scholarly journals Monitoring of Environmental Hg Occurrence in Tunisian Coastal Areas

Author(s):  
Amel Jebara ◽  
Vincenzo Lo Turco ◽  
Caterina Faggio ◽  
Patrizia Licata ◽  
Vincenzo Nava ◽  
...  

Total mercury (Hg) was determined in 450 environmental samples (seawater, sediment plant and fish) from five Mahdia coastal areas (Tunisia). Tolerable Weekly Intake% (TWI) values, according to the European Food Safety Authority (EFSA), were calculated based on the average metal concentration in fish and the average weekly fish consumption rate. Hg was accumulated mainly in fish and in Posidonia oceanica leaves. Hg in sediment ranged from 1.88 μg/kg dry weight (d.w.) to 7.48 μg/kg d.w., while it was between 0.32 μg/kg and 0.19 μg/kg in seawaters. Our study showed high concentration in Posidonia oceanica in S3 (plant = 16.76 ± 4.48 μg/kg d.w.) as compared to those in S4 sites (plant = 5.33 ± 0.05 μg/kg d.w.). Concentrations for S. aurata and S. salpa in the Rejiche area exceeded the EC 1881/2006 legislation with values of 1.9 mg/kg and 2.5 mg/kg, respectively, and consumers may be exposed to high concentrations of Hg that exceeds the EFSA. The results showed that the fish species should be constantly monitored due to their TWI% of 154.5% for S. aurata and 209.8% S. salpa respectively.

Biologia ◽  
2013 ◽  
Vol 68 (5) ◽  
Author(s):  
Abdulali Taweel ◽  
Mohammad Shuhaimi-Othman ◽  
Abas Ahmad

AbstractIn recent years, many studies have stated the nutritional benefits of fish consumption: vitamins, proteins and omega-3 fatty acids, which may protect humans from adverse health effects, including heart disease and stroke. This study aimed to evaluate the concentration of Cu, Pb and As in the liver, gills and muscles of tilapia fish (Oreochromis niloticus) and to calculate the weekly intake from eating tilapia collected from Cempaka Lake, Selangor — Peninsular Malaysia during the period between April 2009 to February 2010. The elemental concentrations were determined using inductively — coupled plasma mass spectrometry (ICP-MS). The results showed that all heavy metal concentrations were significantly different among fish organs, and between calendar months. The data showed that Cu levels in liver, gills and muscles were 491.30, 3.70 and 1.82 μg/g dry weight (dw), respectively. Meanwhile Pb levels were 2.71, 1.04 and 0.48 μg/g dw, respectively and As levels were 6.26, 4.18 and 1.79 μg/g dw, respectively. Significant changes occurred in Cu, Pb and As levels in tilapia fish organs in Cempaka Lake over the period of 11 months. Tilapia weekly intake was calculated based on mean Cu, Pb and As concentrations in the muscle of tilapia fish and adult consumption of tilapia in Malaysia which averages at 160 grams per day. Furthermore, tilapia weekly and daily human intakes for Cu, Pb and As were compared with the Provisional Tolerable Weekly Intake (PTWI) established by the JECFA (WHO/FAO) presenting values below the PTWI. Metal levels in fish muscle were found to be lower than the maximum permitted concentrations recommended by various authorities; hence, consumption of tilapia fish from Cempaka Lake is currently safe for humans.


Toxins ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 249 ◽  
Author(s):  
Liliana J. G. Silva ◽  
Ana C. Teixeira ◽  
André M. P. T. Pereira ◽  
Angelina Pena ◽  
Celeste M. Lino

Ochratoxin A (OTA) is produced by fungi present in several agricultural products with much relevance to food safety. Since this mycotoxin is widely found in cereals, beer has a potential contamination risk. Therefore, it was deemed essential to quantify, for the first time, the levels of OTA in beer, a cereal-based product that is marketed in Portugal, as well as to calculate the human estimated weekly intake (EWI) and risk assessment. A total of 85 samples were analyzed through immunoaffinity clean-up, followed by liquid chromatography-fluorescence detection (LC-FD). This analytical methodology allowed a limit of quantification (LOQ) of 0.43 µg/L. The results showed that 10.6% were contaminated at levels ranging between <LOQ and 11.25 µg/L, with an average of 3.14 ± 4.09 µg/L. Samples of industrial production presented lower incidence and contamination levels than homemade and craft beers. On what concerns human risk, the calculated EWI was significantly lower than the tolerable weekly intake (TWI). However, in the worst case scenario, based on a high concentration, the rate EWI/TWI was 138.01%.


2019 ◽  
Author(s):  
Alvaro Ferreira Monteiro ◽  
Ingrid Santos Miguez ◽  
João Pedro R. Barros Silva ◽  
Ayla Santana Silva

AbstractThe açaí berry’s seed corresponds to 85–95% of the fruit’s weight and represents ~1.1 million tons of residue yearly accumulated in the Amazon region. This study confirmed that mannan is the major component of mature seeds, corresponding to 80% of the seed’s total carbohydrates and about 50% of its dry weight. To convert this high mannan content into mannose, a sequential process of diluted acid and enzymatic hydrolysis was evaluated. Diluted-H2SO4 hydrolysis (3%-acid, 60-min, 121°C) resulted in a 30% mannan hydrolysis yield and 41.7 g/L of mannose. Because ~70% mannan remained in the seed, a mannanase-catalyzed hydrolysis was sequentially performed with 2–20% seed concentration, reaching 146.3 g/L of mannose and a 96.8% yield with 20% solids. As far as we know, this is the highest reported concentration of mannose produced from a residue. Thus, this work provides fundamental data for achieving high concentrations and yields of mannose from açaí seeds.HighlightsMannan was confirmed as the major component (~50%) of açaí seeds.Diluted-H2SO4 hydrolysis had a limited effect on mannan conversion into mannose.Enzymatic hydrolysis was sequentially performed with a high seed concentration.Mannan was efficiently hydrolyzed by mannanases, producing a 96.8% yield.Mannose production of 146.3 g/L was obtained with mannanase-catalyzed hydrolysis.Graphical abstract


2001 ◽  
Vol 84 (6) ◽  
pp. 1964-1971 ◽  
Author(s):  
Maja Blanuša ◽  
Antun Kučak ◽  
Veda-Marija Varnai ◽  
Marijana Matek Sarić

Abstract The concentration of trace elements (Cd, Cu, Fe, Mn, and Zn) was measured in different species of mushrooms (Boletaceae) and correlated with corresponding elements in soil. Five different species of Boletaceae mushrooms and soil samples were collected from forests of Varaždin county in Croatia. Trace elements were analyzed by atomic absorption spectrometry in mushrooms and in EDTA-extracted soil. The results showed that Cd, Cu, and Zn are concentrated in mushroom tissue from soil with transfer factors (mushroom/soil) of 27.0, 10.5, and 12.5, respectively. Cadmium incorporated much less in Leccinum (mean 0.73 mg/kg dry weight) than in Boletus, Xerocomus, or Gyroporus (respective means, 6.8, 8.4, and 12.3 mg/kg). Copper and Zn were accumulated in all collected mushrooms (14.7–35.6 and 109–179 mg/kg, respectively) with no difference among species. There was no accumulation of Fe and Mn in mushrooms, but concentrations differed between species, with lowest values in Leccinum. Iron varied from 31 to 878 mg/kg and Mn from 2.9 to 409 mg/kg. Correlations between elements in mushrooms and soil were significant only for Mn. Because no significant correlations for Cd, Cu, Zn, and Fe between mushrooms and soil were found, more studies are needed with only one species of mushrooms collected at locations with different levels of soil contamination. In spite of higher concentrations of Cd in some Boletaceae species, it is assumed that Cd intake through moderate mushroom consumption remains below suggested Provisional Tolerable Weekly Intake (FAO/WHO).


2009 ◽  
Vol 12 (12) ◽  
pp. 2352-2358 ◽  
Author(s):  
Kozue Yaginuma-Sakurai ◽  
Miyuki Shimada ◽  
Takashi Ohba ◽  
Kunihiko Nakai ◽  
Keita Suzuki ◽  
...  

AbstractObjectiveTo examine whether an FFQ can be used for assessing exposure to methylmercury (MeHg) by estimating MeHg intake from seafood consumption using the FFQ and confirming the accuracy of the estimated value.DesignSeafood consumption of pregnant women was assessed using the FFQ. Total mercury (T-Hg) concentrations of maternal red blood cells (RBC) and hair were measured as exposure indices of MeHg.SettingA prospective birth cohort study, the Tohoku Study of Child Development (TSCD), which has been ongoing since 2001.SubjectsThe subjects were 609 pregnant Japanese women who were enrolled in the TSCD.ResultsMeHg intake was estimated from seafood consumption determined using the FFQ and the MeHg concentrations in each type of seafood. The accuracy of the estimated value was confirmed by comparison with T-Hg in RBC and hair. Estimated MeHg intake was 42·3 μg/week, and 43·0 % of that was from large predatory fish. Compared with the Japanese tolerable weekly intake, in total 12·5 % of the subjects exceeded it. T-Hg concentrations in RBC and hair were significantly correlated with estimated MeHg intake: r = 0·325 (P < 0·0001) for RBC and r = 0·305 (P < 0·0001) for hair.ConclusionsEstimated MeHg intake based on the FFQ was significantly associated with T-Hg concentrations in RBC and hair. Although the estimated value involves uncertainties, the FFQ appears to be a useful tool for assessment of exposure to MeHg.


1965 ◽  
Vol 97 (1) ◽  
pp. 104-111 ◽  
Author(s):  
EA Bell ◽  
ASL Tirimanna

1. The genus Vicia may be subdivided into groups of species characterized by associations of ninhydrin-positive compounds occurring in high concentrations in their seeds. Despite these subdivisions the overall distribution pattern emphasizes the unity of the genus and the possible value of such studies in establishing degrees of relationship between species within the genus. 2. Canavanine is a major constituent in the seeds of 17 species. 3. gamma-Hydroxyarginine, an amino acid that has not been found in other plant genera, occurs in 18 species. 4. gamma-Hydroxyornithine, a new natural amino acid, is found in two species. 5. A new naturally occurring ureido amino acid tentatively identified as; gamma-hydroxycitrulline' is found in two species. 6. High concentrations of alphabeta-diaminopropionic acid are found in seed of V. baicalensis and of alphagamma-diaminobutyric acid in seed of V. aurantica. 7. The neurotoxic amino acid beta-cyanoalanine and its gamma-glutamyl peptide are found together in high concentrations in the seeds of 16 species of this agriculturally important genus. 8. Seven unidentified ninhydrin-positive compounds occur in high concentration (about 1% of the dry weight or more) in the seed of various species. Details of their R(F) values, ionic mobilities and colour reactions are given. 9. The total concentration of extractable ninhydrin-positive compounds varies little between seeds of different species and these compounds may, as has been suggested for those in Lathyrus, constitute a readily available form of storage nitrogen. 10. The nature and distribution, as opposed to the total concentration, of the amino acids and related compounds accumulated in the seeds of Vicia are different from those accumulated in the seeds of the related genus, Lathyrus. One particularly interesting difference is the accumulation of C(6) guanidino amino acids (arginine and gamma-hydroxyarginine) by Vicia and the accumulation of C(7) guanidino amino acids (homoarginine, gamma-hydroxyhomoarginine and the related amino acid lathyrine) by Lathyrus. Such differences afford a method for distinguishing between species of these genera.


Author(s):  
Nael Mohammed Sarheed ◽  
Osamah Faisal Kokas ◽  
Doaa Abd Alabas Muhammed Ridh

The plant of castor is widely spread in the Iraqi land, and characterized with containing ricin toxin, which has a very serious effects, and because the seeds of this plant scattered in the agricultural soil and rivers water, which increases the exposure of humans and animals to these beans. Objective: This experiment was designed to study the effect of high concentration of castor bean powder in some physiological and biochemical parameters and changes in some tissues of the body, as well as trying to use doxycycline to reduce the effects of ingestion of these seeds. Materials and Methods: In the experiment, 24 local rabbits were raised and fed in the Animal House of the Faculty of Medicine / Al-Muthanna University, then divided into four groups and treated for three weeks (21 days), Control group: treated with normal saline solution (0.9) orally throughout the experiment, G1: was treated orally with a concentration of 25 mg / kg of castor bean powder daily during the experiment, G2 : orally treated 25 mg / kg of castor bean and 25 mg / kg of doxycycline, G3: orally treated 25 mg / kg of castor powder with 50 mg / kg of doxycycline daily throughout the trial period. Results: The results of the experiment showed significant changes (P less than 0.05) in all physiological and biochemical blood tests when compared with control group. There was a significant decrease in PCV, Hb, RBC, T.protein and body weights, while demonstrated a significant increase in WBC, Urea, Creatinine, ALT, AST and ALP, with distortions in liver and kidney of animals that treated with Castor beans. In contrast, the treatment with doxycycline and caster beans showed significant improvement reflected by a normal proportion in physiological tests and biochemical tests with improvement in the tissues when compared to control group. Conclusions: It can be concluded from this study that castor bean has high toxic and pathogenic effects that may be dangerous to the life of the organism. Therefore, it is advisable to be cautious of these pills and avoid exposure to them, also recommended to take high concentrations of doxycycline treatment when infected with castor bean poisoning.


2020 ◽  
Vol 65 (9-10) ◽  
pp. 3-7
Author(s):  
V. V. Gostev ◽  
Yu. V. Sopova ◽  
O. S. Kalinogorskaya ◽  
M. E. Velizhanina ◽  
I. V. Lazareva ◽  
...  

Glycopeptides are the basis of the treatment of infections caused by MRSA (Methicillin-Resistant Staphylococcus aureus). Previously, it was demonstrated that antibiotic tolerant phenotypes are formed during selection of resistance under the influence of high concentrations of antibiotics. The present study uses a similar in vitro selection model with vancomycin. Clinical isolates of MRSA belonging to genetic lines ST8 and ST239, as well as the MSSA (ATCC29213) strain, were included in the experiment. Test isolates were incubated for five hours in a medium with a high concentration of vancomycin (50 μg/ml). Test cultures were grown on the medium without antibiotic for 18 hours after each exposure. A total of ten exposure cycles were performed. Vancomycin was characterized by bacteriostatic action; the proportion of surviving cells after exposure was 70–100%. After selection, there was a slight increase in the MIC to vancomycin (MIC 2 μg/ml), teicoplanin (MIC 1.5–3 μg/ml) and daptomycin (MIC 0.25–2 μg/ml). According to the results of PAP analysis, all strains showed an increase in the area under curve depending on the concentration of vancomycin after selection, while a heteroresistant phenotype (with PAP/AUC 0.9) was detected in three isolates. All isolates showed walK mutations (T188S, D235N, E261V, V380I, and G223D). Exposure to short-term shock concentrations of vancomycin promotes the formation of heteroresistance in both MRSA and MSSA. Formation of VISA phenotypes is possible during therapy with vancomycin.


1996 ◽  
Vol 31 (3) ◽  
pp. 485-504 ◽  
Author(s):  
Patricia Chow-Fraser ◽  
Barb Crosbie ◽  
Douglas Bryant ◽  
Brian McCarry

Abstract During the summer of 1994, we compared the physical and nutrient characteristics of the three main tributaries of Cootes Paradise: Spencer, Chedoke and Borer’s creeks. On all sampling occasions, concentrations of CHL α and nutrients were always lowest in Borer’s Creek and highest in Chedoke Creek. There were generally 10-fold higher CHL α concentrations and 2 to 10 times higher levels of nitrogen and phosphorus in Chedoke Creek compared with Spencer Creek. Despite this, the light environment did not differ significantly between Spencer and Chedoke creeks because the low algal biomass in Spencer Creek was balanced by a relatively high loading of inorganic sediments from the watershed. Laboratory experiments indicated that sediments from Chedoke Creek released up to 10 µg/g of soluble phosphorus per gram (dry weight) of sediment, compared with only 2 µg/g from Spencer Creek. By contrast, sediment samples from Spencer Creek contained levels of polycyclic aromatic hydrocarbon that were as high as or higher than those from Chedoke Creek, and much higher than those found in Borer’s Creek. The distribution of normalized PAH concentrations suggests a common source of PAHs in all three tributaries, most likely automobile exhaust, since there were high concentrations of fluoranthene and pyrene, both of which are derivatives of engine combustion.


1997 ◽  
Vol 35 (2-3) ◽  
pp. 339-345 ◽  
Author(s):  
M. G. Dubé ◽  
J. M. Culp

Experiments were conducted in artificial streams to determine the effects of increasing concentrations of biologically treated bleached kraft pulp mill effluent (BKPME) on periphyton and chironomid growth in the Thompson River, British Columbia. Periphyton growth, as determined by increases in chlorophyll a, was significantly stimulated at all effluent concentrations tested (0.25%, 0.5%, 1.0%, 5.0% and, 10.0%). Chironomid growth (individual weight) was also significantly stimulated at low effluent concentrations (≤1.0%). At higher concentrations (5.0% and 10.0%), chironomid growth was inhibited relative to the 1.0% treatment streams. Increases in growth were attributed to the effects of nutrient and organic enrichment from BKPME. The effluent contained high concentrations of phosphorus and appears to be an important source of carbon for benthic insects grazing on the biofilm. In high concentration effluent streams, chironomid growth decreased despite low levels of typical pulp mill contaminants. This suggests that other compounds in the effluent, such as wood extractives, may be inhibiting chironomid growth. These results support findings of field monitoring studies conducted in the Thompson River where changes in periphyton and chironomid abundance occurred downstream of the bleached kraft pulp mill.


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