Assessment of enrichment, geo-accumulation and ecological risk of heavy metals in surface sediments of the Msimbazi mangrove ecosystem, coast of Dar es Salaam, Tanzania

2019 ◽  
Vol 35 (9) ◽  
pp. 835-845 ◽  
Author(s):  
Shovi Furaeli Sawe ◽  
Daniel Abel Shilla ◽  
John Ferdinand Machiwa
Water ◽  
2021 ◽  
Vol 13 (13) ◽  
pp. 1801
Author(s):  
Valentina Andreea Calmuc ◽  
Madalina Calmuc ◽  
Maxim Arseni ◽  
Catalina Maria Topa ◽  
Mihaela Timofti ◽  
...  

It is a well–known fact that heavy metal pollution in sediments causes serious problems not only in the Danube basin, but also in the large and small adjacent river streams. A suitable method for assessing the level of heavy metals and their toxicity in sediments is the calculation of pollution indices. The present research aims to assess heavy metal pollution in the Lower Danube surface sediments collected along the Danube course (between 180 and 60 km) up to the point where the Danube River flows into the Danube Delta Biosphere Reserve (a United Nations Educational, Scientific and Cultural Organization – UNESCO, protected area). In addition, this monitored area is one of the largest European hydrographic basins. Five heavy metals (Cd, Ni, Zn, Pb, Cu) were analyzed in two different seasons, i.e., the autumn of 2018 and the spring of 2019, using the Inductively Coupled Plasma Mass Spectrometry (ICP– MS) technique. Our assessment of heavy metal pollution revealed two correlated aspects: 1. a determination of the potential risks of heavy metals in sediments by calculating the Potential Ecological Risk Index (RI), and 2. an evaluation of the influence of anthropogenic activities on the level of heavy metal contamination in the surface sediments, using three specific pollution indices, namely, the Geo–Accumulation Index (Igeo), the Contamination Factor (CF), and the Pollution Load Index (PLI). The results of this pioneering research activity in the region highlighted the presence of moderate metal (Ni and Cd) pollution and a low potential ecological risk for the aquatic environment.


2014 ◽  
Vol 675-677 ◽  
pp. 299-304
Author(s):  
Ren Jun Liang ◽  
Xiao Tian Ma ◽  
Ji Cai Qiu

This study assessed the ecological risk associated with heavy metals in surface sediments in a specific setting: the Wuhan wetland. Metals were extracted and characterized using the Tessier method, and the morphological distribution characteristics and correlation of Zn, Mn, Fe, Cr, and As were analyzed. The results indicated that heavy metals at the study site mainly exist in residual state forms; the Mn pollution was serious; the potential risk from Cr and As was larger; and the environmental risk from Fe and Zn was lower. In order of potential ecological harm: As > Zn > Cr > Mn. The overall risk of ecological harm was slight, but the individual region has seen moderate ecological damage because of As pollution. Because this element has a significant toxicity level, it is important to remain attentive to the pollution caused by it.


2020 ◽  
Vol 7 (10) ◽  
pp. 200538
Author(s):  
Hongxue Qi ◽  
Bingqing Zhao ◽  
Lihong Li ◽  
Xiuling Chen ◽  
Jing An ◽  
...  

To assess contamination levels and ecological risks of heavy metals in agricultural soil from Shanxi Province of China, a total of 33 samples in the surface soil were collected from 11 cities in Shanxi. The soil samples were digested by a mixed acid of nitric acid and hydrofluoric acid on a microwave digestion system, then the levels of eight heavy metals were analysed using an inductively coupled plasma mass spectrometer. The pollution levels of soil heavy metals were evaluated using a geo-accumulation index and their ecological risks were assessed using risk index calculated by Hakanson's method. As a result, the average concentrations of the heavy metals As, Cd, Cr, Cu, Hg, Ni, Pb and Zn were 12.9 ± 4.8, 0.35 ± 0.23, 43 ± 14, 27 ± 19, 0.25 ± 0.14, 21.7 ± 5.7, 17 ± 13 and 89 ± 53 mg kg −1 , respectively. By comparison to the Chinese soil environmental quality (GB15618-2018), only 9% of Cd samples and 3% of Cu samples exceeded their corresponding screening criteria. Subsequently, the results of geo-accumulation indices suggested that Shanxi's soil suffered from moderate to heavy contamination posed by Cd and Hg, and risk indices exhibited a similar trend that Cd and Hg were the main contributors for considerable to very high ecological risk. Finally, the analysis of variance indicated that the mean levels of Cd significantly occurred at Yuncheng areas among the 11 cities ( n = 3, p < 0.05), but Hg concentrations did not have significantly statistical differences. This study demonstrated that metals Cd and Hg had higher levels and ecological risks for agricultural soil in Shanxi, especially, Yuncheng City suffered from heavy Cd contamination. The findings of the present study will provide basic information on management and control of the agricultural soil contamination in Shanxi Province, China.


2020 ◽  
Vol 42 (9) ◽  
pp. 2747-2769 ◽  
Author(s):  
Christophoros Christophoridis ◽  
Emmanouil Evgenakis ◽  
Anna Bourliva ◽  
Lambrini Papadopoulou ◽  
Konstantinos Fytianos

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Jin Wei ◽  
Maoqing Duan ◽  
Yiping Li ◽  
Amechi S. Nwankwegu ◽  
Yong Ji ◽  
...  

Abstract Surface sediment samples were collected from four areas (the Jingdezhen Industrialized Area (JDZ), Upstream (UP), the Dexing Mining Area (DX), and Downstream (DM)) to investigate the concentration and chemical composition of heavy metals. The sediments were analysed for Cu, Zn, Pb, Cd, Cr, As, and Ni using a sequential extraction scheme according to the improved BCR (European Community Bureau of Reference) method. The obtained results show that the maximum values of Cu (793.52 μg·g−1), Zn (72.09 μg·g−1), Pb (222.19 μg·g−1), and Cd (1.60 μg·g−1) were collected from the DX sampling area, while the JDZ area had the highest concentrations of Cr (97.09 μg·g−1), As (318.05 μg·g−1), and Ni (66.35 μg·g−1). The majority of metal values far exceeded their corresponding background values. The risk analysis of geo-accumulation index (Igeo) indicated that the heavy metals Cu and As were the main pollution factors and each element of the pollution degree followed the order of: Cu > As > Pb > Cd > Cr > Zn. Metal partitioning characteristics were also considered and more than 80% of metals show potential bioavailability and toxic effects.


PLoS ONE ◽  
2014 ◽  
Vol 9 (7) ◽  
pp. e102101 ◽  
Author(s):  
Binbin Wu ◽  
Guoqiang Wang ◽  
Jin Wu ◽  
Qing Fu ◽  
Changming Liu

2019 ◽  
Vol 158 ◽  
pp. 130-139 ◽  
Author(s):  
Morteza Seifi ◽  
Amir Hossein Mahvi ◽  
Seyed Yaser Hashemi ◽  
Hossein Arfaeinia ◽  
Hasan Pasalari ◽  
...  

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