Sergio Ribeiro Guevara

Sergio Ribeiro Guevara
Bariloche Atomic Centre · Laboratorio de Análisis por Activación Neutrónica

Ph.D.

About

182
Publications
28,229
Reads
How we measure 'reads'
A 'read' is counted each time someone views a publication summary (such as the title, abstract, and list of authors), clicks on a figure, or views or downloads the full-text. Learn more
2,806
Citations
Introduction
Sergio researches nuclear techniques' applications in environmental research, particularly on heavy metals.
Additional affiliations
January 2012 - present
Comisión Nacional de Energía Atómica
Position
  • COMISIÓN NACIONAL DE ENERGÍA ATÓMICA
January 2016 - August 2017
Bariloche Atomic Centre
Position
  • Principal Investigator
January 2012 - present
Centro Científico Tecnológico - Patagonia Norte
Education
January 1996 - March 2001
Instituto Balseiro/Universidad Nacional de Cuyo y Centro Atómico Bariloche
Field of study
  • Nuclear Engineering

Publications

Publications (182)
Article
The study was carried out to determine Hg and Se concentrations in false killer whales stranded on the Estrecho de Magallanes, Chile, South America. Tissue samples of five mature specimens were analyzed (two females and three males). Mean Hg concentration in liver 1068 (234) μg g−1 dry weight (DW) (standard deviation in parenthesis) was markedly hi...
Article
Full-text available
Bromine (Br) to organic matter (OM) concentration ratio is studied in lake sediment sequences to provide information on environmental changes modifying OM production. The sequences studied were extracted from shallow lakes Morenito, El Trébol, Escondido, and Portezuelo; and deep lakes Futalaufquen, Moreno, and Traful (North Patagonia Andean range)....
Article
The dynamics of contaminants, such as mercury (Hg), in marine trophic webs is a critical topic in the scientific community due to the high concentrations encountered in organisms. In this study we attempted to provide information on total Hg accumulation patterns and possible pathways of trophic transfers assessed in combination with δ13C and δ15N...
Article
Full-text available
Atmospheric mercury measurements carried out in the recent decades have been a subject of bias largely due to insufficient consideration of metrological traceability and associated measurement uncertainty, which are ultimately needed for the demonstration of comparability of the measurement results.This is particularly challenging for gaseous HgII...
Article
A multiproxy analysis was conducted to determine the potential clay sources used in the production of archaeological pottery in the Characato region, Córdoba, Argentina. The results demonstrate that archaeological pottery production in Characato relied heavily on local clay sources rich in granitic aplastic inclusions and minimal material processin...
Article
Full-text available
The research focuses on the characterization of a tephra level extracted from sedimentary sequences obtained from three lacustrine environments from the northern Patagonia Andean range to define the volcano of origin. The dating of the tephra level corresponds to the mid-18th century but there is no scientific record nor geological evidence of this...
Conference Paper
Atmospheric mercury, specifically oxidized mercury (Hg II ), is the largest anthropogenic pool of mercury in the atmosphere. This type of mercury can accumulate in the food chain after undergoing methylation and entering ecosystems through wet and dry deposition. It is important to evaluate the level of wet and dry deposition, but measurements of a...
Article
Lacustrine environments from Northern Patagonia are exposed to volcanic events from the Southern Volcanic Zone. Chironomid larvae are an important paleo-proxy because, in addition to their environmental sensitivity, their chitinous cephalic capsules are well preserved in lacustrine sediments, allowing their recovery and identification. We analysed...
Article
Full-text available
This study analyzes the distribution of nine potentially toxic trace elements (arsenic, antimony, bromine, cobalt, chromium, mercury, rubidium, selenium, and zinc) in sediments and plankton from two small mesotrophic lakes in a non-industrialized area impacted by the Caviahue-Copahue volcanic complex (CCVC). The two lakes have different plankton co...
Book
Heavy metal pollution in the environment is a serious issue with ecological and economic implications, becoming a global issue in the biosphere as a consequence of the increasing anthropogenic impact in the last few decades. Because of their toxicity, persistence and bio-accumulative nature, heavy metals are hazardous to both terrestrial and aquati...
Article
Full-text available
Purpose The main objective of the study was to assess the environmental quality status of the sediments of eleven Patagonian lakes regarding the concentrations of five trace elements, evaluating the influence of volcanic activity and water and sediment parameters on element concentration and distribution. Materials and methods Surface sediment sam...
Book
Despite being an underpopulated region, Patagonia has attracted the attention of scientists since the very beginning of its settlement. From classical explorers such as Darwin or D´Orbigny, to modern science including nuclear and satellite developments, several disciplines have focused their efforts on unraveling Patagonia’s natural and social hist...
Chapter
Andean Patagonian catchments comprise large freshwater networks along a sharp west-to-east bioclimatic gradient. The Nahuel Huapi National Park (Argentina) includes the headwaters of the largest fluvial network of North Patagonia characterized by mountain and piedmont aquatic systems draining toward the Atlantic and Pacific oceans. Several studies...
Chapter
With the expansion of human settlements and the environmental changes brought on by human activity and pollutants toxicology and risk assessment of mammal species is becoming increasingly of interest to toxicologists involved in environmental research. This book focuses specifically on environmental risk assessment in marsupial and placental mammal...
Cover Page
Full-text available
Calibration for gaseous oxidized mercury species by nonthermal plasma oxidation of Hg0 to HgII species in the presence of O2/Cl2/Br2 gas.
Article
Full-text available
Macro-elements such as potassium (K), sodium (Na), chlorine (Cl), magnesium (Mg), and calcium (Ca) are essential in marine mammals’ nutrition. These elements are involved in physiological processes. Upon consumption, they are assimilated and accumulate in tissues. For the first time, they were detected in lung, spleen, liver, kidney, muscle, uterus...
Article
Full-text available
Volcanic eruptions represent one of the natural sources of Hg along with evasion from the oceans. This work evaluates the influence of these sources on the Hg bioaccumulation by fruticose lichens. The sampling areas were located in nearby sites affected by recent volcanic activity in the Patagonia Andean range. Geological techniques such as the stu...
Article
The aim of this work was to study the absorption, distribution through the hemolymph, and bioaccumulation of arsenic by the freshwater Pomacea canaliculata using a short-lived tracer (⁷⁶As, t1/2: 1.07 d) with high specific activity. Arsenic travels mainly dissolved in the plasma of the snail's hemolymph. This element is transferred from the hemolym...
Article
Full-text available
Atmospheric mercury speciation is of paramount importance for understanding the behavior of mercury once it is emitted into the atmosphere as gaseous elemental mercury (GEM), gaseous oxidized mercury (GOM) and particulate-bound mercury (PBM). GOM and PBM can also be formed in the atmosphere; their sampling is the most problematic step in the atmosp...
Preprint
Full-text available
Atmospheric mercury speciation is of paramount importance for understanding the behavior of mercury once it is emitted into the atmosphere as gaseous elemental (GEM), gaseous oxidized (GOM) and particulate-bound (PBM) mercury. GOM and PBM sampling are the most problematic steps in the analytical procedure. GOM sampling with speciation traps compose...
Article
Since the late-18 th Century, eye-witness accounts have documented a wide-spectrum of eruptive activity sourced from Volcán Calbuco located in northwest Patagonia. Despite these observations there is very little known about the eruptive products themselves that can account for this eruptive diversity. In this study, we examine the tephrostratigraph...
Article
Full-text available
Understanding atmospheric mercury chemistry is the key for explaining the biogeochemical cycle of mercury and for improving the predictive capability of computational models. Increased efforts are being made to ensure comparable Hg speciation measurements in the air through establishing metrological traceability. While traceability for elemental me...
Article
Full-text available
On a global scale, cetaceans are recognized well indicators of marine ecosystem health. Trace elements accumulate in their bodies and potentially constitute a toxicological threat. Here, the concentrations of essential Se; unknown physiological elements Br, Rb, Cs, Ni, and Sr; and pollutants arsenic, Cd, Hg, and Ag were assessed in the skin of fals...
Article
Lake sediments are key archives for paleoenvironmental investigation as they provide continuous records of the depositional history of the lake and its watershed. Lake Futalaufquen (42.8°S) is an oligotrophic waterbody located in Los Alerces National Park in the Andes of northern Patagonia, South America. A sedimentary sequence covering 1600 years...
Article
Full-text available
The atmospheric pollution associated with the volcano Copahue activity was evaluated by analyzing the concentration of 33 elements including heavy metals in lichens. Fruticose thalli were collected between 7 and 18 km from the volcano crater, comprising a geothermal zone. Analytical data and geographic parameters were evaluated by Principal Compone...
Article
Full-text available
Chironomid larvae assemblages and their seasonal variations were analyzed in several substrate types from Lake Moreno Oeste (Northern Patagonia) in order to understand the spatiotemporal patterns controlling its community. Information on the factors structuring chironomid communities is important to understand their ecological aspects and to improv...
Article
Mercury and heavy metal contents are monitored using lichens as a tool for evaluation of air pollution. Lichens allow the identification of zones with anthropic impact, pollution hotspots and natural sources of contamination like volcanic emissions. The concentration of mercury (Hg) semivolatiles and rare-earth elements (REEs) were measured in our...
Conference Paper
Full-text available
Keywords Patagonian Andes, aquatic systems, mercury in water, mercury speciation Nahuel Huapi National Park (NHNP) includes many freshwater oligotrophic ecosystems born in the Andes that are the main water source for the vast arid stretch of Northeastern Patagonia which holds most human settlements and activities of the region. In headwater catchme...
Conference Paper
Full-text available
A lo largo del milenio pasado se han identificado diferentes períodos climáticos en Patagonia: una época fría (1500-1700) asociada con la “Pequeña Edad de Hielo”, y un período más cálido y seco (1740-1900). Estudios previos afirman que los principales cambios en la comunidad pasada de quironómidos estuvieron asociados con los períodos climáticos qu...
Article
This work provides the first continuous measurements of atmospheric mercury (Hg) at the EMMA Station in Patagonia (Argentina), within the Southern Volcanic Zone of South America. This monitoring site was set up by the Global Mercury Observation System (GMOS project) and is located inside Nahuel Huapi National Park (41°07'43.33"S, 71°25'12.03"W; 800...
Thesis
The frequent eruptive activity from the Southern Volcanic Zone (SVZ) directly affects the sedimentation in adjacent areas, and the dominance of the westerlies in austral latitudes allowed the dispersion of pyroclastic products over Argentinean territory. The Nahuel Huapi National Park (NHNP) and surroundings are adequate places for the study of qua...
Article
Silver (Ag) is a non-essential metal known to bioaccumulate in aquatic organisms. We determined Ag concentrations in five false killer whales stranded in South America. Silver concentrations (in dry weight basis) range as 6.62-10.78 μg g −1 in liver, 0.008-7.41 μg g −1 in spleen, 0.004-5.71 μg g −1 in testis, 0.757-1.69 μg g −1 in kidney, 0.011-0.0...
Article
Response of Chironomidae to environmental disturbances in a high mountain lake in Patagonia during the last millennium – Corrigendum - Natalia Williams, Diego Añón Suárez, Maria Rieradevall, Andrea Rizzo, Romina Daga, María A. Arribére, Sergio Ribeiro Guevara
Article
Andean Patagonian lakes are oligotrophic systems characterized by low dissolved organic carbon (DOC) levels and moderate to high Hg concentration that determine naturally high Hg/DOC ratios and bioavailability. In these lakes, microbial food webs are extremely important in Hg trophodynamics, being that the picophytoplankton fraction is a major entr...
Article
Through the last millennium, Patagonia has been affected by changing climate conditions and successive volcanic eruptions. Lake Tonč ek is a high-altitude lake in the Southern Volcanic Zone in the northern Patagonian Andes. We documented the responses of the subfossil chironomid community to the effects of successive volcanic and different conditio...
Article
Interspecific differences in arsenic bioaccumulation and organ distribution (muscle, liver, kidney and gills) in three predator fish (creole perch, rainbow trout and brown trout) from a Patagonian lake impacted by volcanic eruptions were studied. Arsenic in fish organs were compared analyzing: 1) temporal (before and after volcanic eruption) and sp...
Conference Paper
Full-text available
Pyroclastic deposits from the eruptions of the Southern Volcanic Zone cover different landscapes and environments of the Andean and extra-Andean Patagonia due to the predominance of westerly winds at those latitudes. The variability, quantity and distribution of superficial and lacustrine environments within the Nahuel Huapi National Park (PNNH), a...
Article
Full-text available
Zinc (Zn) bioaccumulation and trophic transfer were analyzed in the food web of Lake Nahuel Huapi, a deep, unpolluted ultraoligotrophic system in North Patagonia. Benthic macroinvertebrates, plankton, and native and introduced fish were collected at three sites. The effect of pyroclastic inputs on Zn levels in lacustrine food webs was assessed by s...
Article
Microbial assemblages are typical of deep ultraoligotrophic Andean Patagonian lakes and comprise picoplankton and protists (phytoflagellates and mixotrophic ciliates), having a central role in the C cycle, primary production and in the incorporation of dissolved inorganic mercury (Hg2þ) into lake food webs. In this study we evaluated the mechanisms...
Article
Full-text available
Silver (Ag) is a pollutant of high concern in aquatic ecosystems, considered among the most toxic metallic ions. In lacustrine environments, contaminated sediments are a source of Ag for the food web. Chironomidae (Insecta: Diptera) are the most abundant, diverse, and representative insect groups in aquatic ecosystems. Chironomid larvae are closely...
Article
Pomacea canaliculata is a mollusk potentially useful as a biomonitor species of freshwater quality. This work explores the ability of snail tissues and symbiotic corpuscles to bioconcentrate and depurate mercury, arsenic, and uranium. Adult snails cultured in metal-free reconstituted water were exposed for eight weeks (bioaccumulation phase) to wat...
Article
Niche segregation between introduced and native fish in Lake Nahuel Huapi, a deep oligotrophic lake in Northwest Patagonia (Argentina), occurs through the consumption of different prey. Therefore, in this work we analyzed total mercury [THg] and methylmercury [MeHg] concentrations in top predator fish and in their main prey to test whether their fe...
Article
The crater lake and associated hydrothermal features of Copahue volcano have been studied intensively over the last 20 years (1995–2015). The geochemical and isotopic compositions of the waters provide insights into the processes occurring in the volcanic–hydrothermal system, the crater lake and the thermal springs. Variations in the temperature an...
Article
The limnological conditions during the past 700 yr were reconstructed based on multiproxy analysis of a short sedimentary sequence from El Toro Lake (~40°S, 70°W). Mineralogical and geochemical features, as well as ostracods and chironomids, record hydrologic changes in the El Toro Lake basin. The ostracod Limnocythere rionegroensis var. 1, a relia...
Article
Tuzla is among the most polluted cities of Bosnia and Herzegovina. The main source of pollution in the area is soil heavily contaminated by mercury released from a former chloralkali plant. This paper is focused on the characterization of mercury contaminated soil and air surrounding the chloralkali plant. In soil, the mobility and transformation o...
Article
Full-text available
The skin of cetaceans is the most accessible tissue, and its sampling has been proposed as a noninvasive method to evaluate trace element concentrations in free-ranging populations. In the present work, concentrations of essential (Cl, Na, K, Mg, Fe, Zn, Mn and Co), nonessential (As and Ag), and of unknown essentiality (Br, Rb and Cs) elements were...
Article
Despite located far from point sources of Hg pollution, high concentrations were recorded in plankton from the deep oligotrophic Lake Nahuel Huapi, located in North Patagonia. Native and introduced top predator fish with differing feeding habits are a valuable economic resource to the region. Hence, Hg and Se trophic interactions and pathways to th...
Article
Full-text available
The Global Mercury Observation System (GMOS) project, has developed a global-scale network of ground-based atmospheric monitoring sites, expanding the coverage of atmospheric mercury (Hg) measurements worldwide and improving the understanding of global atmospheric Hg transport and deposition, particularly in regions of the South Hemisphere where at...
Article
Copahue volcano has a record of historical eruptions of low intensity which have mainly been characterized from the events ob­served in last decades. Significant changes in several parameters associated with the volcano activity were observed since the end of 2011. After 12 years of quiescence, on July 2012, the volcano started a new eruptive perio...
Article
The Gulf of Trieste (northern Adriatic Sea) is considered as an important “natural bioreactor” that can be stimulated to increase sedimentary methylmercury (MeHg) production by mobilizing its extensive mercury (Hg) pool. Sediment samples, collected in the southern pristine, less contaminated, part of the gulf, were amended with radioactive ¹⁹⁷Hg in...
Article
Full-text available
Vegetation associated with lacustrine systems in Northern Patagonia was studied for heavy metal and trace element contents, regarding their elemental contribution to these aquatic ecosystems. The research focused on native species and exotic vascular plant Salix spp. potential for absorbing heavy metals and trace elements. The native species studie...
Article
Chironomid communities were studied in a sediment core collected from Lake Moreno Oeste, located in Nahuel Huapi National Park. A major change in midge assemblages occurred at ∼AD 1760, which was characterized by a decrease of “cold taxa” including Polypedilum sp.2 and Dicrotendipes, and an increase of “warm taxa” including Apsectrotanypus and Poly...
Article
Full-text available
The food web structure of the largest lake in northwest Patagonia, Lake Nahuel Huapi (area 557 km2), was investigated. Fish, benthic macroinvertebrates, plankton and primary producers were analyzed for stable nitrogen (δ15N) and carbon (δ13C) isotopes in three sites with contrasting morphometry and environmental characteristics. δ15N and δ13C revea...
Article
Full-text available
The species composition and the size structure of natural planktonic food webs may provide essential information to understand the fate of mercury and, in particular, the bioaccumulation pattern of Hg2+ in the water column of lake ecosystems. Heterotrophic and autotrophic picoplankton and phytoplankton are the most important entry points for Hg in...
Article
The incorporation and trophic transfer of total and methyl mercury (THg, MeHg) were examined in three size classes of plankton (10–53, 53–200, and > 200 µm size range) and a small planktivorous fish, Galaxias maculatus, from the large multi-branched Lake Nahuel Huapi (North Patagonia, Argentina). Three sites representing a large range of lake benth...
Conference Paper
Full-text available
Volcanic eruptions are important natural sources of arsenic (As) to the ecosystems. The Nahuel Huapi Lake, in northern Patagonia, was impacted by the eruption of the Puyehue-Cordón Caulle volcanic complex on June 4th, 2011. We investigated food web transfer patterns of As in the most affected shore of the lake (Brazo Rincón) and the effect of volca...