Impact of heavy metal contamination : An overview

2019 ◽  
Vol 25 (2) ◽  
Author(s):  
Subhash Chandra Yadav
Keyword(s):  
Heavy Metal ◽  
Food Chain ◽  
Metal Contamination ◽  
Management Practices ◽  
Heavy Metal Contamination ◽  
Oral Intake ◽  
Contaminated Site ◽  
Human Beings ◽  
Metabolic Activities ◽  
Management Approaches

The issue of heavy metal pollution is very much concerned because of their toxicity for plant, animal and human beings and their lack of biodegradability. Excess concentrations of heavy metals have adverse effects on plant metabolic activities hence affect the food production qualitatively and quantitatively. Heavy metal when reaches human tissues through various absorption pathways such as direct ingestion, dermal contact, diet through the soil-food chain, inhalation and oral intake may seriously affect their health. Therefore, several management practices are being applied to minimize metal toxicity by attenuating the availability of metal to the plants. Some of the traditional methods are either extremely costly or they are simply applied to isolate contaminated site. The biology-based technology like use of hypermental accumulator plants occurring naturally or created by transgenic technology, in recent years draw great attention to remediate heavy metal contamination. Recently applications of nanoparticle for metal remediation are also attracting great research interest due to their exceptional adsorption and mechanical properties and unique electrical property, highly chemical stability and large specific surface area. Thus, the present review deals with different management approaches to reduce level of metal contamination in soil and finally of the food chain

scholarly journals Heavy Metal Contamination in Soil: Sources, Accumulation in Vegetables and Remedial Measures: A Review

Agropedology ◽  
2019 ◽  
Vol 30 (2) ◽  
Author(s):  
Sandeep Kumar ◽  
◽  
Lal Chand Malav ◽  
Shiv Prasad ◽  
Sunita Yadav ◽  
...  
Keyword(s):  
Heavy Metal ◽  
Toxic Metals ◽  
Urban Areas ◽  
Metal Contamination ◽  
Industrial Development ◽  
Heavy Metal Contamination ◽  
Biological Activities ◽  
Vegetable Production ◽  
Human Beings ◽  
Negative Effects

Presently, rapid industrialization and mechanization create a lot of heavy metal pollution around the globe. Both anthropogenic and natural sources are responsible for the discharge of heavy metal in the environment. Anyhow, these toxic metals reach into soil, water bodies, plants and finally to human beings through the food chain. These toxic metals create several problems in plants and living beings after intake from the soil and get accumulated in their body. Heavy metals also exhibit toxic effects on soil biological activities by affecting key microbial processes and also hamper the activities of soil microbes. Recently, due to industrial development in urban areas, heavy metal contamination has become a serious threat to peri-urban agriculture prevalent for vegetable production. There has long been a need for decontamination of these agricultural resources and prevention from the further contamination to avert the negative effects on living beings. In this article, an attempt has been made to provide an extensive understanding about different sources of heavy metal, such as zinc (Zn), copper (Cu), lead (Pb) and cadmium (Cd) etc., in agro-ecosystem and their possible risks to soil and plants. An effort has been also made to present in brief information on remediation techniques specially phytoremediation through this review.

scholarly journals How the Soil Microbial Communities and Activities Respond to Long-Term Heavy Metal Contamination in Electroplating Contaminated Site

2021 ◽  
Vol 9 (2) ◽  
pp. 362 ◽  
Author(s):  
Wen-Jing Gong ◽  
Zi-Fan Niu ◽  
Xing-Run Wang ◽  
He-Ping Zhao
Keyword(s):  
Heavy Metal ◽  
Microbial Communities ◽  
Metal Contamination ◽  
Heavy Metal Contamination ◽  
Soil Microbial Communities ◽  
Contaminated Site ◽  
Rrna Gene ◽  
Soil Microbial ◽  
Cu And Zn

The effects of long-term heavy metal contamination on the soil biological processes and soil microbial communities were investigated in a typical electroplating site in Zhangjiakou, China. It was found that the soil of the electroplating plant at Zhangjiakou were heavily polluted by Cr, Cr (VI), Ni, Cu, and Zn, with concentrations ranged from 112.8 to 9727.2, 0 to 1083.3, 15.6 to 58.4, 10.8 to 510.0 and 69.6 to 631.6 mg/kg, respectively. Soil urease and phosphatase activities were significantly inhibited by the heavy metal contamination, while the microbial biomass carbon content and the bacterial community richness were much lower compared to noncontaminated samples, suggesting that the long-term heavy metal contamination had a severe negative effect on soil microorganisms. Differently, soil dehydrogenase was promoted in the presence of Chromate compared to noncontaminated samples. This might be due to the enrichment of Sphingomonadaceae, which have been proven to be able to secrete dehydrogenase. The high-throughput sequencing of the 16S rRNA gene documented that Proteobacteria, Actinobacteria, and Chloroflexi were the dominant bacterial phyla in the contaminated soil. The Spearman correlation analysis showed the Methylobacillus, Muribaculaceae, and Sphingomonadaceae were able to tolerate high concentrations of Cr, Cr (VI), Cu, and Zn, indicating their potential in soil remediation.

Compound Heavy Metal Contaminated Site Risk Assessment Based on Hazard Quotients

2011 ◽  
Vol 414 ◽  
pp. 5-15
Author(s):  
Xiao Nan Sun ◽  
Xiu Rong Chen ◽  
An Ping Liu ◽  
Shi Ming Lv ◽  
Xing Xing Yao
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Metal Contamination ◽  
Heavy Metal Contamination ◽  
Soil Layer ◽  
Contaminated Site ◽  
Sampling Point ◽  
Potential Health ◽  
Potential Health Risk ◽  
Site Use

On the basis of investigation of specific heavy metals contaminated site, use compound heavy metal hazard quotients to do a assessment for potential health risk. The primarily detected excessive heavy metals are Zn, Gr, Cu and Hg. Results indicate that: in the surface (0~30 cm) and subsurface (30~70 cm), the compound heavy metal hazard quotients of sampling point 7#, 12#, 13# 6#, 7#, 12#, and 13# are greater than 1, and soil exists heavy metal contamination; in 70cm~100cm soil layer, the hazard quotients of all monitoring points are less than 1, therefore in these layers soil is not contaminated, and there are no need for remediation. The result reflects compound heavy metal contamination directly, and provides a reference for later remediation work.

scholarly journals Structure of Sediment-Associated Microbial Communities along a Heavy-Metal Contamination Gradient in the Marine Environment

2005 ◽  
Vol 71 (2) ◽  
pp. 679-690 ◽  
Author(s):  
David C. Gillan ◽  
Bruno Danis ◽  
Philippe Pernet ◽  
Guillemette Joly ◽  
Philippe Dubois
Keyword(s):  
Heavy Metal ◽  
Marine Environment ◽  
Marine Sediments ◽  
Metal Contamination ◽  
Heavy Metal Contamination ◽  
Dry Weight ◽  
Contaminated Site ◽  
Wide Range ◽  
Metal Levels ◽  
Extractable Metals

ABSTRACT Microbial community composition and structure were characterized in marine sediments contaminated for >80 years with cadmium, copper, lead, and zinc. Four sampling sites that encompass a wide range of sediment metal loads were compared in a Norwegian fjord (Sørfjord). HCl-extractable metals and organic matter constantly decreased from the most contaminated site (S1) to the control site (S4). All sampling sites presented low polychlorinated biphenyl (PCB) concentrations (Σ7PCB < 7.0 ng g [dry weight]−1). The biomass ranged from 4.3 × 108 to 13.4 × 108 cells g (dry weight) of sediments−1 and was not correlated to metal levels. Denaturing gradient gel electrophoresis indicated that diversity was not affected by the contamination. The majority of the partial 16S rRNA sequences obtained were classified in the γ- and δ-Proteobacteria and in the Cytophaga-Flexibacter-Bacteroides (CFB) bacteria. Some sequences were closely related to other sequences from polluted marine sediments. The abundances of seven phylogenetic groups were determined by using fluorescent in situ hybridization (FISH). FISH was impaired in S1 by high levels of autofluorescing particles. For S2 to S4, the results indicated that the HCl-extractable Cu, Pb, and Zn were negatively correlated with the abundance of γ-Proteobacteria and CFB bacteria. δ-Proteobacteria were not correlated with HCl-extractable metals. Bacteria of the Desulfosarcina-Desulfococcus group were detected in every site and represented 6 to 14% of the DAPI (4′,6′-diamidino-2-phenylindole) counts. Although factors other than metals may explain the distribution observed, the information presented here may be useful in predicting long-term effects of heavy-metal contamination in the marine environment.

scholarly journals Environmental Heavy Metal Contamination in Some Selected Cocoa Plantations in Oyo State, Nigeria

2021 ◽  
pp. 1-6
Author(s):  
G. A. Adewoye ◽  
N. A. Amusa
Keyword(s):  
Heavy Metal ◽  
Metal Contamination ◽  
Management Practices ◽  
Heavy Metal Contamination ◽  
Contamination Factor ◽  
Pollution Load Index ◽  
Soil Samples ◽  
The State ◽  
Pests And Diseases ◽  
Frequent Use

The frequent use of copper-based pesticides for the control of cocoa pests and diseases by farmers in Oyo State, Nigeria has necessitated the determination of heavy metal contamination in soil samples obtained from randomly selected cocoa plantations in Longe, Abaagbo, Sikiti, Idi-Ope, Alaagba, and Idi-Ogun in the State. Presence and quantities of copper, chromium, cadmium, manganese, lead and zinc were assayed in the collected samples. Levels of contamination of each of the soil samples were also assessed using contamination factor, degree of contamination, index of geo-accumulation and pollution load index (PLI). Results obtained from the study revealed a gradual deterioration of the analyzed cocoa soils. The PLI values also gave an indication of pollution. Cocoa farmers in the State therefore need to be properly enlightened on the use of synthetic pesticides, and be encouraged to adopt integrated pest management practices that place less emphasis on the use of chemicals.

scholarly journals Comparative analysis of heavy metal contamination in some common tubers and vegetables of Kerala

2019 ◽  
Author(s):  
Silvy Mathew ◽  
P. T. Teenamol
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Comparative Analysis ◽  
Metal Contamination ◽  
Heavy Metal Contamination ◽  
Leafy Vegetables ◽  
Cadmium Content ◽  
Human Beings ◽  
Potential Health ◽  
Potential Health Risk

Leafy vegetables and tubers contaminated by heavy metals will cause potential health risk to human beings. An analysis was carried out to study the heavy metal contamination in tubers and leafy vegetables at Kottayam district, Kerala. The results indicated that higher levels of lead were recorded in all of the samples analyzed when compared to the WHO permissible limits (0.1 mg/kg) for tubers and leafy vegetables, except in Colocasia esculenta (L.) Schott., collected from Erattupetta market. Cadmium content was higher in both the tubers and leafy vegetables collected from Changanacherry market. Therefore, regular assessment of the accumulation of heavy metals in leafy vegetables and tubers is the need of the era.

scholarly journals Pollution Status of Pakistan: A Retrospective Review on Heavy Metal Contamination of Water, Soil, and Vegetables

2014 ◽  
Vol 2014 ◽  
pp. 1-29 ◽  
Author(s):  
Amir Waseem ◽  
Jahanzaib Arshad ◽  
Farhat Iqbal ◽  
Ashif Sajjad ◽  
Zahid Mehmood ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Human Health ◽  
Food Chain ◽  
Metal Contamination ◽  
Heavy Metal Contamination ◽  
Environmental Pollutants ◽  
Anthropogenic Pressure ◽  
Trace Heavy Metals ◽  
Iron And Zinc

Trace heavy metals, such as arsenic, cadmium, lead, chromium, nickel, and mercury, are important environmental pollutants, particularly in areas with high anthropogenic pressure. In addition to these metals, copper, manganese, iron, and zinc are also important trace micronutrients. The presence of trace heavy metals in the atmosphere, soil, and water can cause serious problems to all organisms, and the ubiquitous bioavailability of these heavy metal can result in bioaccumulation in the food chain which especially can be highly dangerous to human health. This study reviews the heavy metal contamination in several areas of Pakistan over the past few years, particularly to assess the heavy metal contamination in water (ground water, surface water, and waste water), soil, sediments, particulate matter, and vegetables. The listed contaminations affect the drinking water quality, ecological environment, and food chain. Moreover, the toxicity induced by contaminated water, soil, and vegetables poses serious threat to human health.

scholarly journals Heavy Metal Contaminations in Herbal Medicines: Determination, Comprehensive Risk Assessments, and Solutions

2020 ◽  
Author(s):  
Lu Luo ◽  
Bo Wang ◽  
Jingwen Jiang ◽  
Qin Huang ◽  
Zheng Yu ◽  
...  
Keyword(s):  
Risk Assessment ◽  
Heavy Metal ◽  
Exposure Assessment ◽  
Metal Contamination ◽  
Heavy Metal Contamination ◽  
Herbal Medicines ◽  
Carcinogenic Risk ◽  
Human Beings ◽  
Acceptable Risks ◽  
Carcinogenic Risk Assessment

Abstract Background: Heavy metal contamination in herbal medicines is a global threat to human beings especially at levels above known threshold concentrations.Methods: The concentrations of five heavy metals cadmium (Cd), lead (Pb), arsenic (As), mercury (Hg) and copper (Cu) were investigated using Inductively Coupled Plasma Optical Mass Spectrometry (ICP-MS) with 1773 samples. Exposure assessment, Non-carcinogenic risk assessment, and carcinogenic risk assessment were applied to measure their risks in human body.Results: According to Chinese Pharmacopoeia, 30.51% (541) samples were detected with at least one over-limit metal. The over-limit ratio for Pb was 5.75% (102), Cd at 4.96% (88), As at 4.17% (74), Hg at 3.78% (67), and of Cu, 1.75% (31). For exposure assessment, Pb, Cd, As, and Hg have resulted in higher than acceptable risks in 25 kinds of herbs. The maximal Estimated Daily Intake (EDI) of Pb in seven herbs, of Cd in five, of Hg in four, and As in three exceeded their corresponding Provisional Tolerable Daily Intakes (PTDI). In total 25 kinds of herbs present an unacceptable risk as assessed with the HQ (Hazard Quotient) or HI (Hazard Index). Particularly, Plantaginis herba (HI = 11.47) is more than 11 times over the limit.Conclusions: Heavy metal contamination in herbal medicines was borderline or higher than the safety level with the majority of the herbal plants were within acceptable risks. Notably, As posed the highest risk in all indicators including EDI, HI, and CR, inducing the most serious risks in all five metals. Herbal medicines Euodiae fructus, Plantaginis herba, and Desmodii styracifolii were considered the most risk-inducing herbal medicines. Therefore, it is of great advantage to establish universal standards and quality requirements for hazardous elements in herbal medicines so that this natural resource can continue and expand further, to benefit health globally.

Sign in / Sign up

Export Citation Format

Share Document