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1.
Arch Environ Contam Toxicol ; 86(2): 165-177, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38383775

RESUMO

The blue shark (Prionace glauca) is the most commonly caught species of Elasmobranchii at the entrance to the Gulf of California. Although fins are the primary target commodity, the entire organism is consumed. This study examined the concentration of Hg and Se in muscle and liver to understand the antagonistic process that occurs between these two elements within the organism. Twenty-two individuals were captured at the Gulf of California inlet between September 2019 and March 2021. Hg was measured by cold vapor atomic absorption, and Se by atomic absorption spectrophotometry in a graphite furnace. All individuals studied showed higher concentrations (µg g-1 wet weight) of Hg (0.69) and Se (2.49) in liver than in muscle (Hg 0.63 and Se 0.08). Although the mean Hg values were below the maximum allowable limits (Hg 1.0 µg g-1 wet weight), the molar ratio (< 1.0) and the negative health benefit value of selenium (HBVSe) in muscle show that additional caution should be taken when consuming this species. We recommend a more thorough study of the antagonistic interaction between Hg and Se to accurately assess the health risk for consumers of blue shark.

2.
Environ Geochem Health ; 45(7): 4533-4548, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-36853523

RESUMO

The failure of a tailings dam occurred in January 2013 at the Santa María de Otáez mining region (Mexico) released a spill (~ 300,000 m3) on Los Remedios River, which was transported through the San Lorenzo River, and finally to El Comedero (EC) dam. The concentrations of metal(loid)s in the muscle, liver, gills, and guts of three fish species (Cyprinus carpio, Oreochromis aureus, Micropterus salmoides) collected from EC dam were examined twenty months later to assess the performance of the cleaning operations. The bioaccumulation patterns of the metal(loid)s in the tissues were different in the three fish species. Tilapia had the highest Cd (11.23 ± 8.53 µg g-1) and Cu (871 ± 1261 µg g-1) concentrations in the liver, as well as As concentration (83.6 ± 61.7 µg g-1) in the gut, while the highest Zn concentration (745 ± 356 µg g-1) was measured in the gills of the carp. Such variability can be caused by the variant bioavailability of the metal(loid)s and by the feeding habits of each species; and also by the fact that some metals are essential and better regulated by organisms than other non-essential. Compared to a study of tilapia carried out 90 days after mine spill, a decrease was evident in the liver for As, Cd, Cu, and Zn by 129, 5, 10, and 1.7 times, respectively. This revealed that cleaning operations were more efficient for As. The target hazard quotient and the hazard index were < 1, which indicates there will be no risk of consuming muscle in moderated rations of the three fish species.


Assuntos
Carpas , Metais Pesados , Poluentes Químicos da Água , Animais , Metais Pesados/análise , Cádmio , Bioacumulação , Monitoramento Ambiental , Zinco/análise , Poluentes Químicos da Água/análise
3.
Environ Geochem Health ; 45(6): 3155-3169, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-36166169

RESUMO

In this study, the concentration of six metal(loid)s was examined in the fish Oreochromis aureus collected from El Comedero dam during a massive mortality event induced by a mine tailing spill. A major spill (~ 300,000 m3) of waste was released into the San Lorenzo River System following a rupture in the tailing dam of a mining plant in NW Mexico; consequently, the discharged material flowed into El Comedero dam. The accumulation of metal(oid)s in the tissues of O. aureus showed higher levels in the liver than in the guts and muscle. Concentrations in the liver were high (As, 1.1-1063; Cd, 8.9-392; Cu, 372-59,129; Hg, 0.46-19.79; Se, 8.7-748; and Zn, 116-820 µg g-1), revealing that these fish were exposed to high concentrations of these elements. The mortality of fish could have resulted from the combined effect of the six analyzed metal(loid)s, as well as other residues present in mine tailings.


Assuntos
Metaloides , Metais Pesados , Tilápia , Animais , Metaloides/toxicidade , Metaloides/análise , Monitoramento Ambiental , Metais/toxicidade , Metais/análise , Fígado , Metais Pesados/análise
4.
Environ Monit Assess ; 192(7): 417, 2020 Jun 06.
Artigo em Inglês | MEDLINE | ID: mdl-32506388

RESUMO

This study assessed the spatial and temporal nutrient variability in the El Fuerte River basin in northwestern Mexico, considering its effects on the water trophic status as well as the nutrient loading to the Gulf of California. Physicochemical parameters, inorganic species of nitrogen, phosphate, total nitrogen, total phosphorus, and chlorophyll-a (chl-a) were quantified at 16 selected sites along the river in April (dry season) and October (rainy season) 2017. Mean concentrations of nutrients during dry and rainy seasons were 36.3 ± 24.1 and 55.1 ± 74.6 µg L-1 of total ammonia nitrogen, 3.4 ± 3.6 and 4.5 ± 3.5 µg L-1 of NO2--N, 190.8 ± 256.0 and 163.6 ± 261.0 µg L-1 of NO3--N, 42.4 ± 44.2 and 104.9 ± 76.2 µg L-1 of PO43--P, 1.0 ± 1.3 and 691 ± 2242 mg L-1 of TN, 0.06 ± 0.06 and 0.08 ± 0.09 mg L-1 of TP, and 0.9 ± 0.6 and 2.0 ± 0.9 µg L-1 of chl-a with significant differences (p < 0.05) between sites and seasons. When waters are transported downstream, nutrient levels are enriched by 4 to 35 times compared to those upstream due to increased population and agriculture downstream, confirming the hypothesis of the study. The calculated TN and TP fluxes were 1.23 × 104 and 3.57 × 101 ton year-1, respectively. Factor analysis indicated that inorganic nitrogen species and phosphorus are the main factors affecting the river water quality. Despite N excess during the rainy season, the river reached mesotrophic waters due to phosphorus limitation. This suggests the need to establish a water quality monitoring program to understand the vulnerability of the river course to changes in its trophic state.


Assuntos
Monitoramento Ambiental , Nitrogênio , Fósforo , Rios , Poluentes Químicos da Água , Clorofila/análise , México , Nitrogênio/análise , Nutrientes/análise , Fósforo/análise , Rios/química , Estações do Ano , Poluentes Químicos da Água/análise
5.
Bull Environ Contam Toxicol ; 103(4): 515-520, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31143976

RESUMO

Concentration of essential (Se, Zn and Cu) and non-essential (As, Cd, Hg and Pb) trace elements were measured in selected tissues of two dead whale sharks (Rhincodon typus) stranded in the Gulf of California (GC) in 2017 and 2018. Concentrations of Cd and Pb in the skeletal muscle of the whale shark from La Paz Bay, GC were higher compared to a previous study on whale shark from China. The shark from La Paz Bay also presented higher concentration of Pb in the epidermis, compared to the same tissue of the other whale shark stranded in Punta Bufeo, GC. The Hg in all analysed tissues was lower than those documented in carnivorous sharks. Molar ratio Se:Hg shows an excess of Se over Hg in all the tissues sampled in both sharks.


Assuntos
Monitoramento Ambiental/métodos , Epiderme/química , Metais Pesados/análise , Músculo Esquelético/química , Tubarões/metabolismo , Oligoelementos/análise , Poluentes Químicos da Água/análise , Animais , Baías/química , México , Oceano Pacífico
6.
Environ Monit Assess ; 189(8): 395, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-28710691

RESUMO

This study evaluated the suitability of 21 inland waters (16 well waters and 5 surface waters) from Northwest Mexico via short- (48 h) and medium-term (28 days) tests using postlarvae (PL18) of Litopenaeus vannamei. In the short test, survival was assessed at 48 h after shrimp were placed in groups of 10 postlarvae into 2-L containers of inland water, to which they had been previously acclimated. The second, medium-term test consisted of four replicates with 10 postlarvae, and each group was placed in 15-L containers with the treatment water. Weights (initial and final) and survival were evaluated weekly for 28 days. In those waters for which the short test was positive and the medium-term test was negative and which also had a deficiency of potassium and/or magnesium, a third test was conducted. These last waters were supplemented with salts, and the shrimp survival and weights (initial and final) were recorded for 28 days. The water samples from San Jose, Mochicahui, Sinaloa River, Caimanero inner Lagoon, La Pipima, Campo Santa Fe, Escopama, and Fitmar had >60% survival in the short test. The Caimanero inner Lagoon water had the highest survival (87.5 ± 9.6%) and final mean weight (201.3 ± 86.2 mg). In the third test, it was found that shrimp in the water from La Pipima, Campo Santa Fe, and Fitmar exhibited 100% survival for 2 weeks. Finally, in this work, a decision tree to evaluate the suitability of low-salinity water for shrimp farming was proposed, which can be applied in other regions.


Assuntos
Monitoramento Ambiental , Penaeidae/fisiologia , Frutos do Mar , Água/química , Animais , Aquicultura , Suplementos Nutricionais , Magnésio/metabolismo , México , Penaeidae/crescimento & desenvolvimento , Potássio/metabolismo , Sais/metabolismo , Qualidade da Água
7.
Environ Monit Assess ; 189(2): 69, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-28116601

RESUMO

An experiment was developed to simulate inland shrimp farming using diluted seawater (1.9 g L-1) containing 75 shrimps (Litopenaeus vannamei) per square meter during a growth cycle of 120 days. In this study, the environmental loads of copper and zinc were estimated and compared to anthropogenic sources and shrimp aquacultures in other locations. Both metals resulted primarily from feeding, which accounted for 91.8% of Cu and 97.0% of Zn. Concentrations of Cu (110.8 ± 11.8 µg g-1) and Zn (69.0 ± 0.7 µg g-1) measured in the harvested shrimp had higher Cu and lower Zn concentrations compared to those reported for farmed shrimp from Brazil and Mexico. Clearly, organic sludge was the main route of removal for both metals (Cu 46.2%; Zn 92.6%). The annual environmental loads estimated for inland shrimp aquaculture were 598 ± 74 g Cu ha-1 and 5080 ± 328 g Zn ha-1.


Assuntos
Cobre/análise , Monitoramento Ambiental/métodos , Penaeidae/química , Frutos do Mar/análise , Poluentes Químicos da Água/análise , Zinco/análise , Animais , Aquicultura , Brasil , México , Água do Mar/análise , Qualidade da Água
8.
Bull Environ Contam Toxicol ; 94(5): 583-8, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25636437

RESUMO

Concentrations of arsenic (As), cadmium (Cd), copper (Cu), lead (Pb), mercury (Hg), silver (Ag) and zinc (Zn) were evaluated in water and suspended sediments of the upper waters of San Lorenzo River in NW Mexico following a mine tailing spill. Except As (6.64-35.9 µg L(-1)), dissolved metal concentrations were low (Ag <0.06-0.22; Cd 0.01-0.34; Cu 4.71-10.2; Hg 0.02-0.24; Pb <0.15-0.65; Zn 86-1,080 µg L(-1)) and were less than the upper limits established by UNEP (Water quality for ecosystem and human health, 2nd edn. United Nations Environment Programme Global Environment Monitoring System/Water Programme, Burlington, 2008), EPA (2014) and the Mexican regulation (NOM 1994). In contrast, the suspended metal concentrations were high (As 91.4-130; Ag 22.1-531; Cd 3.14-6.30; Cu 65-123; Hg 0.47-1.09; Pb 260-818; Zn 742-1,810 mg kg(-1)) and most of samples exceeded the probable effect level of the Canadian Sediment Quality Guidelines for the Protection of Aquatic Life.


Assuntos
Metais Pesados/análise , Mineração , Rios/química , Poluentes Químicos da Água/análise , Qualidade da Água , Metais Pesados/química , México , Poluentes Químicos da Água/química
9.
Artigo em Inglês | MEDLINE | ID: mdl-24007439

RESUMO

The purpose of this research is to provide a comprehensive assessment of the concentration levels and spatial variability of cadmium (Cd), copper (Cu), mercury (Hg), lead (Pb) and zinc (Zn) in El Tobari Lagoon in surface sediments during two seasons for several geochemical variables that could explain the observed heavy metal variability. Seventy-two surface sediments samples were collected in 12 different sites of the El Tobari Lagoon. Sediment samples were dried and subjected to acid extraction using a microwave system and five metals (Cd, Cu, Hg, Pb and Zn) were measured using atomic adsorption spectrometry. A certificate sediment material and blanks were used as quality control purposes. The enrichment factor (EF) and the index of geoaccumulation (Igeo) were calculated as index of metals contamination for the sediments, using aluminum as the conservative element. The five metals examined in sediments from El Tobari Lagoon exhibited a linear correlation with Al as result of the large specific surface areas of these sediment components and the chemical affinities between them. The metals contents in sites of the El Tobari Lagoon were variable, and Cd, Cu and Hg presented a seasonal behavior. The enrichment factor and index of geoaccumulation analysis indicated that Cd and Hg exhibited a certain extent (EF for Cd ranged from 4.10 to 10.29; EF for Hg ranged from 2.77 to 12.89) of anthropogenic pollution, while Cu showed sporadic (EF ranged from 0.43 to 2.54) anthropogenic contamination. The highest concentrations of Cd, Cu and Hg were found in the sites that regularly received discharge effluents from agriculture and aquaculture.


Assuntos
Sedimentos Geológicos/análise , Metais Pesados/análise , Poluentes Químicos da Água/análise , Agricultura , Alumínio/análise , Aquicultura , Monitoramento Ambiental , México , Análise de Regressão , Estações do Ano , Espectrofotometria Atômica
10.
Environ Monit Assess ; 185(2): 1071-85, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22527455

RESUMO

The Tobari Lagoon, located in the central-east coast of the Gulf of California, receives effluents from the Yaqui Valley, one of the most extensive agricultural areas of México. The Tobari Lagoon also receives effluents from nearby shrimp farms and untreated municipal sewage. Surface sediment samples and six different species of filter feeders (Crassostrea corteziensis, Crassostrea gigas, Chione gnidia, Anadara tuberculosa, Chione fluctifraga, and Fistulobalanus dentivarians) were collected during the dry and the rainy seasons and analyzed to determine concentrations of cadmium (Cd), copper (Cu), mercury (Hg), lead (Pb), and zinc (Zn). Seasonal variations in metal concentrations in sediment were evident, especially for Cd, Cu, Hg, and Zn. The total and bioavailable concentrations of the five metals are not elevated in comparison to other areas around the world. The percentages of bioavailable respect to total concentrations of the metals varied from 0.6 % in Hg to 50.2 % for Cu. In the organisms, Hg showed the lowest concentrations (ranged from 0.22 to 0.65 µg/g) while Zn showed the highest (ranged from 36.6 to 1,702 µg/g). Linear correlations between the levels of Cu, Pb, and Zn in the soft tissues of C. fluctifraga and C. gnidia, and A. tuberculosa and C. gnidia were found. Seasonal and interspecies variations in the metal levels in filter feeders were found; F. dentivarians, C. corteziensis, and C. gigas exhibited the highest levels, could be used as biomonitors of metals contamination in this area.


Assuntos
Monitoramento Ambiental , Invertebrados/metabolismo , Metais/metabolismo , Poluentes Químicos da Água/metabolismo , Animais , Aquicultura , Organismos Aquáticos/metabolismo , Bivalves/metabolismo , Ecossistema , Comportamento Alimentar , México , Poluição Química da Água/estatística & dados numéricos
11.
Bull Environ Contam Toxicol ; 91(1): 42-8, 2013 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-23595347

RESUMO

Hg was analyzed in seven tissues of 52 common shoveler Anas clypeata collected from the coast of SE Gulf of California. Mean Hg concentrations were highest in the liver (2,885 ng g⁻¹) and lowest in the gizzard (621 ng g⁻¹); they followed the order: liver, feathers > muscle tissue and tissues of the circulatory system > digestive organs. Hg levels were similar or higher than birds of the same trophic level and feeding habits. Considering the relationships of Hg among tissues and blood we recommend the use of blood as an efficient method to monitor Hg.


Assuntos
Patos/metabolismo , Exposição Ambiental , Monitoramento Ambiental/métodos , Mercúrio/sangue , Poluentes Químicos da Água/sangue , Animais , Cadeia Alimentar , Mercúrio/metabolismo , México , Espectrofotometria Atômica , Distribuição Tecidual , Poluentes Químicos da Água/metabolismo
12.
Arch Environ Contam Toxicol ; 61(2): 280-91, 2011 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-21082317

RESUMO

The objective of this investigation was to assess the transfer of lead (Pb) along an experimental, four-level food chain: Tetraselmis suecica (phytoplankton) â†’ Artemia franciscana (crustacean, brine shrimp) â†’ Litopenaeus vannamei (crustacean, white shrimp) â†’ Haemulon scudderi (fish, grunt). T. suecica was exposed to a sublethal dose of Pb in solution and then used as the base of a marine food chain. Significant differences in Pb concentrations were found between exposed organisms of the different trophic levels and the control. Particularly, Pb concentrations in fish of the simulated trophic chain were two-to three times higher in the exposed specimens than in the control. Levels of Pb in phytoplankton showed a substantial increase with respect to the solution (level I), with bioconcentration factors averaging from 930 to 3630. In contrast, a strong decrease in Pb concentration from phytoplankton to zooplankton (level II) and from zooplankton to shrimp tissues (level III) was evidenced by bioaccumulation factors <1. Despite the decrease in the assimilation efficiency of metal transfer observed in these two predators, Pb concentration in the grunt fish (level IV) was higher than in the shrimp (level III) (bioaccumulation factor >1.0). Some of the added Pb is transferred from the phytoplankton along the food chain, thus producing a net accumulation of Pb mainly in fish and, to a lesser extent, in shrimp tissues. Because Pb is one of the most pervasive contaminants in coastal ecosystems, its transference by way of diet and potential net accumulation in higher predators is of ecologic importance for marine life. In addition, because shrimp and adult Haemulon scudderi are commercially important resources, this issue is of particular relevance to the safety of marine products.


Assuntos
Artemia/metabolismo , Clorófitas/metabolismo , Cadeia Alimentar , Chumbo/análise , Penaeidae/metabolismo , Perciformes/metabolismo , Animais , Ecossistema , Monitoramento Ambiental/métodos , Chumbo/metabolismo , Fitoplâncton/metabolismo , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/metabolismo , Zooplâncton/metabolismo
13.
Bull Environ Contam Toxicol ; 86(6): 679-83, 2011 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-21516459

RESUMO

Total mercury and organic mercury were measured in ten fish species from the Mexican Pacific ocean to have a general view on the ratio of total mercury-organic mercury and potential implications on human health. Highest concentration of total mercury was recorded in muscle tissue of Carcharhinus leucas (0.62 µg g⁻¹ wet weight). Organic mercury was more concentrated in Haemulon sexfasciatum (0.4 µg g⁻¹ wet weight). Percentages of organic mercury ranged from 33 to 100%. Hazard indices associated to organic mercury and average fish consumption in Mexico ranged from 0.25 in Lutjanus colorado to 1.65 in Haemulon sexfasciatum.


Assuntos
Exposição Ambiental/estatística & dados numéricos , Peixes/metabolismo , Mercúrio/metabolismo , Compostos Orgânicos/metabolismo , Poluentes Químicos da Água/metabolismo , Animais , Exposição Ambiental/análise , Humanos , Mercúrio/análise , México , Compostos Orgânicos/análise , Oceano Pacífico , Alimentos Marinhos/análise , Alimentos Marinhos/estatística & dados numéricos , Poluentes Químicos da Água/análise , Poluição Química da Água/estatística & dados numéricos
14.
Bull Environ Contam Toxicol ; 86(2): 180-8, 2011 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-21234535

RESUMO

A hazard quotient (HQ) was evaluated for Mexican population considering Hg levels and consumption rates. Fish and shrimp were caught in selected coastal areas. HQ's ranged from 0.004 to 0.01 in shrimp; from 0.004 to 1.04 in fish from NW Mexico; and from 0.02 to 0.19 in fish from the Gulf of Mexico. Highest HQ in fish were found in carnivorous fish Caranx caninus (HQ = 0.71) and Sphyrna lewini (HQ = 1.04) from NW Mexico. A more accurate study should be made considering organic Hg, contribution of Hg from other sources, and consumption rates according to age, sex and economic status.


Assuntos
Dieta/estatística & dados numéricos , Exposição Ambiental/análise , Mercúrio/análise , Alimentos Marinhos/análise , Poluentes Químicos da Água/análise , Animais , Exposição Ambiental/estatística & dados numéricos , Monitoramento Ambiental , Peixes/metabolismo , Humanos , Mercúrio/metabolismo , México , Penaeidae/metabolismo , Medição de Risco , Alimentos Marinhos/estatística & dados numéricos , Poluentes Químicos da Água/metabolismo
15.
Environ Monit Assess ; 162(1-4): 251-63, 2010 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-19247791

RESUMO

With the aim of giving an overview on concentration and distribution of Cd, Cu, and Pb in fish from the coasts of Sinaloa state (SE Gulf of California), specimens with different feeding habits were collected in five locations. Sampling occurred between June 2003 and March 2004. Metal analyses on fish tissues were made by graphite furnace (Cd, Pb) and flame (Cu) atomic absorption spectrophotometry. Metal concentrations in tissues of carnivorous fish were grouped together and compared with corresponding concentrations in non-carnivorous fish; Cu and Pb levels were significantly (p < 0.05) higher in liver of non-carnivorous species. Though no samples exceeded the maximum level set in international legislation for fish, from the perspective of the public health and considering the legal limits of fishery products for human consumption, Cu concentrations were exceeded (in tissues different from muscle) in four carnivorous and five non-carnivorous species according to the Australian legislation. In the case of Cd, two carnivorous species (Pomadasys leuciscus and Caulolatilus princeps) and one non-carnivorous species (Mugil cephalus), showed concentrations over the maximum level of 2 microg g(-1) dry weight considered in the Mexican legislation. Considering average amounts of fish consumption in Mexico, daily mineral intake (DMI) values for Cu and percentage weekly intake (PWI) of Cd and Pb were estimated; none of the analyzed metals in edible portion of analyzed fish could be detrimental to humans.


Assuntos
Cádmio/análise , Cobre/análise , Peixes/metabolismo , Chumbo/análise , Poluentes Químicos da Água/análise , Animais , Cádmio/farmacocinética , Cobre/farmacocinética , Chumbo/farmacocinética , Água do Mar , Especificidade da Espécie , Espectrofotometria Atômica , Distribuição Tecidual , Poluentes Químicos da Água/farmacocinética
16.
Bull Environ Contam Toxicol ; 85(3): 339-43, 2010 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-20697884

RESUMO

In order to determine the mercury concentrations in cultured oysters from coastal lagoons (SE Gulf of California), several individuals of Crassostrea gigas and C. corteziensis were collected and their mercury levels were measured with a cold vapor analyzer. The mean concentrations during the rainy and dry seasons, respectively, were 0.70 and 0.15 microg g(-1) in C. gigas and 0.56 and 0.18 microg g(-1) in C. corteziensis. During the rainy season, elevated mercury contents are apparently related to terrigen transport from the watershed, while during the dry season, the moderate levels are related to upwellings.


Assuntos
Crassostrea/metabolismo , Monitoramento Ambiental , Mercúrio/metabolismo , Poluentes Químicos da Água/metabolismo , Animais , Aquicultura , México , Estações do Ano , Água do Mar/química
17.
Artigo em Inglês | MEDLINE | ID: mdl-20183507

RESUMO

With the objective of estimating the temporal variation and bioavailability of Cd, Cu, Pb and Zn in Coatzacoalcos estuary, the biota-sediment accumulation factors (BSAF) were calculated. For this purpose, surficial sediments and clams from 14 selected sites were collected during three climatic seasons. In surficial sediments, highest levels of Cd and Cu were measured during the rainy season near to the industrial area of Minatitlan, while highest concentrations of Pb and Zn were registered during the windy season in sediments collected near to the industrial area of Coatzacoalcos. Considering all the sampling seasons and bivalve species, average metal concentrations followed the order Zn > Cu > Cd > Pb. BSAF ranged from 0.01 (Pb) in Corbicula fluminea during the hot season to 25.1 (Cd) in Polymesoda caroliniana during the windy season. BSAF of Cd, Cu and Zn were higher during the windy season; in the case of Pb, the dry season was the time when such figure was more elevated. It can be stated that Polymesoda caroliniana is a net accumulator of Cd and Zn and a weak accumulator of Pb for the studied estuary.


Assuntos
Bivalves/química , Monitoramento Ambiental/estatística & dados numéricos , Poluentes Ambientais/análise , Sedimentos Geológicos/análise , Metais Pesados/análise , Petróleo , Animais , Indústrias Extrativas e de Processamento , México , Estações do Ano , Espectrofotometria Atômica
18.
Mar Pollut Bull ; 149: 110498, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31430665

RESUMO

Spatial and temporal variability of mercury concentrations in sediments was evaluated in 210Pb-dated sediment cores from offshore and intertidal areas in the southern Gulf of Mexico. In offshore cores, mercury concentrations were comparable (11.2-69.2 ng g-1), and intermediate between concentrations in intertidal cores from the eastern (6.0-34.4 ng g-1) and the western (34.9-137.7 ng g-1) inlets of Términos Lagoon. The enrichment factor (EF) indicated minimal contamination (EF < 2) in most offshore cores, whereas in some intertidal cores steadily increasing mercury enrichment and fluxes were observed along the past century. No evidence of oil industry related mercury contamination was found, as the minor but increasing enrichment in intertidal cores is most likely related to land-derived sources such as catchment eroded soils and waste water runoff. Results highlight the importance to control catchment erosion and untreated sewage releases to reduce mercury loadings to the coastal zone.


Assuntos
Monitoramento Ambiental/métodos , Sedimentos Geológicos/química , Mercúrio/análise , Solo/química , Poluentes Químicos da Água/análise , Golfo do México , Análise Espaço-Temporal
19.
Arch Environ Contam Toxicol ; 54(4): 584-96, 2008 May.
Artigo em Inglês | MEDLINE | ID: mdl-18027009

RESUMO

The aim of the work was to obtain a comparative view of the trophic distribution of Cd, Pb, and Zn in different organisms of the food web (from primary producers to top predators), considering representative species in Altata-Ensenada del Pabellón subtropical lagoon (SE Gulf of California). The study provides the first quantitative information on the biotransference of Cd, Pb, and Zn in a moderately contaminated lagoon ecosystem. After examination of 31 trophic interactions, 20 cases resulted in transference factors (TF) > 1.0 for Cd, 14 cases for Pb, and 18 cases for Zn. For Cd, most of the TF > 1 were found mainly among the low trophic levels (15 of 20 links); for Pb, most of the TF > 1 were found mainly among the high trophic levels (11 of 14 links), and for Zn, most of the TF > 1 were found mainly among the low trophic levels (14 of 18 links). This can be interpreted as partial evidence of biomagnification of Cd, Pb, and Zn for the species involved.


Assuntos
Ecossistema , Cadeia Alimentar , Água Doce/química , Metais Pesados/metabolismo , Poluentes Químicos da Água/metabolismo , Animais , Biotransformação , Aves/metabolismo , Exposição Ambiental , Eucariotos/química , Eucariotos/metabolismo , Peixes/metabolismo , Metais Pesados/análise , México , Penaeidae/química , Penaeidae/metabolismo , Frutos do Mar , Poluentes Químicos da Água/análise
20.
Environ Pollut ; 147(1): 282-90, 2007 May.
Artigo em Inglês | MEDLINE | ID: mdl-17267084

RESUMO

The tidal hydrodynamics of the Topolobampo coastal lagoon system (Mexico) has been investigated through a modified two dimensional non-linear hydrodynamic finite difference model. The advective and diffusive process acting over a hypothetical pollutant released into the coastal lagoon have also been simulated. Maxima tidal currents (0.85 m/s) were predicted within the main channel, in agree with direct measurements. The direction of the observed fastest currents (SW), also agree quite well with the direction of the strongest tidal current predicted in this investigation, which occur during the ebb when the water of the coastal lagoon is discharged into the Gulf of California. Residual currents (0.01-0.05 m/s) were also predicted. The hypothetical pollutant released within the Topolobampo Harbor would spread to both Ohuira and Topolobampo sections, reaching the inlet after approximately 12 days.


Assuntos
Ecologia/métodos , Modelos Teóricos , Poluição da Água , Água Doce , México , Água do Mar , Movimentos da Água , Purificação da Água
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