Heavy Metal Concentrations in the Muscle Tissue of 12 Species of Teleost from Cockburn Sound, Western Australia

1979 ◽  
Vol 30 (5) ◽  
pp. 607 ◽  
Author(s):  
D Plaskett ◽  
IC Potter

The wet and dry weight concentrations of Cd, Zn, Cu, Pb, Fe, Mn, Ni, Cr and Co have been measured in muscle tissue taken from 12 species of teleost caught in Cockburn Sound. The maximum concentration of each of the metals found in the fish was well below the values given in the National Health and Medical Research Council Standards and the Western Australian Food and Drug Regulations. Considering the rate at which metals are known to be discharged into the Sound the low concentrations found in fish flesh contrast with the appreciable rate at which metals are discharged and accumulate in certain regions of the Sound. Furthermore, the metal concentrations in fish flesh are many times lower than in invertebrates such as the mussel, Mytilus edulis. It is suggested that the low levels in fish flesh reflect both the relatively low rate at which heavy metals are accumulated by teleost muscle and also the movement pattern of fish within the polluted and relatively unpolluted regions of the Sound, and between the Sound and the Indian Ocean.

2013 ◽  
Vol 40 (9) ◽  
pp. 931 ◽  
Author(s):  
Thiago Couto ◽  
Bernardo Duarte ◽  
Dimitri Barroso ◽  
Isabel Caçador ◽  
João C. Marques

Heavy metal concentrations present in the above- and beowground tissues of Scirpus maritimus L., Spartina maritima (Curtis) Fernald and Zostera noltii Hornem were analysed seasonally in the Mondego Estuary, Portugal. The sediments of the estuary were confirmed to contain only low concentrations of heavy metals. The belowground tissues of all three species showed higher heavy metal concentrations than the aboveground tissues. Although the sediments only contained low levels of contamination, because the area occupied by S. maritimus and Z. noltii was large, significant quantities of heavy metals were accumulated and exported to the surrounding water bodies. In contrast with observations of highly contaminated estuaries, it was found that in spite of the low level of contaminants in the sediments of the Mondego Estuary, aquatic vegetation functioned as a source of metals for nearby systems.


2000 ◽  
Vol 125 (3) ◽  
pp. 294-298 ◽  
Author(s):  
Daniel J. Barta ◽  
Theodore W. Tibbitts

Tissue concentrations of Ca, Mg, and K were determined across immature leaves of lettuce (Lactuca sativa L. `Buttercrunch') at different stages of enlargement using electron microprobe x-ray analysis. The analysis was with a wavelength dispersive spectrometer to permit detection of low concentrations of Ca. Patterns of mineral accumulation in immature leaves that were exposed were compared to patterns of accumulation in leaves that were enclosed within a developing head. The leaves developing without enclosure were free to transpire and developed normally whereas leaves developing with enclosure were restricted in transpiration and developed an injury that was characteristic of Ca deficiency. In the exposed leaves, Ca concentrations increased from an average of 1.0 to 2.1 mg·g-1 dry weight (DW) as the leaves enlarged from 5 to 30 mm in length. In the enclosed leaves, Ca concentrations decreased from 1.0 to 0.7 mg·g-1 DW as the leaves enlarged from 5 to 30 mm in length. At the tips of these enclosed leaves a larger decrease was found, from 0.9 to 0.3 mg·g-1 DW during enlargement. Necrotic injury first became apparent in this tip area when the concentration was ≈0.4 mg·g-1 DW. Magnesium concentrations across the exposed leaves were similar to concentrations across the enclosed leaves, and did not change with enlargement. Magnesium concentrations averaged 3.5. mg·g-1 DW in both enclosed and exposed leaves during enlargement from 5 to 30 mm. In both exposed and enclosed leaves, K concentrations increased during enlargement from 40 to ≈60 mg·g-1 DW. Potassium concentrations were highest toward the leaf apex and upper margin where injury symptoms occurred, and this may have enhanced injury development. This research documents the critical low levels of Ca (0.2 to 0.4 mg·g-1 DW) that can occur in enclosed leaves of plants and which apparently leads to the marginal apex necrosis of developing leaves seen frequently on lettuce and other crops.


2003 ◽  
Vol 3 (5-6) ◽  
pp. 303-310 ◽  
Author(s):  
S.-H. Yi ◽  
S. Ahmed ◽  
Y. Watanabe ◽  
K. Watari

Conventional arsenic removal processes have difficulty removing low concentrations of arsenic ion from water. Therefore, it is very hard to comply with stringent low levels of arsenic, such as below 10 μg/L. So, we have developed two arsenic removal processes which are able to comply with more stringent arsenic regulations. They are the MF membrane process combined with chemical sludge adsorption and NF membrane process equipped with the vibratory shear enhanced process (VSEP). In this paper, we examine the performance of these new processes for the removal of arsenic ion of a low concentration from water. We found that chemical sludge produced in the conventional rapid sand filtration plants can effectively remove As (V) ions of H2AsO4- and HAsO42- through anion exchange reaction. The removal efficiency of MF membrane process combined with chemical sludge adsorption increased to about 36%, compared to MF membrane alone. The strong shear force on the NF membrane surface produced by vibration on the VSEP causes the concentration polarization layer to thin through increased back transport velocity of particles. So, it can remove even dissolved constituents effectively. Therefore, As (V) ions such as H2AsO4- and HAsO42- can be removed. The concentration of As (V) ions decreased from 50 μg/L to below 10 μg/L and condensation factor in recirculating water increased up to 7 times by using NF membrane equipped with VSEP.


Toxins ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 232
Author(s):  
Antonio Gallo ◽  
Francesca Ghilardelli ◽  
Alberto Stanislao Atzori ◽  
Severino Zara ◽  
Barbara Novak ◽  
...  

Sixty-four corn silages were characterized for chemicals, bacterial community, and concentrations of several fungal metabolites. Silages were grouped in five clusters, based on detected mycotoxins, and they were characterized for being contaminated by (1) low levels of Aspergillus- and Penicillium-mycotoxins; (2) low levels of fumonisins and other Fusarium-mycotoxins; (3) high levels of Aspergillus-mycotoxins; (4) high levels of non-regulated Fusarium-mycotoxins; (5) high levels of fumonisins and their metabolites. Altersetin was detected in clusters 1, 3, and 5. Rugulusovin or brevianamide F were detected in several samples, with the highest concentration in cluster 3. Emodin was detected in more than 50.0% of samples of clusters 1, 3 and 5, respectively. Kojic acid occurred mainly in clusters 1 and 2 at very low concentrations. Regarding Fusarium mycotoxins, high occurrences were observed for FB3, FB4, FA1, whereas the average concentrations of FB6 and FA2 were lower than 12.4 µg/kg dry matter. Emerging Fusarium-produced mycotoxins, such as siccanol, moniliformin, equisetin, epiequisetin and bikaverin were detected in the majority of analyzed corn silages. Pestalotin, oxaline, phenopirrozin and questiomycin A were detected at high incidences. Concluding, this work highlighted that corn silages could be contaminated by a high number of regulated and emerging mycotoxins.


Author(s):  
Elisa Serviere-Zaragoza ◽  
Salvador E. Lluch-Cota ◽  
Alejandra Mazariegos-Villarreal ◽  
Eduardo F. Balart ◽  
Hugo Valencia-Valdez ◽  
...  

In the Gulf of California; mineral deposits have contributed to high metal contents in coastal environments. This study examined cadmium; lead; copper; zinc; and iron contents in three fish species; Kyphosus vaigiensis (herbivore), Stegastes rectifraenum (omnivore), and Balistes polylepis (carnivore) at two mining sites. Metal concentrations were analyzed by atomic absorption spectrophotometry and stable nitrogen and carbon isotopes were estimated using mass spectrophotometry. Also, we assessed the risk to human health from the consumption of these three species based on permissible limits; although only two of them (Kyphosus and Balistes) are consumed as food. Metal concentrations differed among fish species; except for iron. The highest concentrations of metals were not always recorded in the species at the highest trophic level; i.e., Balistes. The highest concentrations (dry weight) recorded were cadmium (0.21 ± 0.03 µg g−1) and lead (1.67 ± 0.26 µg g−1), in S. rectifraenum; copper (1.60 ± 0.49 µg g−1) and zinc (67.30 ± 8.79 µg g−1), in B. polylepis; and iron (27.06 ± 2.58 µg g−1), in K. vaigiensis. Our findings show that each element accumulates differently in particular marine organisms; depending on the physiology of the species and the biogeochemistry of its habitat; which in turn is affected by the anthropogenic activities in adjacent areas. No risk of heavy metals toxicity is expected from the human consumption of the species and sites studied


2001 ◽  
Vol 13 (3) ◽  
pp. 271-279 ◽  
Author(s):  
Brent J. Sinclair ◽  
Heidi Sjursen

Cold tolerance of the springtail Gomphiocephalus hodgsoni Carpenter (Collembola: Hypogastruridae) was studied at Cape Bird, Ross Island, Antarctica (77°13′S, 166°26′E). Microclimate temperatures indicate a highly seasonal thermal environment, with winter minima <–39°C. Snow cover significantly buffers both minimum temperatures and cooling rates. Gomphiocephalus hodgsoni survives low temperatures by avoiding freezing. Mean low group supercooling points (SCPs) ranged from –35.4°C in October to –28.3°C in January. The lowest SCP measured was –38.0°C. The high SCP group was very small, making up only 18% of the population in January. In October, G. hodgsoni had a very high glycerol content (>80 μg mg−1 dry weight), although this declined rapidly to low levels (c. 7–10 μg mg−1 dry weight) in January. Quantities of glucose and trehalose were low during October, but steadily increased throughout the summer. Haemolymph osmolality was exceptionally high (up to 1755 mOsm kg−1) at the end of November, but this rapidly declined to c. 500 mOsm kg−1 by late December. The presence of thermal hystersis proteins was indicated by both osmometry on haemolymph samples and recrystallization inhibition studies of springtail homogenates. There was a strong relationship between glycerol content and SCP, but the relationship between haemolymph osmolality, SCP and carbohydrates is uncertain.


1950 ◽  
Vol 26 (4) ◽  
pp. 396-409
Author(s):  
LORD ROTHSCHILD

1. Spermatozoa and seminal plasma of Echinus esculentus contain catalase. 2. At 15° C., 4 ml. of a suspension of semen diluted with neutral phosphate buffer in the ratio 1:13 produced in 1 min. 90µl. O2 from an H2O2 solution containing 150 µl. O2. The dry weight of semen in the suspension was 45 mg. and the number of spermatozoa 8.55x109. Under the same conditions, seminal plasma obtained by centrifuging semen produced 50 µl. O2 in 1 min. The dry weight of seminal plasma in the suspension was 12 mg. Human blood, dry weight 229.3 mg./ml., must be diluted with phosphate buffer in the ratio 1:1700 to produce the same amount of O2 in 1 min. as the above suspension of semen. If catalatic activity is defined by the equation Ac = (gt)-1 In {a/(a-x)}, where g = weight in g./ml. of the catalase-containing material, t = 1 min., a = initial substrate concentration (H2O2), and x = amount of H2O2 decomposed in 1 min. at 15° C., Ac = 80-100, 150-200 and 6800 respectively for sea-urchin semen, sea-urchin seminal plasma and human blood. 3. The catalatic activity of semen and seminal plasma is strongly inhibited by hydroxylamine. 4. The O2 uptake and motility of sea-urchin spermatozoa is unaffected by M/5000 H2O2. Higher concentrations of H2O2, M/3000-5000, produce a pronounced ‘shock’ effect, from which the spermatozoa often completely recover. 5. Low concentrations of hydroxylamine, M/3000, reduce O2 uptake and motility. 6. Sea-urchin spermatozoa are almost instantly killed by combinations of hydroxylamine and H2O2, at concentrations which are relatively innocuous when the substances are added separately. 7. A rough calculation indicates that a single spermatozoon contains less than 500 molecules of catalase. 8. A new method of adding H2O2 to catalase-containing material in a manometer is described.


2004 ◽  
Vol 47 (2) ◽  
pp. 319-327 ◽  
Author(s):  
Alexandre Gomes Ferreira ◽  
André Luís dos Santos Machado ◽  
Ilana Rosental Zalmon

Heavy metal (Cd, Cr, Cu, Fe, Mn, Ni, Pb and Zn) concentrations were studied in Perna perna from three beaches (Barra do Furado, Buena and Ponta do Retiro) on the northern coast of Rio de Janeiro State by ICP-AES. The average concentration was 0.3 ± 0.04 (Cd); 1.9 ± 0.6 (Cr); 6.1 ± 0.7 (Cu); 1,130 ± 113 (Fe); 22 ± 3.2 (Mn); 9.3 ± 4.6 (Ni); 0.4 ± 0.2 (Pb); 44 ± 5.8 (Zn) µg.g-1 dry weight. There were no significant difference for almost all the studied metals in relation to sex. Although, significant spatial variations (p < 0.05) occurred for Cr, Pb and Ni with higher values for Barra do Furado. Temporal variations were significant (p < 0.05) at the three beaches, however, no trends of accumulation were observed. The metal concentrations were similar to areas under low pollution impact, except for Fe, which was probably due to the local substrates enriched in iron oxides.


2011 ◽  
Vol 61 (11) ◽  
pp. 2626-2631 ◽  
Author(s):  
K. S. Inglett ◽  
H. S. Bae ◽  
H. C. Aldrich ◽  
K. Hatfield ◽  
A. V. Ogram

A Cr(VI)-resistant, Gram-positive, spore-forming, obligate anaerobe, designated GCAF-1T, was isolated from chromium-contaminated soil by its ability to reduce Cr(VI) in low concentrations. Mixed acid fermentation during growth on glucose resulted in accumulation of acetate, butyrate, formate and lactate. Morphological studies indicated the presence of peritrichous flagella, pili and an S-layer. The major cellular fatty acids (>5 %) were C16 : 0, C14 : 0, summed feature 3 (comprising iso-C15 : 0 2-OH and/or C16 : 1ω7c), C18 : 1ω7c, C16 : 1ω9c, summed feature 4 (comprising iso-C17 : 1 I and/or anteiso-C17 : 1 B) and C18 : 1ω9c. The DNA G+C content of strain GCAF-1T was 30.7 mol%. Phylogenetic interference indicated that strain GCAF-1T clustered with group I of the genus Clostridium. Of strains within this cluster, strain GCAF-1T shared the highest 16S rRNA gene sequence similarities (98.1–98.9 %) with Clostridium beijerinckii DSM 791T, C. saccharobutylicum NCP 262T, C. saccharoperbutylacetonicum N1-4T, C. puniceum DSM 2619T and C. roseum DSM 51T. However, strain GCAF-1T could be clearly distinguished from its closest phylogenetic neighbours by low levels of DNA–DNA relatedness (<50 %) and some phenotypic features. Based on the evidence presented here, strain GCAF-1T ( = DSM 23318T  = KCTC 5935T) represents a novel species of the genus Clostridium, for which the name Clostridium chromiireducens sp. nov. is proposed.


2017 ◽  
Vol 4 (2) ◽  
pp. 183-186
Author(s):  
Prabhakaran J ◽  
Kavitha D

An experiment was conducted in order to determine the allelopathic effects of the aqueous extract of Trianthima portulacastrum L.on the seed germination, seedling growth and chlorophyll content ofsesame (Sesamum indicum L.). Greenhouse experiment was carried out as RCBD (Randomized complete block design)with four replications. Treatments included 0, 1, 2, 3 and 4% (W/W) residues of whole plant of T.portulacastrum with normal field soil. Results showed that the low concentrations of T.portulacastrum had no significant effect on the germination percentage, seedling length, dry weight, total chlorophyll contents at lower concentration(1%) of weed residues. However, treatments with higher concentrations had negative effects on germination, growth and seedling dry weight of sesame.


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