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1.
Ecotoxicology ; 32(2): 166-187, 2023 Mar.
Article in English | MEDLINE | ID: mdl-36689067

ABSTRACT

Aquatic ecosystems have been suffering deleterious effects due to the development of different economic activities. Metal(loid)s are one of the most persistent chemicals in environmental reservoirs, and may produce adverse effects on different organisms. Since fishes have been largely used in studies of metal(loid)s exposure, tilapia and largemouth bass were collected in three ecosystems from the Yaqui River Basin to measure the concentrations of metal(loid)s (chromium (Cr), copper (Cu), iron (Fe), manganese (Mn), nickel (Ni), zinc (Zn) arsenic (As), mercury (Hg), and selenium (Se)) and some biomarkers (somatic indices, metallothionein expression and histopathological analysis) in tissues of both species. Metal(loid) concentrations varied seasonally among ecosystems in tissues of both species. The elements varied seasonally and spatially in tissues of both species, with a general distribution of liver > gills > gonads. Also, biomarkers showed variations indicative that the fish species were exposed to different environmental stressor conditions. The highest values of some biomarkers were in largemouth bass, possibly due to differences in their biological characteristics, mainly feeding habits. The multivariate analysis showed positive associations between metal(loid)s and biomarkers, which are usually associated to the use of these elements in metabolic and/or regulatory physiological processes. Both fish species presented histological damage at different levels, from SI types (changes that are reversible for organ structure) to SII types (changes that are more severe but may be repairable). Taken together, the results from this study suggest that the Yaqui River Basin is moderately impacted by metals and metalloids.


Subject(s)
Bass , Cichlids , Mercury , Tilapia , Water Pollutants, Chemical , Animals , Bass/metabolism , Ecosystem , Rivers/chemistry , Mexico , Environmental Monitoring/methods , Metals/metabolism , Mercury/analysis , Biomarkers/metabolism , Water Pollutants, Chemical/analysis
2.
Arch Environ Contam Toxicol ; 83(1): 36-46, 2022 Jul.
Article in English | MEDLINE | ID: mdl-35690954

ABSTRACT

To balance the risks and benefits of fish consumption, selenium, fatty acids (DHA + EPA), and mercury in fishery products were determined. Analyzed products were canned tuna, frozen tuna (Thunnus albacares), smoked striped marlin (Tetrapturus audax), fresh Pacific sierra (Scomberomorus sierra), fresh dolphinfish (Coryphaena hippurus), fresh tilapia (Gerres cinereus), and fresh bullseye puffer (Sphoeroides annulatus). Mercury (µg g-1 wet weight) ranged from 0.01 (dolphinfish) to 0.23 (bullseye puffer); Se ranged from 0.12 to 0.25. EPA + DHA ranged from 1.16 to 10.72 mg g-1. Intake of EPA + DHA was comparable or above the recommended daily intake; Hg intake was below the reference dose but Se intake was below than recommended values for the different population groups. Considering the HBVSe, fishery products had positive values; i.e., they are healthy food items. According to the interaction of Hg and Se and the rate of fishery product consumption, the risk for consumers is below one percent.


Subject(s)
Mercury , Selenium , Animals , Fatty Acids , Fishes , Mercury/analysis , Mexico , Risk Assessment , Seafood , Selenium/analysis , Tuna
3.
Environ Monit Assess ; 194(7): 466, 2022 Jun 01.
Article in English | MEDLINE | ID: mdl-35641703

ABSTRACT

Marine ecosystems are subject to contamination by metals and metalloids and other elements and compounds that are emitted due to various human activities. These substances subsequently induce changes in marine biota after entering the marine environment. Marine organisms are frequently consumed worldwide because they constitute relatively cheap and accessible food items of high nutrient quality. The aim of this study was to estimate metal accumulation in frequently consumed marine species and to evaluate the associated health risks for particular population groups in a coastal region of northwestern Mexico. The marine species were consumed in different quantities between spring (from 0.29 kg year-1 for white clam, to 38.40 kg year-1 for blue crab) and autumn (from 0.34 kg year-1 for white clam, to 15.02 kg year-1 for leopard grouper). The general distribution of metal concentrations in the marine species (n = 13 in each season) evaluated in this study followed the trend of Fe > Zn > Cu > Mn > Cr with the highest metal concentrations detected during autumn. Although many metal concentrations were above the international standards of the Food and Agriculture Organization of the United Nations (FAO) and the World Health Organization (WHO), the hazard quotient (HQ) and hazard index (HI) values for the women in this study indicated that their health was not at risk due to the consumption of either fish or seafood. In contrast, the HQ and HI values determined for groups of men and children indicated that they are at risk due to the frequent consumption of most species evaluated in this study.


Subject(s)
Environmental Monitoring , Water Pollutants, Chemical , Animals , Biota , Ecosystem , Female , Humans , Metals/analysis , Mexico , Risk Assessment , Water Pollutants, Chemical/analysis
4.
Environ Sci Pollut Res Int ; 28(40): 56175-56187, 2021 Oct.
Article in English | MEDLINE | ID: mdl-34050511

ABSTRACT

The biomagnification of Hg and Se was studied using nitrogen stable isotope analysis during four seasons in a coastal lagoon of the eastern central Gulf of California. This lagoon receives agricultural, municipal, and shrimp aquaculture effluents. The species were categorized into organism groups and presented a significant accumulation of Hg and Se with respect to the sources, while the concentration of both elements in sediment and suspended particulate matter (SPM) was low. Our data confirms the positive transfers (biomagnification factors >1) of Hg and Se in the entire studied food web, and it was structured in five trophic levels across all seasons. Additionally, there were no linear correlations between the molar Se:Hg ratios and the trophic levels of the organism groups. However, the Se:Hg ratios among organism groups were >1, which indicates that there is an excess of Se and that it is not a limiting factor for the detoxification of Hg.


Subject(s)
Mercury , Selenium , Water Pollutants, Chemical , Agriculture , Animals , Aquaculture , Bioaccumulation , Environmental Monitoring , Fishes , Food Chain , Mercury/analysis , Selenium/analysis , Water Pollutants, Chemical/analysis
5.
Environ Sci Pollut Res Int ; 28(13): 16895-16912, 2021 Apr.
Article in English | MEDLINE | ID: mdl-33398728

ABSTRACT

Water reservoirs are essential for regional economic development, as populations depend on them for agriculture irrigation, flood control, hydroelectric power generation, water supply for human consumption, and subsistence fishing activities. However, the reservoir environmental quality can be disturbed by enhanced sediment input and trace metal contamination, affecting human health as a consequence of contaminated water and fish consumption. With the purpose to understand the trends and extent of sediment accumulation and trace element contamination in the Oviachic reservoir (OV, northwestern Mexico) since its construction, the temporal variations of sediment accumulation, and As, Cr, Cu, Hg, Ni, Pb, and Zn concentrations, enrichment, and fluxes, were evaluated through the study of two 210Pb-dated sediment cores. We assumed that siltation and trace element contamination were driven by the development of anthropogenic activities in the region within the past ~ 70 years. Elemental concentrations accounted from null to minor enrichment for most elements, but moderate to significant enrichment by Hg. Mercury, As, and Cu fluxes have notably increased since the past decade, most likely because of a combination of anthropogenic and natural processes, including catchment erosion, artisanal gold mining, and recent drought conditions in the region. Arsenic and Hg concentrations may pose deleterious risks to biota in the reservoir, and consequently to humans through fish consumption, for which further biological and toxicological tests are advisable. This study highlights the importance of using sediment dating to assess historical trends of metal contamination and identify possible sources, to support decision-making in programs addressed to reduce environmental and health risks in aquatic ecosystems.


Subject(s)
Metals, Heavy , Trace Elements , Water Pollutants, Chemical , Animals , Ecosystem , Environmental Monitoring , Geologic Sediments , Humans , Metals, Heavy/analysis , Mexico , Trace Elements/analysis , Water , Water Pollutants, Chemical/analysis
6.
Biol Trace Elem Res ; 199(8): 3112-3125, 2021 Aug.
Article in English | MEDLINE | ID: mdl-33058041

ABSTRACT

In the present paper, we investigated the accumulation of six metals in tilapia (Oreochromis nilocticus) and largemouth bass (Micropterus salmoides) as indicators of the environmental pollution present at three constructed dams in the Yaqui River basin in Sonora, Mexico. The La Angostura (ANG), El Cajon de Onapa (ECO), and El Oviachic (OVI) dams are ecosystems under different degrees of anthropogenic stress. The collected fishes were dissected to obtain liver, gonad, stomach, gill, and muscle samples to determine the metal concentrations of Fe, Mn, Ni, Cu, Zn, and Cr. The results of a PERMANOVA showed that the concentrations of Fe, Cu, and Zn were significantly higher in tilapia liver, stomach, and gill tissues compared with those of the largemouth bass. Also, differences were detected between seasons, with the metal concentrations during the dry season being significantly higher than those of the rainy season (p < 0.001). The results of a principal component analysis showed an association between metals, tissues, and dams with significantly higher (p < 0.001) concentrations in tilapia from the ECO dam compared with those from the ANG and OVI dams. The general distribution of metals in the tissues was as follows: liver > stomach-gills > gonads > muscle. Variations in metal concentrations may be indicative of the different sources of anthropogenic stress in each ecosystem.


Subject(s)
Bass , Metals, Heavy , Tilapia , Water Pollutants, Chemical , Animals , Bioaccumulation , Ecosystem , Environmental Monitoring , Metals, Heavy/analysis , Mexico , Rivers , Water Pollutants, Chemical/analysis
7.
Environ Sci Pollut Res Int ; 27(14): 16774-16783, 2020 May.
Article in English | MEDLINE | ID: mdl-32133613

ABSTRACT

Mercury and selenium were assessed in Mustelus henlei, which is a carnivorous predatory shark that is important for the coastal communities of the northern Mexican Pacific (NMP). Sixty-two individuals were sampled; muscle and liver were isolated and analyzed by atomic absorption spectrophotometry. The mean Hg concentrations (wet weight) obtained for muscle (0.08 ± 0.10 µg g-1) and liver (0.09 ± 0.26 µg g-1) were below the allowed limits (< 1.0 µg g-1 Hg). The average Se concentration was 0.03 ± 0.01 µg g-1 in muscle and 0.13 ± 0.05 µg g-1 in liver. The Se/Hg molar ratio of muscle was 1.83; however, the selenium health benefit value (HBVSe) was of 0.08. We calculated that an adult man (70 kg), an adult woman (60 kg), and a child (16 kg) could consume 1595, 838, and 223 g/week of M. henlei muscle, respectively, without risks to health. In conclusion, the concentrations and molar ratio of Hg and Se in M. henlei muscle mean that consumption of this shark's meat does not represent neither a benefit nor a public health risk.


Subject(s)
Mercury/analysis , Selenium/analysis , Sharks , Water Pollutants, Chemical/analysis , Animals , Child , Environmental Monitoring , Female , Humans , Male , Mexico
8.
Environ Sci Pollut Res Int ; 27(5): 5323-5336, 2020 Feb.
Article in English | MEDLINE | ID: mdl-31845275

ABSTRACT

We studied the biomagnification of cadmium (Cd), copper (Cu), lead (Pb), and zinc (Zn) with carbon (C) and nitrogen (N) stable isotope analyses during four seasons, in the food web of a semiarid coastal lagoon in the central-eastern Gulf of California (GC). The concentrations of the four metals increased among functional organism groups, from the food web base to the highest trophic levels. In general, the distribution of the elements for the four sampled seasons was Zn > Cu > Pb > Cd. The correlations between trophic level values and log-transformed metal concentrations were significantly (p < 0.05) positive for Cd (r = 0.61-0.91), Cu (r = 0.63-0.70), and Zn (r = 0.50-0.73), while Pb showed only one positive correlation (r = 0.38). The biomagnification factors (from specific predator-prey scenarios) ranged from 0.32 to 3.88 for Cd, 0.05 to 37.1 for Cu, 0.50 to 3.57 for Pb, and 0.70 to 22.2 for Zn. The trophic biomagnification factors (considering the entire food web) varied from 1.26 to 1.41 for Cd, 1.95 to 2.24 for Cu, 1.02 to 1.15 for Pb, and 1.45 to 1.78 for Zn. Our results show evidence for the biomagnification of Cd, Cu, and Zn in the studied food web, while data on Pb transference are not conclusive.


Subject(s)
Agriculture , Environmental Monitoring , Metals, Heavy , Water Pollutants, Chemical , Animals , Aquaculture , Bioaccumulation , California , Ecosystem , Metals
9.
Environ Sci Pollut Res Int ; 27(2): 2311-2318, 2020 Jan.
Article in English | MEDLINE | ID: mdl-31776904

ABSTRACT

With the aim of determining the benefit from consumption of dolphinfish Coryphaena hippurus from La Paz and Cabo San Lucas in the southern area of the Gulf of California, mercury (Hg) and selenium (Se) were measured in liver and muscle of specimens (n = 362) collected between 2006 and 2013. Mean levels of Hg in muscle (0.61 µg g-1) and liver (0.42 µg g-1) of all individuals from La Paz were significantly higher (p < 0.05) than in fish from Cabo San Lucas; in the case of Se, mean concentrations in liver (1.54 µg g-1) of all individuals from La Paz were significantly higher (p < 0.05) than in fish from Cabo San Lucas. Hg levels in muscle were positively and significantly (p < 0.05) correlated with fork length and weight of fish; in liver, Hg and Se were significantly (p < 0.05) correlated with fork length and weight of specimens. Levels of Hg and Se in muscle and liver among years varied significantly (p < 0.05); although there was not a defined pattern of temporal fluctuations for both elements, the lowest Hg levels occurred in 2009 when surface water temperatures were the highest for the sampled years. With respect to the Se health benefit value (HBVSe), results were positive and above the unit in all cases; it implies that consumption of dolphinfish in the southern Gulf of California is beneficial.


Subject(s)
Mercury/analysis , Perciformes , Selenium , Water Pollutants, Chemical , Animals , California , Environmental Monitoring , Female , Male , Mercury/chemistry , Perciformes/metabolism , Selenium/analysis , Selenium/chemistry , Selenium/metabolism
10.
Sci Total Environ ; 664: 635-646, 2019 May 10.
Article in English | MEDLINE | ID: mdl-30763844

ABSTRACT

In this study, we elucidated the impacts of allochthonous organic matter (OM) and nutrients (N and P) inputs coming from agriculture and shrimp aquaculture activities on food web structure in a subtropical coastal lagoon located on the central-east of the Gulf of California. This coastal lagoon is highly influenced by OM and nutrients inputs by a large agriculture district and aquaculture development center in Mexico. We also selected a second coastal lagoon, without direct OM and nutrients inputs, considered as a 'pristine' ecosystem. We evaluated the quantity of OM, N and P in both ecosystems and reconstructed the food webs using isotopic tools of C and N from the base to top. We collected and analyzed autochthonous and allochthonous OM, and organisms including primary producers, and primary to tertiary consumers. Overall, specimens of the same species and/or functional groups showed higher δ15N values in the ecosystem receiving agriculture and shrimp aquaculture effluents than the pristine. Food webs were composed of four and five trophic levels, where fish and birds occupied the top-predator levels. Seasonal increases in OM and N and P quantities in lagoons affected by anthropogenic activities produced high δ15N values in primary producers and consumers.


Subject(s)
Agriculture , Aquaculture , Environmental Monitoring , Water Pollutants, Chemical/analysis , Animals , California , Crustacea , Ecosystem , Food Chain , Mexico , Nitrogen/analysis , Phosphorus/analysis
11.
Environ Monit Assess ; 187(11): 700, 2015 Nov.
Article in English | MEDLINE | ID: mdl-26497560

ABSTRACT

With the aim of determining arsenic (As) and selenium (Se) concentrations in bycatch fishes from SW Mexico and comparing elemental concentrations with limits for human consumption set in the national and international legislation, three fish species (Diapterus peruvianus, Pseudupeneus grandisquamis, and Trachinotus kennedyi) were collected from Guerrero state during trawling operations. Additionally, As and Se levels in muscle tissue were compared with similar species from diverse areas. The order of As and Se concentrations was T. kennedyi>P. grandisquamis>D. peruvianus. In Mexico, there is no regulation of As and Se levels in fish. In comparison to the legal limit (0.1 µg g(-1) wet weight) set by legislation in Venezuela, As levels in the edible portion of T. kennedyi (0.632 µg g(-1) wet weight), P. grandisquamis (0.166 µg g(-1) wet weight), and D. peruvianus (0.157 µg g(-1) wet weight) were above this limit. In the case of Se, average concentrations in T. kennedyi (0.323 µg g(-1) wet weight) were above the maximum permissible limit (0.30 µg g(-1) wet weight) set in the Chilean legislation. Se concentrations in Carangoides bajad from Saudi Arabia were comparable to values in T. kennedyi (this study). In relation to As, concentrations varied in magnitude orders; the highest As concentration (range 10.35 to 23.71 µg g(-1) wet weight) corresponded to Mullus barbatus from the Iberian Mediterranean.


Subject(s)
Arsenic/metabolism , Crustacea/metabolism , Perciformes/metabolism , Selenium/metabolism , Water Pollutants, Chemical/metabolism , Animals , Arsenic/analysis , Environmental Monitoring , Fisheries , Mexico , Muscles/metabolism , Seafood/statistics & numerical data , Selenium/analysis
12.
Environ Monit Assess ; 187(7): 468, 2015 Jul.
Article in English | MEDLINE | ID: mdl-26116197

ABSTRACT

The aim of this study was to evaluate Fe and Mn distribution in geochemical fractions of the surface sediment of four oyster culture sites in the Sonora coast, Mexico. A selective fractionation scheme to obtain five fractions was adapted for the microwave system. Surface sediments were analyzed for carbonates, organic matter contents, and Fe and Mn in geochemical fractions. The bulk concentrations of Fe ranged from 10,506 to 21,918 mg/kg (dry weight, dry wt), and the bulk concentrations of Mn ranged from 185.1 to 315.9 mg/kg (dry wt) in sediments, which was low and considered as non-polluted in all of the sites. The fractionation study indicated that the major geochemical phases for the metals were the residual, as well as the Fe and Mn oxide fractions. The concentrations of metals in the geochemical fractions had the following order: residual >> Fe and Mn oxides > organic matter > carbonates > interchangeable. Most of the Fe and Mn were linked to the residual fraction. Among non-residual fractions, high percentages of Fe and Mn were linked to Fe and Mn oxides. The enrichment factors (EFs) for the two metals were similar in the four studied coasts, and the levels of Fe and Mn are interpreted as non-enrichment (EF < 1) because the metals concentrations were within the baseline concentrations. According to the environmental risk assessment codes, Fe and Mn posed no risk and low risk, respectively. Although the concentrations of Fe and Mn were linked to the residual fraction, the levels in non-residual fractions may significantly result in the transference of other metals, depending on several physico-chemical and biological factors.


Subject(s)
Aquaculture , Geologic Sediments/analysis , Iron/analysis , Manganese/analysis , Animals , California , Carbonates/analysis , Chemical Fractionation , Environmental Monitoring , Metals, Heavy/analysis , Mexico , Ostreidae , Oxides/analysis , Risk Assessment
13.
Environ Toxicol ; 27(9): 526-36, 2012 Sep.
Article in English | MEDLINE | ID: mdl-21374782

ABSTRACT

Mercury (Hg) transference through an established and defined food web from an urbanized subtropical coastal lagoon (SE Gulf of California) was examined by using carbon and nitrogen stable isotope and Hg analyses. Concentrations of Hg in seawater (0.045-0.078 µg L(-1)), predominantly incorporated to the particulate fraction (60% of total), were lower than those found in highly contaminated coastal areas around the world (0.18-16 µg L(-1)). Although levels of Hg available for the biota (e.g., associated to the reactive and pyrite fractions; 0.11-0.15 µg g(-1)) were within of effects range-low (ER-L, 0.15-0.71 µg g(-1)) these concentrations represented from 46.6 to 67.0% of the total Hg pool that may be transferred through food web. The sequence of bio-accumulation of Hg in studied species was according with their functional guild: tertiary consumer (0.85-1.15 µg g(-1)) > secondary consumers (0.084-0.168 µg g(-1)) > primary consumers (0.014-0.160 µg g(-1)) > primary producers (0.016-0.056 µg g(-1)). Hg concentrations increased for each successive trophic position estimate through δ(15) N isotopic values, although these relationships showed differences between dry and rainy seasons (R(2) = 0.37 and R(2) = 0.39 between δ(15) N vs. Hg in organisms, respectively). We concluded that Hg is being positively transferred (biomagnification factor >1) through the studied food web probably enhanced by the favorable environmental conditions for Hg-methylation (e.g., fine sediments rich in organic matter, and environmental conditions changes of the redox, pH, and temperature) found in this urbanized coastal water, however, the study of processes methlylation and biomagnifcation of Hg need further investigations.


Subject(s)
Food Chain , Mercury/analysis , Seasons , Water Pollutants, Chemical/analysis , Animals , Biota , California , Carbon Isotopes/analysis , Geologic Sediments/analysis , Nitrogen Isotopes/analysis , Seawater/analysis
14.
Environ Toxicol Chem ; 30(7): 1611-7, 2011 Jul.
Article in English | MEDLINE | ID: mdl-21442651

ABSTRACT

This investigation sought to assess the biological responses to Pb along a simplified four-level food chain, from the primary producer, the microalgae Tetraselmis suecica, grown in a control medium with < 1 µg/L of Pb and exposed to a sublethal dose (20 µg/L of Pb) and used as the base of a simulated food chain, through the primary-, secondary-, and tertiary-level consumers, namely, the brine shrimp, Artemia franciscana; the white-leg shrimp, Litopenaeus vannamei; and the grunt fish, Haemulon scudderi, respectively. Growth of Pb-exposed T. suecica was 40% lower than that of the control cultures, and survival of A. franciscana fed this diet was 25 to 30% lower than the control. No differences in the growth rates of Pb-exposed and control shrimp and fish and no gross morphological changes were evident in the exposed specimens. However, the exposed shrimp and fish had 20 and 15% higher mortalities than their controls, respectively. In addition, behavioral alterations were observed in exposed shrimp and fish, including reduction in food consumption or cessation of feeding, breathing air out of the water, reduction of motility, and erratic swimming. The negative correlation between Pb concentration in whole body of shrimp and fish and Fulton's condition factor suggested also that the exposed organisms were stressed because of Pb accumulation.


Subject(s)
Aquatic Organisms/drug effects , Food Chain , Lead/toxicity , Water Pollutants, Chemical/toxicity , Animals , Aquatic Organisms/metabolism , Artemia/drug effects , Artemia/metabolism , Diet , Lead/metabolism , Microalgae/drug effects , Microalgae/metabolism , Penaeidae/drug effects , Penaeidae/metabolism , Perciformes/metabolism , Stress, Physiological , Water Pollutants, Chemical/metabolism
15.
Environ Monit Assess ; 176(1-4): 109-23, 2011 May.
Article in English | MEDLINE | ID: mdl-20574698

ABSTRACT

The purpose of this study was to investigate the distribution of metals (Cd, Pb, Hg, Cu, Fe, Mn, and Zn) in dissolved and particulate fractions in seawater from Bacochibampo Bay, Northern part of Mexico. Water samples were collected from November 2004 to October 2005. Metal analysis was done by graphite furnace atomic absorption spectroscopy. Results indicated highest concentrations of dissolved Cd and Zn in the sites localized at the mouth and center of the bay. During summer and spring, the highest levels of Cd, Mn, and Fe were detected, Zn in fall, and Pb and Cu in winter and spring. Mercury was the only metal that was not found in this fraction. In particulate fraction, Fe, Hg, and Mn were the most abundant elements in all the sampling sites, followed by Zn, Cu, Pb, and Cd. The highest levels of the majority of the metals were observed in the coastline, suggesting a continental and/or urban source for these chemicals. The highest level of Cd was detected during the summer and the rest of the metals in the fall. Statistically significant correlations were observed between dissolved and particulate forms of Pb:Mn, Cu:Fe, and Cu:Mn. The mean partition coefficient values were as follows: Fe>Mn>Cu>Pb>Cd>Zn. All dissolved metal concentrations found, except Pb, were lower than EPA-recommended water quality values. The levels of dissolved metals in this study reveal low bioavailability and toxic potential. However, further toxicological and sediment chemistry studies in this area are needed for a full risk assessment.


Subject(s)
Environmental Monitoring/methods , Metals, Heavy/analysis , Seawater/analysis , Water Pollutants, Chemical/analysis , Cadmium/analysis , California , Copper/analysis , Iron/analysis , Lead/analysis , Manganese/analysis , Mercury/analysis , Zinc/analysis
16.
Bull Environ Contam Toxicol ; 80(2): 150-3, 2008 Feb.
Article in English | MEDLINE | ID: mdl-18196190

ABSTRACT

This work evaluates current metal concentrations (Cd, Cu, Pb and Zn) and the operational bio-available chemical extraction fraction in surface sediments in Mazatlán Harbor in Northwest México. Sediment samples were also analyzed for organic carbon, carbonates and particle size. Ranges of bulk metal were as follows: Cd from 3.1 to 3.3 microg/g, Cu from 31.9 to 44.9 microg/g, Pb from 49.6 to 54.0 microg/g, and Zn from 217.8 to 323.5 microg/g. In terms of biological effects, metals concentrations in the sediments lie between the low and median ranges of the mean quality guideline criteria. Comparatively, the metals concentrations increased from 1983 to 1994 and then for 2006, except Pb and Cd that decreased in the last period of time. The bio-available fraction of metals increased from 1983 to 1994, but only bio-available Cu increased from 1994 to 2006, due to mobilization of this metal from the organic matter-sulfide phase.


Subject(s)
Geologic Sediments/chemistry , Metals, Heavy/analysis , Water Pollutants, Chemical/analysis , Cadmium/analysis , Copper/analysis , Lead/analysis , Zinc/analysis
17.
Food Chem Toxicol ; 45(9): 1599-605, 2007 Sep.
Article in English | MEDLINE | ID: mdl-17418927

ABSTRACT

This study investigates the presence of Cu, Zn, Cd, Pb, and Hg in 24 dietary supplements purchased in different health stores across the city of Hermosillo, located in the northwest of Mexico. Analysis of metals was done by microwave digestion and atomic absorption spectroscopy. The most abundant elements in dietary supplements were Cu (<0.19-137.85 microg/g) and Zn (<2.83-4785.71 microg/g), followed by Pb (<0.003-66.32 microg/g), Cd (<0.001-2.90 microg/g), and Hg (<0.24-0.85 microg/g). The estimated daily intakes of metals were below those recommended by WHO and the Institute of Medicine, showing that little risk from heavy metals is associated with the consumption of the dietary supplements analyzed. However, some products presented more than 10% of the tolerable daily intake of Pb, indicating that production processes should be improved.


Subject(s)
Consumer Product Safety , Dietary Supplements/analysis , Food Contamination/analysis , Metals, Heavy/administration & dosage , Metals, Heavy/analysis , Cadmium/administration & dosage , Cadmium/analysis , Copper/administration & dosage , Copper/analysis , Humans , Lead/administration & dosage , Lead/analysis , Mercury/administration & dosage , Mercury/analysis , Mexico , Risk Factors , Spectrophotometry, Atomic/methods , Zinc/administration & dosage , Zinc/analysis
19.
Mar Pollut Bull ; 50(7): 733-9, 2005 Jul.
Article in English | MEDLINE | ID: mdl-15993140

ABSTRACT

In early April 2003, fishermen from Kino Bay Sonora alerted us about a massive die-off of fish and mollusks occurring at Kun Kaak Bay. Phytoplankton samples taken on 17 May 2003 reported the presence of a harmful algal bloom composed of Chatonella marina, Chatonella cf. ovata, Gymnodinium catenatum and Gymnodinium sanguineum. On 22 of May, we collected samples of water, sediment and organisms at the affected area. Physicochemical parameters and nutrients were measured in water samples from different depths. Sediment and benthic organisms were analyzed for Cd, Cu, Zn, Pb and Hg. We found concentrations of heavy metals higher than background levels for this area. Cadmium and Lead concentrations in sediment from the HAB area were up to 6x greater than background levels and Cd in mollusks was 8x greater than regulations allow. A relationship between elevated Cd and Pb concentrations in sediment and the survival of toxic dinoflagellates is suspected.


Subject(s)
Eukaryota , Geologic Sediments/chemistry , Metals, Heavy/analysis , Mollusca/chemistry , Water Pollutants, Chemical/analysis , Animals , Environmental Monitoring , Metals, Heavy/toxicity , Mexico , Mollusca/metabolism , Oceans and Seas , Water Pollutants, Chemical/toxicity
20.
Arch. latinoam. nutr ; 50(1): 26-34, mar. 2000. tab, graf
Article in Spanish | LILACS | ID: lil-283295

ABSTRACT

En la producción de fórmulas hipoalergénicas, bebidas fortificadas y nutracéuticos para alimentación especial, se requieren ingredientes ideales. En este estudio, se obtuvieron ingredientes proteicos por medio de hidrólisis y síntesis enzimática con metionina a la proteína de soya. La hidrólisis se realizó al 4 por ciento (p/v) con enzimas pancreáticas porcinas al 4 por ciento (p/p), 50ºC, 6h y pH 8. El hidrolizado seco se resuspendió al 20 por ciento (p/v) e incubó con 7,6 por ciento de metiléster de metionina (p/p), quimotripsina al 1 por ciento (p/p) y glicerol 3 M, 37ºC, 3 h y pH 7.0. Ates y después del enriquecimiento (E), el hidrolizado se fraccionó en 3 partes por ultrafiltración (UF): FI>10, 10>FII>3 y 3>FIII>1 kDa. A la proteína nativa y todas las fracciones se les evaluaron propiedades funcionales, aminoácidos, factores antifisiológicos y antigenicidad; así como la calidad proteica y características sensoriales a 2 de ellas. La hidrólisis y síntesis modificaron las propiedades proteicas y el enriquecimiento se dio en un mínimo de tiempo y metionina añadida. Después de la UF, las fracciones menores de 10 kDa presentaron solubilidad completa (pH 4 y 7), buena claridad y regular capacidad espumante. La FIII-E por su calidad nutricia, nulas antigenicidad y actividad antifisiológica, puede utilizarse en fórmulas infantiles hipoalergénicas. La FII-E por su composición de aminóacidos es adecuada para formúlas fortificadas solubles y como única proteína en nutracéuticos. La FI, semejante al aislado comercial, es utilizable amortizando costos. La FI-E por su contenido de metionina, la estabilidad de su espuma, su actividad emulsificante y buen sabor, puede utilizarse en papillas infantiles


Subject(s)
Food Analysis/classification , Feeding Behavior , Soybean Proteins/administration & dosage , Mexico , Nutritional Sciences
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