The replacement of the nondescript term ‘heavy metals’ by a biologically and chemically significant classification of metal ions

Nieboer, Evert; Richardson, D. H. S.

doi:10.1016/0143-148x(80)90017-8

Cited by 1,051 publications

(534 citation statements)

References 61 publications

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“…The toxic effect of heavy metals, both essential and non-essential, depends on the type of target organism, the conditions of intake, the availability and concentration of the heavy metal and the kinetics of uptake, while the mechanisms of heavy-metal ion toxicity include the blocking of the functional group of biomolecules, displacing the essential metal ion in biomolecules, and modification of the active conformation of biomolecules (22). Heavy metals may affect cellular oxidation state, lipid peroxidation, breaking of DNA strands, protein expression and folding, degradation in proteasome, protein interactions, cell cycle and apoptosis; they are persistent and toxic, and they accumulate through the food chain (17,(23)(24)(25).…”

mentioning

confidence: 99%

Detection of heavy metals in common vegetables at Varaždin City Market, Croatia

Stančić

Vujević

Gomaz

et al. 2016

Archives of Industrial Hygiene and Toxicology

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The present study was aimed at the estimation of heavy metal content in vegetables sold at the city market of one of the densely populated Croatian cities, Varaždin, and to establish the relationship between their levels and possible sources of contamination. Twenty-eight samples of the most common diet vegetables (red and white potato, onion, carrot, common bean, lettuce, and cabbage) were randomly bought at the market in September and October 2013. Using the atomic absorption spectrometry method, concentrations of nine heavy metals (As, Cd, Cr, Cu, Hg, Mn, Ni, Pb, and Zn) were measured in the selected samples. The results showed that, in five out of 28 samples analysed, six concentrations exceeded the maximum levels provided for in the regulations: five for Pb and one for Cd. Maximum regulated levels for Pb were exceeded in two samples of red potato, two samples of common bean, and one sample of carrot (17.9 %), and for Cd in a sample of red potato (3.6 %). In conclusion, the cause of the overstepping of the maximum levels for Pb and Cd in the vegetables analysed was most likely the contaminated soil. The possible sources of soil contamination include traffic, nearby industry, floodwaters of rivers and streams, and the use of pesticides and fertilisers in agricultural production.

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mentioning

confidence: 99%

Detection of heavy metals in common vegetables at Varaždin City Market, Croatia

Stančić

Vujević

Gomaz

et al. 2016

Archives of Industrial Hygiene and Toxicology

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“…The fact that the K^ value obtained in Figure 6 a for extracellular Cd uptake in the absence of K was less than that obtained in Figure 7 b suggests that one of the Cdbinding sites in R. squarrosus has an affinity much higher than that suggested by the K^ value of 26 /IM. It is probable that this reflects in part the higher affinity of Cd for sulphydryl over carboxyl groups in the extracellular matrix (Nieboer & Richardson, 1980). The results imply that Cd and K display mutually exclusive binding to one exchange site and that binding of K to a different site reduces the number of functional Cd binding sites.…”

Section: K Interaction With CD Uptakementioning

confidence: 90%

“…Kinetic constants for intra-and extracellular Cd uptake were determined using procedures outlined by Wells & Brown (1987) (Nieboer & Richardson, 1980), we have shown that incubation in Cd solutions of 200 fiM or less for up to 30 min does not affect COg exchange or intracellular K concentrations in JR. squarrosus (Wells & Brown, 1987;Brown & Wells, 1990). ] Intracellular Cd uptake rates were determined by regression of Cd uptake against time for each concentration used.…”

Section: Determination Of Kinetic Constantsmentioning

confidence: 99%

Ionic control of intracellular and extracellular Cd uptake by the moss Rhytidiadelphus squarrosus (Hedw.) Warnst

Wells

Brown

1990

New Phytologist

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SUMMARYThe effects of K, Ca, Mg and H ions on the kinetics of Cd uptake by the moss Rhytidiadelphus squarrosus (Hedw.) Warnst were investigated. The affinity of extracellular exchange sites for these ions decreased in the order Cd, H > Ca > Mg > K and there were competitive interactions between ions. The affinity of the intracellular Cd transport site for these ions decreased in the order Ca > Cd > Mg > K. Calcium was shown to be competitive and Mg a non-competitive inhibitor of intracellular Cd uptake. Intracellular Cd uptake, optimal at about pH 5-6, was highly sensitive to pH, which primarily affected the V^^^. Potassium, supplied at less than 1 mM, had no significant effect on Cd uptake. However, at concentrations greater than 1 mM, KNO3 caused both a stimulation in transport site activity and reduced affinity for Cd.Pretreatment with KNO3 removed potentially competing ions from the cell wall, altering the subsequent chemical equilibria established when moss shoots were incubated in Cd solutions. Reduced competition from ions removed by KNO3 pretreatment resulted in a higher affinity of both transport sites and extracellular exchange sites for Cd, Ca and Mg. The results demonstrate quantitatively the regulatory effects on intracellular metal uptake of the extracellular ionic environment provided by the cell wall.

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“…• The borderline class: Zn, Pb, iron (Fe), chromium (Cr), cobalt (Co), Ni, As, vanadium (V), and tin (Sn) [127].…”

Section: Heavy Metals and Metalloidsmentioning

confidence: 99%

Effects on the Photosynthetic Activity of Algae after Exposure to Various Organic and Inorganic Pollutants: Review

Petsas¹,

Vagi²

2017

Chlorophyll

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Algal studies remain necessary for risk assessment and their utility in ecotoxicology is the evaluation of lethal and sub-lethal toxic effects of potential toxicants on inhabitants of several ecosystems. Effects on algal photosynthetic apparatus caused by various chemical species have been extensively studied. The present chapter summarizes the published data concerning the toxicity of various organic and inorganic pollutants such as oils, pesticides, antifoulants and metals on photosynthesis of aquatic primary producers. Biochemical mode of action resulting in the disruption of photosynthesis depends on the chemical's nature and the characteristics of the exposed microorganism. Observed differences in response and sensitivity by different species to the same toxicant were attributed to several algal characteristics including photosynthetic capacity, pigment type, cellular lipid and protein content, and cell size. Single species bioassays either for one chemical alone or in mixture have been well reported and tolerance of both marine and freshwater water-column phytoplaktonic species has been examined. Adequate published information on multispecies tests (communities) in laboratory and field studies exists. However, risk assessment on photosynthesis of microbenthic periphyton is inadequate, though it is essential especially for hydrophobic organic molecules. Further studies are required to evaluate the adverse effects of metabolites on aquatic microalgae.

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The replacement of the nondescript term ‘heavy metals’ by a biologically and chemically significant classification of metal ions

Cited by 1,051 publications

References 61 publications

Detection of heavy metals in common vegetables at Varaždin City Market, Croatia

Detection of heavy metals in common vegetables at Varaždin City Market, Croatia

Ionic control of intracellular and extracellular Cd uptake by the moss Rhytidiadelphus squarrosus (Hedw.) Warnst

Effects on the Photosynthetic Activity of Algae after Exposure to Various Organic and Inorganic Pollutants: Review

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