Biomonitores de la contaminación costera con referencia a las costas mexicanas: una revisión sobre los organismos utilizados

Approximately, since four decades ago, the environmental monitoring began in the marine and coastal environments, utilizing organisms, usually bivalve molluscs as a strategy to know the degree of pollution that prevailed in such ecosystems. Thus, by means of the analysis of tissues have been established the bioavailability and the concentrations of contaminants introduced in such environments (e.g. heavy metals, polycyclic aromatic hydrocarbons, organochlorine compounds, etc.). Moreover of bivalve molluscs, there are different groups of organisms that have been used for such purposes, which have been demonstrated to have certain characteristics suitable for their utilization as biomonitors. However, mussels, oysters and clams constitute a group that meet much of these features, and, therefore, there is an increased number of papers in the literature about the use of this group of organisms. In Mexico, several research groups have also used this biomonitoring strategy to evaluate the contamination of the coastal zone; various species have been identified to be used as biomonitors (e.g., Crassostrea gigas, C. iridescens, C. corteziensis, C. palmula, C. virginica, Mytilus californianus, Mytella strigata, Megapitaria squalida, Chione californiensis, Rangia cuneata and Polymesoda caroliniana), however, still relatively few studies have been conducted (38 papers from 1998 to 2010 in the Elseviers Scopus database) and there are even areas of the coastal zone where such studies are inexistent.Desde hace aproximadamente cuatro décadas se comenzaron a realizar estudios de monitoreo en los ambientes marinos y costeros utilizando organismos, generalmente moluscos bivalvos, como estrategia para tener un mejor conocimiento del grado de contaminación que prevalece en tales ecosistemas. Así, mediante el análisis de sus tejidos se han determinado la biodisponibilidad y las concentraciones de diversas sustancias (e.g., metales pesados, hidrocarburos aromáticos policíclicos, radionúclidos, compuestos organoclorados, etc.). Además de los moluscos bivalvos, existen diferentes grupos de organismos que se han empleado para tales fines, los cuales presentan ciertas características idóneas para su uso como biomonitores. Sin embargo, los mejillones, ostiones y almejas son el grupo que mejor cumple con una gran parte de estas características y, por lo tanto, de los que existe un mayor número de trabajos publicados. En México, se ha aplicado también la estrategia del biomonitoreo para evaluar la contaminación de la zona costera; se tienen identificadas varias especies que pueden ser utilizadas como biomonitores (e.g., Crassostrea gigas, C. iridescens, C. corteziensis, C. palmula, C. virginica, Mytilus californianus, Mytella strigata, Megapitaria squalida, Chione californiensis, Rangia cuneata y Polymesoda caroliniana), sin embargo, aún son relativamente pocos los trabajos que se han realizado (38 artículos de 1998 a 2010 en la base de datos Scopus de Elsevier) y hay, incluso, áreas de la zona costera en las que son inexistentes este tipo de estudios

An Economic Analysis of the Environmental Impact of PM2.5 Exposure on Health Status in Three Northwestern Mexican Cities

Introduction: This study provides an economic assessment of the health effects due to exposure to particulate matter PM2.5 in three medium-size cities of northwestern Mexico: Los Mochis, Culiacan and Mazatlán. People in these cities are exposed to high pollutant concentrations that exceed limits suggested in domestic and international guidelines. PM2.5 is an air contaminant negatively associated with people’s health when is highly concentrated in the atmosphere; its diameter is below 2.5 µm and causes the air to appear hazy when levels are elevated. To account for the economic impact of air pollution, a Health Impact Assessment (HIA) was used by the means of the European Aphekom Project. We figured the cost-savings of complying with current environmental standards and computed gains in life expectancy, total avoidable premature mortality, preventable cardiovascular disease, and the economic costs of air pollution related to PM2.5. A formal analysis of air pollution epidemiology is not pursued in this paper. Results: The cost of reducing PM2.5 pollution associated with negative health outcomes was based on two different scenarios: Official Mexican Standard (NOM, Spanish acronym) and World Health Organization (WHO) environmental standards. The mean PM2.5 concentrations in 2017 were 22.8, 22.4 and 14.1 µg/m3 for Los Mochis, Mazatlán and Culiacan, respectively. Conclusions: The mean avoidable mortality for all causes associated to PM2.5 exposure in these cities was 638 for the NOM scenario (i.e., with a reduction to 12 µg/m3) compared to 739 for the WHO scenario (reduction to 10 µg/m3). Complying with the WHO guideline of 10 µg/m3 in annual PM2.5 mean would add up to 15 months of life expectancy at age 30, depending on the city. The mean economic cost per year of the PM2.5 effects on human life in these three cities was USD 600 million (NOM scenario) and USD 695 million (WHO scenario). Thus, effective public health and industrial policy interventions to improve air quality are socially advantageous and cost-saving to promote better health.S

Eutrophication and macroalgal blooms in temperate and tropical coastal waters: Nutrient enrichment experiments with Ulva spp.

Receiving coastal waters and estuaries are among the most nutrient-enriched environments on earth, and one of the symptoms of the resulting eutrophication is the proliferation of opportunistic, fast-growing marine seaweeds. Here, we used a widespread macroalga often involved in blooms, Ulva spp., to investigate how supply of nitrogen (N) and phosphorus (P), the two main potential growth-limiting nutrients, influence macroalgal growth in temperate and tropical coastal waters ranging from low- to high-nutrient supplies. We carried out N and P enrichment field experiments on Ulva spp. in seven coastal systems, with one of these systems represented by three different subestuaries, for a total of nine sites. We showed that rate of growth of Ulva spp. was directly correlated to annual dissolved inorganic nitrogen (DIN) concentrations, where growth increased with increasing DIN concentration. Internal N pools of macroalgal fronds were also linked to increased DIN supply, and algal growth rates were tightly coupled to these internal N pools. The increases in DIN appeared to be related to greater inputs of wastewater to these coastal waters as indicated by high δ15N signatures of the algae as DIN increased. N and P enrichment experiments showed that rate of macroalgal growth was controlled by supply of DIN where ambient DIN concentrations were low, and by P where DIN concentrations were higher, regardless of latitude or geographic setting. These results suggest that understanding the basis for macroalgal blooms, and management of these harmful phenomena, will require information as to nutrient sources, and actions to reduce supply of N and P in coastal waters concerned.Fil: Teichberg, Mirta. Leibniz Center For Tropical Marine Research; AlemaniaFil: Fox, Sophia E.. Marine Biological Laboratory; Estados UnidosFil: Olsen, Ylva S.. Bangor University; Reino UnidoFil: Valiela, Ivan. Marine Biological Laboratory; Estados UnidosFil: Martinetto, Paulina Maria del Rosario. Universidad Nacional de Mar del Plata; ArgentinaFil: Iribarne, Oscar Osvaldo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Marinas y Costeras. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Marinas y Costeras; ArgentinaFil: Muto, Elizabeti Yuriko. Universidade de Sao Paulo; BrasilFil: Petti, Monica A.V.. Universidade de Sao Paulo; BrasilFil: Corbisier, Thaïs N.. Universidade de Sao Paulo; BrasilFil: Soto-Jiménez, Martín. Universidad Nacional Autónoma de México; MéxicoFil: Páez-Osuna, Federico. Universidad Nacional Autónoma de México; MéxicoFil: Castro, Paula. University Of Coimbra; BrasilFil: Freitas, Helena. University Of Coimbra; BrasilFil: Zitelli, Andreina. Università Iuav Di Venezia; ItaliaFil: Cardinaletti, Massimo. Gruppo Veritas; ItaliaFil: Tagliapietra, Davide. Consiglio Nazionale delle Ricerche; Itali

Diagénesis temprana de metales pesados en sedimentos del Pacífico adyacente a Ia boca del Golfo de California, Mexico

Con objeto de estudiar la partici6n geoquímica de los metales pesados, se utilizaron dos núcleos de sedimentos, procedentes de dos sitios adyacentes a la boca del Golfo de California en el Pacífico mexicano. Fueron separadas cinco fracciones operacionalmente definidas y las concentraciones de Cd, Cu, Co, Cr, Fe, Mn, Ni, Pb y Zn se determinaron en cada una de las muestras por técnicas de absorci6n atómica. Los resultados indican una conducta contrastante de las fases y los elementos asociadas durante la diagénesis temprana. Los datos de la fracción carbonatada, en el núcleo colectado en la depresión de la cuenca Mazatlán, permiten sugerir la formación de siderita (FeC03) con la profundidad de la columna sedimentaria, con la presencia del Pb como accesorio. Se propone un modelo simple para explicar la transferencia de las formas del Mn y Fe oxidable y reducible ala litogénica (silicoalurninatos); siendo esta transformaci6n de manera gradual y conforme se sepulta el material sedimentario, demostrándose un cambio concordante de tipo exponencial en las proporciones de los metales en las tres fases

Transporte de material sedimentario en el sistema lagunar de Altata-Ensenada del Pabellón, Sinaloa, México

Se evaluo el transporte de sedimentos como carga de fondo y en suspension en puntos discretos del sistema lagunar AltataEnsenada del Pabellon, México. Se determinaron perfiles verticales de concentraciones de sedimentos por medio de la integraci6n numerica de la ecuacion de difusion-conveccion promediada en el tiempo. El trabajo de campo y laboratorio incluyo mediciones de parametros fisicos (olas y corrientes) y sedimentarios. La informacion obtenida se uso como datos de entrada para el modelo de computadora desarrollado por Van Rijn (1-990). Los resultados indicaron en la mayoría de los perfiles verticales un incremento de las concentraciones con Ia profundidad. La mayor tasa de transporte de sedimentos en suspension (0.012 kg/s m2) se encontró cerca de Ia desembocadura del río Culiacan, mientras que la mayor tasa de transporte como carga de fondo (0.0012Kg/s m2) se determin6 en la entrada del sistema lagunar. Asimismo, se encontr6 que el flujo masico de sedimento suspendido es casi uniforme en las capas superiores de agua, incrementandose muy nipidamente a traves de Ia capa inferior de agua de aproximadamente 0.30 m de espesor, cercana al fondo. doi: https://doi.org/10.22201/igeof.00167169p.1994.33.2.47

Biomonitoring of arsenic through mangrove oyster (Crassostrea corteziensis Hertlein, 1951) from coastal lagoons (SE Gulf of California): occurrence of arsenobetaine and other arseno-compounds.

In this study, we examined the bioavailability of arsenic through the mangrove oyster Crassostrea corteziensis sampled from seven coastal lagoons in SE Gulf of California during the rainy and dry seasons. As concentrations in soft tissue of oysters C. corteziensis fluctuated between 5.2 and 11.6 μg/g on dry weight; organisms from the control site presented the lowest As concentrations in the two sampling seasons. As speciation was evaluated in selected samples and indicated that arsenobetaine was the major arseno-compound accounting for 53.5–74.7 % of total As. Lower percentage contributions were obtained for nonextractable As (9.7–25.5 %) and other molecules such as arsenocholine and methyl-arsonate (<5 %). Inorganic As was detectable in only two samples, at concentrations lower than 0.1 μg/g. These As data are the first generated in NW Mexico and indicate that C. corteziensis is safe for human consumption in terms of arseno-compounds. It is evident that As bioavailability in these lagoons is low

Macroalgal blooms in coastal lagoons of the Gulf of California eco-region: a summary of current knowledge

The Gulf of California is an important eco-region with 52 coastal lagoons that are affected by the different anthropogenic activities in their surrounding areas. Several studies in the region have reported seasonal changes in macroalgal biomass, and some have suggested that these changes may be associated with nutrient enrichment. However, research on macroalgal biomass increase has been done in only 27% of these coastal lagoons. In some species, biomass is related to high concentrations of nitrogen in the water column (in relation to phosphorus levels). Compared with other regions of the world, macroalgal biomass remains low here. More research is needed to establish clearer linkages between primary producers and nutrient sources associated with increasing human activities around the coastal lagoons of the Gulf of California