Heavy Metal Contamination as a Global Problem and the Need for Prevention/Reduction Measurements

Mansour, Sameeh A.

doi:10.1002/9781118474563.ch14

Cited by 6 publications

(3 citation statements)

References 83 publications

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“…Toxic heavy metals (HMs) as a factor of environmental pollution are still one of the main problems of the present day. 1,2 Their high toxicity at relatively low concentrations 3 and their exceptionally large bioaccumulation ability 4 have a harmful effect not only on individual living creatures, 5,6 but also on the planetary ecosystem. 7,8 In response to this global challenge, the World Health Organization (WHO) has implemented environmental regulations to protect humankind from the most dangerous heavy metal pollutants.…”

Section: Introductionmentioning

confidence: 99%

Interband transitions in closed-shell vacancy containing graphene quantum dots complexed with heavy metals

Shtepliuk

Yakimova

2018

Phys. Chem. Chem. Phys.

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High-performance optical detection of toxic heavy metals by using graphene quantum dots (GQDs) requires a strong interaction between the metals and GQDs, which can be reached through a functionalization/immobilization procedure or doping effect. However, commonly used surface activation approaches induce toxicity into the analysis system and, therefore, are ineligible from the environmental point of view. Here, we show that artificial creation of vacancy-type defects in GQDs can be a helpful means of intentional control of the active sites available for reaction with cadmium (Cd), mercury (Hg) and lead (Pb). Using restricted density functional theory (DFT) and time-dependent DFT (TD-DFT) methods, we predict the effect of vacancy complexes not previously studied to describe the binding ability of GQDs towards metal adsorbates. We also show that the interband absorption in closed-shell GQDs complexed with Cd, Hg and Pb is strongly dependent on the vacancy type and can be efficiently tuned to attain the desired coloration of the analysis system. The results suggest that the vacancy defects play an important role in governing the hybridization between locally-excited (LE) and charge-transfer (CT) states of the GQDs. Based on the molecular orbital analysis and in-depth knowledge of excited states, the mechanisms underlying the interband absorption are discussed.

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Section: Introductionmentioning

confidence: 99%

Interband transitions in closed-shell vacancy containing graphene quantum dots complexed with heavy metals

Shtepliuk

Yakimova

2018

Phys. Chem. Chem. Phys.

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“…Heavy metals are typical pollutants in the environment, and they have received global attention because they are hazardous to human health [ 1 ]. Heavy-metal pollutants are introduced into the water environment through various natural and artificial sources, including household emissions and industrial emissions such as mining and smelting [ 2 ].…”

Section: Introductionmentioning

confidence: 99%

Time-Dependent Toxicity and Health Effects Mechanism of Cadmium to Three Green Algae

Yang²,

Zhao³

et al. 2022

IJERPH

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As algae are extremely sensitive to heavy-metal ions and can be critical biological indicators in the heavy-metal toxicity analyses conducted by environmental health researchers, this paper explores the sensitivity to temporal toxicity of three species of green algae: Scenedesmus obliquus, Chlorella pyrenoidosa, and Selenastrum capricornutum. The method of time-dependent microplate toxicity analysis was used to systematically investigate the changes in the toxicities of the three green-algae species induced by different concentrations of cadmium (Cd). The chlorophyll a content, antioxidant enzyme activity, and malondialdehyde (MDA) content in the algae were analyzed to explore the mechanism of Cd toxicity after 96 h of exposure. The results showed that the toxic effects of Cd on the three algae species were time-dependent. By comparing the toxic effect of Cd, indicated by pEC50 (the negative logarithm of EC50), on the algae species at four durations of exposure (24, 48, 72, and 96 h), this study found that the indicator organisms had different sensitivities to Cd. The order of sensitivity was C. pyrenoidosa > S. obliquus > S. capricornutum. Cd exposure had significant effects on the chlorophyll a and MDA content and on the enzyme activity of superoxide dismutase (SOD) and catalase (CAT) in the algae species. The chlorophyll a content in the cells of the algae decreased with increasing Cd concentration. The enzyme activity of CAT and content of MDA increased with increasing Cd concentration, which indicated that Cd had an oxidative stress effect on the three algae species.

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“…Heavy metal pollution is one of several serious global problems which effect environmental and human health [11][12]. The environment, and humans, can be exposed to heavy metals by agriculture, industries and medical use [13][14][15].…”

Section: Introductionmentioning

confidence: 99%

Assessment of Organophosphate and Carbamate Insecticides and Heavy Metal Contamination in Canal-Grown Water Morning Glory (Ipomoea aquatica Forssk) in Nakhon Nayok Province, Thailand

et al. 2020

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Excessive application of insecticides in agriculture has become an increasing trend in Thailand, where agriculture is common in the area. This problem leads to negative impacts on human health and environment. Therefore, this study focused on monitoring organophosphate and carbamate insecticides, and heavy metals (Cd, Cu, Pb, Ni, Hg, Zn and Mn) in Ipomoea aquatica Forssk, as well as water and soil from different canals in Ongkharak District, Nakhon Nayok Province, Thailand. The powder samples were prepared from roots, stems and leaves of Ipomoea aquatica Forssk, as well as soil. Then, anti-acetylcholinesterase activity of each sample was determined, and heavy metal contents were measured by atomic absorption spectrometry. The results showed that the highest anti-acetylcholinesterase activity was found in the soil samples, followed by those of leaves and stems, roots, and water, respectively. Additionally, the order of heavy metal concentration of stem and leaves, root, water and soil samples were Mn>Cu>Hg>Ni>Zn>Cd>Pb, Mn>Zn>Ni >Cu>Cd>Hg>Pb, Ni>Cu>Hg>Mn>Cd>Zn>Pb, and Mn>Cu>Ni>Zn>Pb>Cd>Hg, respectively. The concentration of Cu and Hg in stems and leaves were above the standard levels of Ministry of Public Health (2003), while Cu and Cd in root samples were above the standard levels. Additionally, the concentrations of Cd, Ni and Zn in all water samples were above the standard levels of Ministry of Natural Resources and Environment (1994), and the concentrations of Cu, Hg and Mn in certain water samples were above the standard levels. The translocation factors (TFroot and TFwater) and bioaccumulation factor (BAF) above 1 were observed in order of Cu>Ni>Cd>Zn>Mn, Mn>Zn>Ni >Cd, and Mn>Zn>Ni>Cd, respectively. The findings provide useful information to agricultural and public health authorities for a dialogue in policy development (i.e. the importation and use of pesticides) to minimize health risk of vulnerable population including farmers and nearby communities in the province, and thus strengthening equity in health.

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Heavy Metal Contamination as a Global Problem and the Need for Prevention/Reduction Measurements

Cited by 6 publications

References 83 publications

Interband transitions in closed-shell vacancy containing graphene quantum dots complexed with heavy metals

Interband transitions in closed-shell vacancy containing graphene quantum dots complexed with heavy metals

Time-Dependent Toxicity and Health Effects Mechanism of Cadmium to Three Green Algae

Assessment of Organophosphate and Carbamate Insecticides and Heavy Metal Contamination in Canal-Grown Water Morning Glory (Ipomoea aquatica Forssk) in Nakhon Nayok Province, Thailand

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