scholarly journals Contamination Levels of Potentially Toxic Elements and Foraminiferal Distribution Patterns in Lagos Lagoon: A Correlation Analysis

Water ◽  
2021 ◽  
Vol 14 (1) ◽  
pp. 37
Author(s):  
Olugbenga T. Fajemila ◽  
Michael Martínez-Colón ◽  
Nisan Sariaslan ◽  
Ivory S. Council ◽  
Tesleem O. Kolawole ◽  
...  

The ecological response of benthic foraminifera to bioavailable Potentially Toxic Elements (PTEs) was evaluated in Lagos Lagoon (Nigeria). We sampled and analyzed PTEs across Lagos Lagoon with the aim to investigate the extent of contaminated sediments, to document their distribution, and to explore the relationship between PTE concentration and the spatial distribution, composition, abundance, and species richness of benthic foraminifera biotas. PTE’s recordings showed a wide range reflecting a diffuse contamination, where Contamination and Enrichment Factor suggest low to extremely polluted sediments. Findings of a previous survey of the benthic foraminifera inhabiting Lagos Lagoon revealed diverse assemblages of benthic taxa, species-specific distribution patterns, gradients of species richness and abundance, and a disjunct distribution of agglutinated and hyaline-perforate/porcelaneous taxa along a pronounced salinity gradient. Correlation matrix analysis shows that except for Selenium, all PTE total concentrations positively correlate with mud and Total Organic Carbon (TOC) and two of the most abundant agglutinated taxa, Ammotium salsum, and Trochammina sp. 1. Moreover, both species display significant positive correlations with CrF4-CoF2-F3-F4-total-CuF4-total-NiF3-F4-total-AlF4-total-FeF3-F4-total-ZnF3-F4-total. On the other hand, both foraminifers correlate negatively with PbF4-SeF3-Setotal. The overall significant positive correlation of these PTEs suggests that they behave as micronutrients when complexed with organic matter. No significant positive correlation with none of the PTEs in any fraction was found for neither species richness nor for the most abundant hyaline perforate species (Ammonia aoteana). Some PTE fractions were found to correlate either positively or negatively with individual species, suggesting that they function as either micronutrients and/or stressors. The resulting Contamination Factor of the PTE total concentrations shows that only a few sample sites can be classified as “moderately” polluted for chromium, zinc, and copper and that all sampled sites are classified as “highly polluted” for selenium. The highest concentrations for Cr, Cu, Ni, and Zn were found towards the industrialized western part, an area that is characterized by moderate to high diversity but low abundances.

2021 ◽  
Author(s):  
Antonio Romero-Baena ◽  
Cinta Barba-Brioso ◽  
Alicia Ross ◽  
Isabel González

<p>Agricultural soils in mining areas usually accumulate potentially toxic elements (PTEs) that can become a health risk to humans by entering the trophic chain. In this study, five small agricultural plots close to Riotinto mines (SW Spain) were studied, with the aims of comparing the concentration of PTEs with respect to the regional (South Portuguese Zone) baseline and conducting availability studies in order to determine the contamination of soils. Chemical composition, total and clay mineralogy, and edaphic parameters were determined in topsoil and subsoil samples to characterize the soils, and single extractions were conducted to assess the mobility. The mineralogy of the soils was composed of quartz and phyllosilicates, with small amounts of feldspars and occasionally containing hematite and calcite. The texture ranged from sandy to silty loam, the pH was slightly acidic, and high contents of organic matter were found. Total concentrations of trace elements correlated with the texture, the content in iron oxy-hydroxides and the pH. The values of As, Pb, Cu, and Zn exceeded the regional baseline even in sites unaffected by mining. The results suggest that a widespread sampling is necessary to determine the local background. The most water-soluble element was As, due to the competition of organic matter for sorption sites. The content of Cu, Cr and Zn extracted with different methods were higher in sandy soils with low iron oxy-hydroxides content. Monoammonium phosphate and EDTA extractions seemed to remove elements from organic matter and iron oxy-hydroxides. The extracted fractions of As and metals reached up to 10-30 wt%.  Despite the high total concentrations of the element in soils, they generally showed low available proportions, especially with water and ammonium acetate extractants. The results suggest that the soils are not necessarily a risk to humans and higher investigation efforts are necessary to assess the availability of PTEs and their transfer to plants.</p>


2018 ◽  
Vol 33 (9) ◽  
pp. 1486-1492 ◽  
Author(s):  
Guilherme L. Scheffler ◽  
Nausheen W. Sadiq ◽  
Dirce Pozebon ◽  
Diane Beauchemin

The risk from potentially toxic elements in airborne particulate matter collected on air filters is assessed using a batch in vitro method.


2019 ◽  
Vol 70 (10) ◽  
pp. 1389 ◽  
Author(s):  
Shujin Guo ◽  
Xiaoxia Sun

Transparent exopolymer particles (TEPs) contribute to carbon export and can represent a significant part of the carbon pool, most notably in eutrophic systems. This study represents the first investigation of the concentrations and distribution of TEPs in the Changjiang (Yangtze River) estuary, one of the most eutrophic coastal seas in the world. The concentration of TEPs was determined on a seasonal basis (spring, summer and autumn), and the distribution patterns of TEPs were studied with respect to physical, chemical and biological conditions. Spatially, TEP concentrations exhibited a significant positive correlation with chlorophyll-a concentrations in spring and summer, which implies a consistent production of TEPs by phytoplankton cells. Vertically, TEP concentrations decreased gradually from the surface layer to the bottom layer in spring and summer, but were distributed homogenously in the water column in autumn. Values of nitrogen:phosphorus ratio (N:P) were found to have a significant positive correlation with TEP concentrations in summer, indicating that a P limitation would probably accelerate production and formation of TEPs. TEP-carbon (TEP-C) concentration was found to be similar to phytoplankton-C in the study area, highlighting the fact that TEP-C could represent a significant fraction of the particulate organic carbon pool in the Changjiang (Yangtze River) estuary.


Minerals ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 953
Author(s):  
Yang Yu ◽  
Wenqing Liu ◽  
Haijiang Luo ◽  
Lihuan He ◽  
Haijiang Liu ◽  
...  

In this study, soil and rice samples from 85 sites in six cities in Hunan Province were analyzed for Cu, Zn, Pb, Cd, Hg, Mn, and Co (total and bioavailable concentrations for soil) in July 2014. The results indicated that the total concentrations of Cu, Zn, Pb, Cd, and Hg in soil had increased significantly compared with the 1980s, and were correlated with their bioavailable concentrations in soil positively. The total concentrations of Cd and Co in soil were correlated with those in rice. Bioavailable concentrations of Cd, Mn, Co, Pb, and Cu represented 64.4%, 33.2%, 12.0%, 11.6%, and 6.1% of the total soil concentrations, respectively. The bioavailable concentrations of Cd and Co in soil had a extremely significant (p < 0.01) positive correlation with those in rice, suggesting that bioavailable concentrations was a better indicator for soil potentially toxic elements contamination. The pH values had a significant influence on the bioavailability of Cd and Cu and the amounts taken up by rice. The Cd contamination in 27.0% rice samples exceeded World Health Organization recommended thresholds. The results added basic pollution distribution data, further revealing the relationships of metals in soil and crops and would offer great help to the metallic pollution control in these areas.


2021 ◽  
Author(s):  
Kazeem A. Basheeru ◽  
Hussein K. Okoro ◽  
Folahan A. Adekola ◽  
Nasir Abdus-Salam

2011 ◽  
Vol 28 (1) ◽  
pp. 25-30 ◽  
Author(s):  
Li-ping LI ◽  
Nurbay Abdusalih ◽  
Shao-peng WANG ◽  
Zhi-heng WANG ◽  
Zhi-yao TANG

Diversity ◽  
2021 ◽  
Vol 13 (4) ◽  
pp. 170
Author(s):  
Gladys N. Benitez ◽  
Glenn D. Aguilar ◽  
Dan Blanchon

The spatial distribution of corticolous lichens on the iconic New Zealand pōhutukawa (Metrosideros excelsa) tree was investigated from a survey of urban parks and forests across the city of Auckland in the North Island of New Zealand. Lichens were identified from ten randomly selected trees at 20 sampling sites, with 10 sites classified as coastal and another 10 as inland sites. Lichen data were correlated with distance from sea, distance from major roads, distance from native forests, mean tree DBH (diameter at breast height) and the seven-year average of measured NO2 over the area. A total of 33 lichen species were found with coastal sites harboring significantly higher average lichen species per tree as well as higher site species richness. We found mild hotspots in two sites for average lichen species per tree and another two separate sites for species richness, with all hotspots at the coast. A positive correlation between lichen species richness and DBH was found. Sites in coastal locations were more similar to each other in terms of lichen community composition than they were to adjacent inland sites and some species were only found at coastal sites. The average number of lichen species per tree was negatively correlated with distance from the coast, suggesting that the characteristic lichen flora found on pōhutukawa may be reliant on coastal microclimates. There were no correlations with distance from major roads, and a slight positive correlation between NO2 levels and average lichen species per tree.


Author(s):  
Shufeng She ◽  
Bifeng Hu ◽  
Xianglin Zhang ◽  
Shuai Shao ◽  
Yefeng Jiang ◽  
...  

Potentially toxic elements (PTEs) pollution in the agricultural soil of China, especially in developed regions such as the Yangtze River Delta (YRD) in eastern China, has received increasing attention. However, there are few studies on the long-term assessment of soil pollution by PTEs over large regions. Therefore, in this study, a meta-analysis was conducted to evaluate the current state and temporal trend of PTEs pollution in the agricultural land of the Yangtze River Delta. Based on a review of 118 studies published between 1993 and 2020, the average concentrations of Cd, Hg, As, Pb, Cr, Cu, Zn, and Ni were found to be 0.25 mg kg−1, 0.14 mg kg−1, 8.14 mg kg−1, 32.32 mg kg−1, 68.84 mg kg−1, 32.58 mg kg−1, 92.35 mg kg−1, and 29.30 mg kg−1, respectively. Among these elements, only Cd and Hg showed significant accumulation compared with their background values. The eastern Yangtze River Delta showed a relatively high ecological risk due to intensive industrial activities. The contents of Cd, Pb, and Zn in soil showed an increasing trend from 1993 to 2000 and then showed a decreasing trend. The results obtained from this study will provide guidance for the prevention and control of soil pollution in the Yangtze River Delta.


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