scholarly journals Sequential Extraction and Risk Assessment of Potentially Toxic Elements in River Sediments

Minerals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 874
Author(s):  
Dithobolong L. Matabane ◽  
Taddese W. Godeto ◽  
Richard M. Mampa ◽  
Abayneh A. Ambushe
Keyword(s):  
Risk Assessment ◽  
Sequential Extraction ◽  
Extraction Method ◽  
Toxic Elements ◽  
River Sediments ◽  
Contamination Factor ◽  
Potentially Toxic Elements ◽  
Limpopo Province ◽  
Risk Level ◽  
Sequential Extraction Method

In this study, the sequential extraction method was applied to extract selected potentially toxic elements (PTEs) (Cd, Cr, Cu, Fe, Ni, Pb and Zn) in river sediments collected from the Blood River situated in Seshego area, Limpopo Province, South Africa. The study aimed to assess a possible trend of mobilisation of these elements from sediment to water. The accuracy of the sequential extraction method was confirmed by analysing sediment-certified reference material, and quantitative percentage recoveries ranging from 86 to 119%, 81 to 111% and 77 to 119% were achieved for exchangeable, reducible and oxidisable fractions, respectively. The potential risk of the PTEs in sediments was evaluated. The calculated values of contamination factor (CF) as well as risk assessment code (RAC) for Cd, Cu, Ni and Pb revealed the mobility of these elements. The PTEs in river sediments are at a high toxicity-risk level and could therefore cause a threat to organisms dwelling in sediments and humans via consumption of crops irrigated with the polluted river water.

scholarly journals Human Health Risk Assessment for Exposure to Potentially Toxic Elements in Polluted Rivers in the Ecuadorian Amazon

Water ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 613
Author(s):  
Samantha Jiménez-Oyola ◽  
Kenny Escobar Segovia ◽  
María-Jesús García-Martínez ◽  
Marcelo Ortega ◽  
David Bolonio ◽  
...  
Keyword(s):  
Risk Assessment ◽  
Cancer Risk ◽  
Health Risk ◽  
Human Health ◽  
Health Risk Assessment ◽  
Toxic Elements ◽  
Human Health Risk ◽  
Potentially Toxic Elements ◽  
Ecuadorian Amazon ◽  
Polluted Rivers

Anthropogenic activities performed in the Ecuadorian Amazon have released potentially toxic elements (PTEs) into the rivers, causing severe environmental pollution and increasing the risk of exposure to the residents of the surrounding areas. This study aims to carry out a human health risk assessment using deterministic and probabilistic methods to estimate the hazard index (HI) and total cancer risk (TCR) related to multi-pathway human exposure to PTEs in polluted rivers. Concentrations of Al, Cd, Cr, Cu, Hg, Ni, Pb, and Zn in surface water and sediment samples from rivers on the Ecuadorian Amazon were considered to assess the potential adverse human health effects. As a result, deterministic and probabilistic estimations of cancer and non-cancer risk through exposure to surface waters and sediments were above the safety limit. A sensitivity analysis identified the concentration of PTEs and the exposure duration (ED) as the two most important variables for probabilistic health risk assessment. The highest risk for receptors was related to exposure to polluted sediments through incidental ingestion and dermal contact routes. According to the deterministic estimation, the human health risk through ingestion of water was above the threshold in specific locations. This study reveals the potential health risk to which the population is exposed. This information can be used as a baseline to develop public strategies to reduce anthropogenic pollution and exposure to PTEs in Ecuadorian Amazon rivers.

Environmental Availability of Potentially Toxic Elements in an Agricultural Mediterranean Site

2019 ◽  
Vol 25 (2) ◽  
pp. 169-178 ◽  
Author(s):  
Dimitrios Alexakis ◽  
Dimitra Gamvroula ◽  
Eleni Theofili
Keyword(s):  
Sequential Extraction ◽  
Toxic Elements ◽  
Soil Depth ◽  
Extraction Procedure ◽  
Potential Ecological Risk ◽  
Potentially Toxic Elements ◽  
Geochemical Partitioning ◽  
Exchangeable Fraction ◽  
High Bioavailability

ABSTRACT Total contents of 36 potentially toxic elements are summarized for agricultural topsoil (n = 12; soil depth = 0–20 cm), subsoil (n = 12; soil depth = 20–40 cm), and representative rock samples collected from a Mediterranean site (Megara Plain, Greece). The five-stage sequential extraction procedure for the geochemical partitioning of cadmium (Cd), cobalt (Co), chromium (Cr), copper (Cu), manganese (Mn), and nickel (Ni), proposed by Tessier, was applied to topsoil and subsoil collected from the study area. Soil Cd was highly associated with exchangeable fraction, illustrating high bioavailability of this element. The order of mobility of the elements was as follows: Cd > Cu > Co > Zn > Ni > Cr > Mn. Results from sequential extraction experiments illustrated that the bioavailability of Cu, Co, and Zn is moderate, while Ni, Cr, and Mn presented low bioavailability, indicating that these elements could pose a limited threat to the quality of crops. Cadmium is the chief contamination controlling factor posing moderate potential ecological risk. The contamination sources of the examined elements are discussed.

Validation of an Arsenic Sequential Extraction Method for Evaluating Mobility in Sediments

2001 ◽  
Vol 35 (13) ◽  
pp. 2778-2784 ◽  
Author(s):  
N. E. Keon ◽  
C. H. Swartz ◽  
D. J. Brabander ◽  
C. Harvey ◽  
H. F. Hemond
Keyword(s):  
Sequential Extraction ◽  
Extraction Method ◽  
Sequential Extraction Method
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