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Central obesity is known as an indicator of cardiometabolic risk, but better anthropometric measures than Body Mass Index (BMI) are needed to detect it. Waist-to-height ratio (WHtR) is an indicator of central adiposity and a strong predictor of cardiometabolic risk. OBJECTIVE: To determine the pre valence of cardiometabolic risk in a representative sample of Costa Rican children and adolescents. PATIENTS AND METHOD: Cross-sectional and descriptive study carried out with 2,684 students from 64 educational centers in Costa Rica. Validated questionnaires were applied to the students and their weight, height, and waist circumference were determined. Weight and body fat percentage of the students were determined with a Tanita model SC-331 S (without column). Height was measured with a SECA stadiometer model 217. The abdominal circumference was estimated using a tape mea sure. BMI and WHtR were calculated for each participant. The behavior of the indicator WHtR was analyzed with logistic regression models. All procedures were approved by the Ethics Committee of INCIENSA. RESULTS: There was a strong and positive correlation between waist circumference and BMI (r = 0.748, p < 0.001, 56% of shared variance), and a positive and moderate correlation between WHtR and BMI (r = 0.611, p < 0.01, 37% of shared variance). CONCLUSIONS: A third part of the stu dent population of elementary, middle, and high schools (31.8%) is at cardiovascular and metabolic risk.

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In aquatic ecosystems, the complex mixture of pollutants may mediate the formation of free radicals and cause oxidative damage to the biota. Yuriria Lake (a Ramsar site in Central Mexico) receives input of wastewater from its tributaries, agricultural runoff, and municipal discharge. We studied the lipid peroxidation (LPO), antioxidant enzymes (superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx), and histopathology of gill and liver of the native fish Goodea atripinnis in Yuriria Lake. Results were compared to a control group of fish cultivated in the laboratory. LPO, SOD, and CAT showed no significant differences compared to controls, but GPx showed greater and significant differences in both tissues. Three class sizes were identified; organisms of classes I and II had slight vasocongestion in the liver as compared to controls. Hepatocytes of class III showed cytoplasmic vacuolization, cellular disorganization, and the liver showed marked fibrosis compared to controls. Gills of controls and classes I and II showed no damage in gill filaments. Tissue damage in class III included hypertrophy, loss of the typical morphology, and edema in the gill filaments. The longer exposure of older organisms to Yuriria Lake conditions may have resulted in their poorer health condition...

En los ecosistemas acuáticos, la mezcla compleja de contaminantes presente puede mediar la producción de radicales libres y causar daño por estrés oxidativo a la biota. La laguna de Yuriria (sitio RAMSAR en la parte central de México) recibe aguas residuales de sus afluentes, escorrentías agrícolas y descargas municipales. Se estudió la peroxidación lipídica (LPO), las enzimas antioxidantes superóxido dismutasa, (SOD), catalasa (CAT) y glutatión peroxidasa (GPx); y la histopatología de las branquias e hígado del pez nativo Goodea atripinnis en la Laguna de Yuriria. Los resultados obtenidos fueron comparados con un grupo control de peces cultivados en laboratorio. La LPO, SOD y CAT no mostraron diferencia significativa en comparación con los controles; pero la GPx mostró diferencias significativas para ambos tejidos. Se identificaron tres clases de talla; los organismos de la clase I y II tuvieron una ligera vasocongestión en el hígado en comparación con los controles. Los hepatocitos de la clase III mostraron vacuolización citoplásmica, desorganización celular y el hígado mostró una marcada fibrosis. Las branquias de los organismos control y de las clases I y II no mostraron daño en sus filamentos. El daño tisular en los organismos de la clase III incluyó hipertrofia, pérdida de la morfología típica y edema en los filamentos branquiales. La exposición prolongada a las condiciones de la Laguna de Yuriria pudo haber influido en el precario estado de salud de los organismos más longevos...

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The aim of this study was to determine the efficiency of Dugesia dorotocephala on Methyl parathion removal. An initial concentration of 1.25 microg mL(-1) of MeP was used to evaluate the removal capacity of planarian. A first-order removal kinetics was obtained with a disappearance rate constant (k(r)) of 0.49 days(-1) and 69% efficiency on contaminant removal. This is significantly different (p < 0.5) from the degradation occurring in control systems, leading us to conclude that D. dorotocephala effectively removes MeP from contaminated water.

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Methyl parathion (MeP) is a very hazardous pesticide freely used in agriculture in Mexico. This pesticide and others, arriving through different processes, exert significant effects on water quality with serious consequences for environmental and human health. This study evaluates the removal efficiency of common cattail Typha latifolia L. on MeP in water and artificial sediments. The effects of the pesticide on this macrophyte after 10 days of exposure were determined using a concentration range of 0-200 mg l(-1), 198.1+/-1.79 g average biomass, pH 7.0, 18-22 degrees C temperature and natural daylight/darkness periods, using chlorophyll production as a biomarker. Removal kinetics were conducted under similar conditions on days 0, 3, 7, 9, 11 and 14 of exposure, using 6 mg l(-1) in each system. Pesticide concentration, chlorophyll content and glutathione S-transferase (GST) activity were quantified. Results show a high removal efficiency of cattails on MeP in water and sediments relative to controls. An increase in GST activity and a decline in chlorophyll content in the test systems were not significantly different relative to controls. Cattails may thus be a good candidate for development of a phytoremediation system for MeP-contaminated water and artificial sediments.

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This paper presents toxicity and uptake data of Limnodrilus hoffmeisteri generated by lead in systems using natural sediments from Ignacio Ramírez reservoir. Lead uptake, hemoglobin concentration, and acetylcholinesterase activity were studied in L. hoffmeisteri exposed to spiked sediments. All assays of lead uptake were conducted using whole sediments. Sediment texture was also considered. Acetylcholinesterase activity and hemoglobin concentration decreased after treatment with lead. Acetylcholinesterase activity and hemoglobin concentration tests indicated a response to the concentration of lead. These results suggest the usefulness of a diversity of bioassays to evaluate the toxicity of sediments polluted with heavy metals.

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/ The Río Grande de Morelia-Lago de Cuitzeo basin in west central Mexico has experienced major increases in water pollution from a rapidly growing human population. We examined changes in the long-term distribution of fishes in relation to water quality and quantity in order to assess the condition and health of aquatic ecosystems inthe basin. Sampling between 1985 and 1993 revealed that five (26%) of the 19 native fish species known from the basin had been extirpated. Two of these were endemics, Chirostoma charari and C. compressum, and they are presumed extinct. Twelve (63%) of the remaining species had declines in distribution. Sixteen (80%) of the 20 localities sampled had lost species. The greatest declines occurred in Lago de Cuitzeo proper and in the lower portion of the Río Grande de Morelia watershed. Species losses from the lake were attributable to drying and hypereutrophication of the lake because of substantial reductions in the amount and quality of tributary inputs, whereas losses from the Río Grande de Morelia watershed were the result of pollution from agricultural, municipal, and industrial sources, especially in the region around the city of Morelia. Three localities in the upper portion of the Río Grande de Morelia watershed-Cointzio reservoir, La Mintzita spring, and Insurgente Morelos stream-contained most of the remaining fish species diversity in the basin and deserve additional protection. Fish faunal changes indicated major declines in the health of aquatic ecosystems in the Morelia-Cuitzeo basin.KEY WORDS: Fish distribution; Río Lerma; Ecosystem health; Water quality; Chirostoma; Threatened and endangered specieshttp://link.springer-ny.com/link/service/journals/00267/bibs/24n1p133.html

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Chlorodiphenylnitrichloroethane (DDT) and chlordane (CLO) are currently used in Mexico to control malaria and termites. From 1990 to 1996 a total of 27 ton of DDT and 508 of CLO were imported. We establish a methodology to determine their environmental impact in a Mexican dam (Ignacio Ramírez). The toxic effect of DDT and CLO were evaluated on the o-demethylase (OD) and acethycholinesterase activities (AchA) of the cladoceran Daphnia magna exposed to different concentrations of the insecticides solved in water from three sites. Their effect on the AchA and OD activities, and so the CL50 were used as exposure bioindicators to determine the more polluted sites. The physicochemical characteristics of water and the biodiversity of the dam test sites were considered. The station near the floodgate has toxicity potential because enzymatic activities were modified. We suggest the use of AchA and OD activities measure in the cladoceran to evaluate the toxicity of a water body polluted by organochlorate insecticides.

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