scholarly journals Ecological Risk Assessment of Potential Toxic Elements in Salt Marshes on the East Coast of the Red Sea: Differential Physiological Responses and Adaptation Capacities of Dominant Halophytes

2021 ◽  
Vol 13 (20) ◽  
pp. 11282
Author(s):  
Farag Ibraheem ◽  
Nawal Al-Hazmi ◽  
Mohamed El-Morsy ◽  
Ahmed Mosa

The impact of the mutual interactions between salinity and the phytoavailability of potential toxic elements (PTEs) on the adaptation of halophytes in their natural habitat is complex and far from clear. Herein, we aimed to evaluate salinity- and PTE-induced oxidative stress in selected halophytes and the antioxidant responses of these plants. For that, five salt marshes were selected, and the physiological responses of dominant halophytes (Tamarix nilotica, Heliotropium crispum, Zygophyllum coccineum, Halopeplus perfoliata, and Avicennia marina) were evaluated against the physicochemical features of their rhizosediments. The tested locations varied in their physicochemical properties and showed various levels of salinity stress and a low fertility status. Distinct variations in ten PTE concentrations were recognized among locations and within plants, with Cr and Co showing the highest ecological risk indices. The high levels of salinity and PTEs were associated with higher foliar levels of malondialdehyde, particularly in A. marina and Z. coccineum. The bio-concentration ratio revealed hyperaccumulating potentials of PTEs by the tested halophytes. Z. coccineum showed effective accumulation of Co, Fe, and Pb, while T. nilotica exhibited effective accumulation of Cu, Cd, and Zn. H. perfoliate had higher accumulation of Cr and Hg, whereas A. marina accumulated a significant amount of Hg, Cd, Zn, and Mn. H. crispum leaves accumulated the highest Ni levels among the tested halophytes. Altogether, our results highlight the potential risk of pollution of the tested areas with PTEs and the efficient physiological adaptation of each of the tested halophytes as a unique biological system. They also reflect the high capabilities of the tested halophytes as phytoextractors of their corresponding PTEs and their potential as efficient tools for phytoremediation of salt- and PTE-affected lands.

2021 ◽  
Author(s):  
Gevorg Tepanosyan ◽  
Norik Harutyunyan ◽  
Nairuhi Maghakyan ◽  
Lilit Sahakyan

Abstract This research aimed to assess the ecological status of the Hrazdan river section flowing through Yerevan. The distribution of toxic elements (Cr, V, As, Zn, Cu, Ni, Co, Mn, Pb, Ti, Mo, Fe, Ba), the bottom sediments pollution level and ecological risks, were assessed employing the contamination factor (CF), enrichment factor (EF), the potential ecological risk index (RI) and geoaccumulation index (Igeo). On sampling sites, water quality parameters (turbidity, DO, conductivity (EC), salinity, TDS, pH, T°C) were measured, as well. The correlation analysis revealed a significant correlation between Zn - Cu, Pb; Cu - Pb, Mo; Co - Fe, Ti pointing out the similar sources and origination of these elements. The results have indicated that the content of the studied elements in the Hrazdan bottom sediments exceed the background content in urban soils, which is due to a set of geological and anthropogenic factors. High contents of elements were determined on sampling sites spatially confined to the residential and industrial areas. According to EF and Igeo data, the priority bottom sediment contaminants are As, Pb, Mo, Zn, V, Cu. The RI value varies from 195.9 to 316.3 with the mean of 245.9 which corresponds to the moderate-level ecological risk. On the whole, a moderate (77.8%) and considerable (22.2%) ecological risk was revealed. An essential source of Pb, Cu, Zn, Mo contents was itentified to be the surface runoffs in urban environment.


Molecules ◽  
2019 ◽  
Vol 24 (11) ◽  
pp. 2145 ◽  
Author(s):  
Sanja Sakan ◽  
Nenad Sakan ◽  
Aleksandar Popović ◽  
Sandra Škrivanj ◽  
Dragana Đorđević

The need for further research into potentially toxic elements in Serbian rivers led to an investigation of distributions, sources, and ecological risks in a sample base of sediments from 15 rivers. The analyses were carried out through both experimental and theoretical methods. Geochemical fractionation of Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, As, V, and Zn in sediments was studied using a sequential extraction procedure. Both a Håkanson risk index (RI) and a Monte Carlo simulation (MCS) were used in order to estimate ecological risk, applying the probability distribution of RI values instead of single-point calculations. In order to both further the development of the used method and include additional processes, software for the simulations was developed instead of using proprietary solutions. Metal fractionation showed high percentage recoveries of Cd, Cr, Co, Cu, Fe, Ni, and V in residual fractions. The high content of Pb, Mn, and Zn in mobile fractions might cause serious environmental concerns. In some localities, Cu and Cd could be problematic elements, since their mobility was high. An environmental assessment based on the described criteria provided risk levels varying from low to median (mainly contributed by Cd and Cu).


2020 ◽  
Vol 18 (1) ◽  
pp. 77-96
Author(s):  
Hameed Alsamadany ◽  
Hassan S. Al-Zahrani ◽  
El-Metwally M. Selim ◽  
Mohsen M. El-Sherbiny

AbstractTo assess trace element concentrations (Zn, Cu, Pb, Cr, Cd and Ni) in the mangrove swamps along the Saudi coast of the Arabian Gulf, thirteen samples of surface sediment and leaves of grey mangrove, Avicennia marina were collected and analyzed. The detected trace element contents (μg g-1) in surface sediments were in the following descending order according to their mean values; Cr (49.18) > Zn (48.48) > Cu (43.06) > Pb (26.61) > Ni (22.88) > Cd (3.21). The results showed that the average concentrations of Cd and Pb exceeded their world average concentration of shale. The geo-accumulation, potential ecological risk and toxicity response indices demonstrated that trace elements have posed a considerable ecological risk, especially Cd. The inter-relationships between physico-chemical characters and trace elements suggests that grained particles of mud represent a noteworthy character in the distribution of trace elements compared to organic materials. Moreover, the results revealed that Zn was clearly bioaccumulated in leaf tissues A. marina. Dredging, landfilling, sewage effluents and oil pollution can be the paramount sources of pollution in the area under investigation.


Minerals ◽  
2021 ◽  
Vol 11 (3) ◽  
pp. 330
Author(s):  
Libo Pan ◽  
Xiao Guan ◽  
Bo Liu ◽  
Yanjun Chen ◽  
Ying Pei ◽  
...  

Acid mine drainage (AMD) from abandoned coal mines can lead to serious environmental problems due to its low pH and high concentrations of potentially toxic elements. In this study, soil pH, sulfur (S) content, and arsenic (As), cadmium (Cd), chromium (Cr), copper (Cu), lead (Pb), nickel (Ni), zinc (Zn), iron (Fe), manganese (Mn), and mercury (Hg) concentrations were measured in 27 surface soil samples from areas in which coal-mining activities ceased nine years previously in Youyu Catchment, Guizhou Province, China. The soil was acidic, with a mean pH of 5.28. Cadmium was the only element with a mean concentration higher than the national soil quality standard. As, Cd, Cu, Ni, Zn, Mn, Cr, and Fe concentrations were all higher than the background values in Guizhou Province. This was especially true for the Cd, Cu, and Fe concentrations, which were 1.69, 1.95, and 12.18 times their respective background values. The geoaccumulation index of Cd and Fe was present at unpolluted to moderately polluted and heavily polluted levels, respectively, indicating higher pollution levels than for the other elements in the study area. Spatially, significantly high Fe and S concentrations, as well as extremely low pH values, were found in the soils of the AMD sites; however, sites where tributaries merged with the Youyu River (TM) had the highest Cd pollution level. Iron originated mainly from non-point sources (e.g., AMD and coal gangues), while AMD and agricultural activity were the predominant sources of Cd. The results of an eco-risk assessment indicated that Cd levels presented a moderate potential ecological risk, while the other elements all posed a low risk. For the TM sites, the highest eco-risk was for Cd, with levels that could be harmful for aquatic organisms in the wet season, and may endanger human health via the food chain.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Hyeryeong Jeong ◽  
Jin Young Choi ◽  
Kongtae Ra

AbstractPotentially toxic elements (PTEs) were investigated in the different sizes of road deposited sediments (RDS) around the active smelting industry to understand their sources and to assess the pollution and ecological risk levels. The highest PTEs concentrations was shown near the raw materials import port and the smelting facilities. The fine particles of RDS showed extremely high PTEs concentrations. Zn has the highest mean concentration in the < 63 μm particle size of RDS, followed by Pb > Cu > As > Cr > Ni > Cd > Hg. The PTEs concentrations of this study were the highest values compared to the soils around the smelter and the RDS in urban and industrial areas in the world. This indicates that these PTEs pollution in RDS were mainly attributed to the transportation of raw materials for the smelting industry. According to nemerow pollution index calculation, RDS at all sampling sites with particles of less than 250 mm was seriously polluted with PTEs. The ecological risk was also found to be very high in all RDS fractions and highly toxic elements such as Cd, Pb and Hg pose extremely risk. Given the total amounts PTEs in the road surface, it is necessary to apply RDS removal management plan to reduce the PTEs pollution.


2019 ◽  
Vol 64 (01) ◽  
pp. 175-190
Author(s):  
JR-TSUNG HUANG ◽  
JIUN-NAN PAN ◽  
MING-LEI CHANG ◽  
SHIH-YI YOU

Since the economic consequences of a low fertility rate, such as a change in consumption patterns, might affect the path of economic growth, this study investigates how the relationship between the low fertility rate and consumption behavior in Taiwan has changed over time. Using county-level panel data from 1995 to 2014 to examine the impact of the low fertility rate on the consumption behavior of households in Taiwan, the major finding of this study is that a low fertility rate will change the behavior and the composition of consumption. A low fertility rate will increase the share of the total consumption expenditure in a household’s disposable income, in particular, in relation to the consumption categories of food, health care, education, and transportation and communication, but will decrease the share of expenditure on clothing in the household’s disposable income.


Author(s):  
Masahiro Horiuchi ◽  
Chieko Takiguchi ◽  
Yoko Kirihara ◽  
Yukari Horiuchi

We investigated the impact of wearing vs. not wearing graduated compression stockings on psychological and physiological responses in 18 healthy young people (12 men and six women) during 3 h prolonged sitting. Profiled of Mood States (POMS) scores did not show marked differences between with and without stockings. A 3 h sit significantly decreased saliva cortisol in both conditions; with no differences between conditions. Wearing stockings suppressed a subjective uncomfortable sensation (e.g., pain; fatigue; swelling) in the lower limbs, as assessed by visual analogue scale (VAS). Increase in heart rate at 1 h and 3 h was significantly greater without than with stockings. In addition, high-frequency oscillations (HF: 0.15–0.4 Hz), used as an indicator of parasympathetic nerve activity, showed higher values with than without stockings throughout the 3 h sitting period—significantly higher at 1 h. When data for both conditions were pooled pre-to-post changes in saliva cortisol were positively associated with higher uncomfortable sensations of VAS in the lower limbs and negatively associated with changes in the Vigor subscale of POMS. Collectively, these findings suggest that wearing graduated compression stockings may benefit from subjective comfort and increased parasympathetic nerve activity.


Sign in / Sign up

Export Citation Format

Share Document