Quality Guide for trace elements in seawater (CONAMA 2003). The results suggest that the coastal water of San Jorge Bay has very good quality according to the proposed regulation mentioned above. However, the distribution of metals such as Cu and Pb along the bay’s coast line evidences a notorious effect of the industrial activity, which would involve different behavior patterns for some trace elements in some bodies of water, suggesting that the levels indicated in the environmental guideline of the Chilean legislation do not represent pollution-free environments.

Bioaccessibility and arsenic speciation in carrots, beets and quinoa from a contaminated area of Chile.

Consumption of vegetables grown in arsenic (As)-contaminated soils is an important exposure route to the element for humans. The present study is focused on locally-grown, frequently-consumed vegetables, such as carrots (Daucus carota), beets (Beta vulgaris) and quinoa (Chenopodium) from the As-polluted Chiu Chiu area in Northern Chile. The latter region is affected both by As discharge from copper mining activity and natural As contamination, leading to a high As content in local food and water. For the selected vegetables, the following aspects were investigated: i) Their total As, Cu, Pb, Cr, Cd and Mn content; ii) Arsenic speciation in the edible part of the vegetables by liquid chromatography inductively-coupled plasma mass spectrometry (LC-ICPMS) analysis; iii) Arsenic bioaccessibility in the vegetables during in vitro gastrointestinal digestion; iv) Arsenic species present in the extracts obtained from in vitro gastrointestinal digestion; and v) Arsenic dietary exposure estimates for the assessment of the risk posed by the vegetables consumption. A significant degree of As contamination was found in the vegetables under study, their metal content having been compared with that of similar Spanish uncontaminated products. In vitro gastrointestinal digestion of the studied vegetables led to quantitative extraction of As from carrots and beets, whereas efficiency was about 40% for quinoa. For carrots, only As(III) and As(V) species were found, being their concentration levels similar. In the case of quinoa, around 85% of the element was present as As(V). For beets, inorganic As(V) and unknown overlapped As species (probably arsenosugars) were found. No significant transformation of the original As species was observed during in vitro gastrointestinal digestion. Arsenic dietary exposure values obtained for the three vegetables (0.017-0.021μg As person(-1)day(-1)) were much lower than the JFCFAs safety limit of 50μg As person(-1)day(-1). Therefore, no toxicological risk would be expected from the intake of these vegetables.

Presencia de altos niveles de arsénico en tejidos cardiovasculares de pacientes de áreas contaminadas en Chile

En la Region de Anto-fagasta – Chile la contaminacion cronica por arsenico es causa de numerosas patologias donde se destacan las en-fermedades cardiovasculares. El presente estudio detalla la concentracion de arsenico total y sus principales espe-cies encontradas en tejidos cardiovasculares de pacientes que han requerido cirugia cardiaca. Se relacionan los niveles de As con hallazgos histologicos.

Bioavailability, Bioaccesibility of Heavy Metal Elements and Speciation of as in Contaminated Areas of Chile

Studies on the bioavailability of As, Cr, Cu, Pb, Mn and Cd of impacted soils; the As bioaccesibility in the edible parts of carrots, beets and quinoa growing in these polluted soils thought “in vitro” gastrointestinal process; the As speciation both in the edible parts of vegetables and in their gastrointestinal extracts have been performed. Elemental analysis and As speciation have been performed by ICP-MS and LC-ICP-MS, respectively. The high As contents in the interchangeable and oxidized fractions of soil may be responsible for the high As species content in these high vegetables consumption. The Arsenic recovery after the in vitro gastrointestinal digestion was from 98, 90 and 40% for carrots, beets and quinoa, respectively; with no significant transformation of original As species. These studies provide a clearer understanding of the impact that As and other contaminant elements may present in the population of this high polluted Chilean region

Trace metal variability in coastal waters of San Jorge Bay, Antofagasta, Chile: An environmental evaluation and statistical approach to propose local background levels

Between 2008 and 2011, twelve metals from 384 coastal waters samples from San Jorge Bay (Antofagasta, northern Chile) were collected and analyzed. The goal was to evaluate the quality of the bays water bodies according to the current Chilean Quality Guideline and to establish background levels for these metals. The result suggests that the coastal waters of San Jorge Bay are of very good quality suitable for recreational activities involving human body contact. The natural background thresholds established for this bay were significantly lower than primary and secondary water quality guidelines. The distribution of Cu, Zn and Pb, along the bays coastline provides evidence of the effects of industrial activity. Both situations suggest that the threshold indicated in the environmental guidelines of the Chilean legislation may be overestimated and do not represent pollution-free environments.