Bioaccumulation and changes of trace metals over the last two decades in marine organisms from Guangdong coastal regions, South China

Using empirical negative cumulative extropy and image quality assessment to determine the accumulation of elements in marine organisms

In this study, the assessment of metals absorption capacity by macroalgae using image analysis was investigated for the first time and compared with fish bioaccumulatio. Empirical cumulative entropy (ECE), and also empirical negative cumulative extropy (ENCEX) were used as a newly introduced (information-based) indices. The regression equation was obtained between fish tissue-seawater in muscle of Sphyraena putnamiae (ENCEX=0.2001BAF; R²=0.96); In the case of muscle of Liza subviridis, the regression model was as (ENCEX=0.1950BAF; R²=0.93). The regression equation was obtained between algae-sediment (ENCEX_{H. hamulosa}=0.2695BAF; R²=0.97). The studied indices showed a high accumulation of Hypnea hamulosa compared to the other algae (ECE=0.2601; ENCEX=0.3995). IQA method showed the same result exhibiting that the algae can be evaluated as a bio-indicator of element accumulation using image analysis. Image analysis can help us find macro algae with high absorption capacity without laboratory examinations.

Effect of iron ion configurations on Ni2+ removal in electrocoagulation

Electrocoagulation (EC) has been widely used to treat the heavy metal wastewater in industry. A novel process of sinusoidal alternating current electrocoagulation (SACC) is adopted to remove Ni²⁺ in wastewater in this study. The morphology of precipitates and the distribution of the main functional iron configurations were investigated. Ferron timed complex spectroscopy can identify the monomeric iron configurations [Fe(a)], oligomeric iron configurations [Fe(b)] and polymeric iron configurations [Fe(c)]. The optimal operating conditions of SACC process were determined through single-factor experiments. The maximum Ni²⁺ removal efficiency [Re(Ni²⁺)] was achieved under the conditions of pH₀=7, current density (j) = 7 A/m², electrolysis time (t) = 25 min, c₀(Ni²⁺) = 100 mg/L. At pH=7, the proportion of Fe(b) and Fe(c) in the system was 50.4 at.% and 23.1 at.%, respectively. In the SACC process, Fe(b) and Fe(c) are the main iron configurations in solution, while Fe(c) are the vast majority of the iron configurations in the direct current electrocoagulation (DCC) process. Re(Ni²⁺) is 99.56% for SACC and 98.75% for DCC under the same optimum conditions, respectively. The precipitates produced by SACC have a high proportion of Fe(b) configurations with spherical α-FeOOH and γ-FeOOH structures which contain abundant hydroxyl groups. Moreover, it is demonstrated that Fe(b) has better adsorption capacity than Fe(c) through adsorption experiments of methyl orange (MO) dye. Fe(a) configurations in the homogeneous solution had no effect on the removal of nickel.

Distribution, risk assessment, and quantitative source apportionment of heavy metals in surface sediments from the shelf of the northern South China Sea

The concentration of heavy metals (Cu, Pb, Zn, Cr, Co, and Ni) from 421 sediment samples from the shelf of the northern margin of the South China Sea (SNSCS) was analyzed. The heavy metal content and calculated potential ecological indicators (E_rⁱ < 40 and RI < 160) indicate that there is low potential ecological risk of heavy metal pollution in the SNSCS. The mean effects range-median quotient (M-ERM-Q) and hazard quotient (HQ) values of sediment toxicological characteristics indicate that heavy metals are a potential toxicological risk. The high-risk area is mainly distributed in the southwest of the nearshore SNSCS. The positive matrix factorization (PMF) analysis results showed that major contributors to heavy metal pollution were natural sources and anthropogenic activities in the SNSCS. The government should pay particular attention to the monitoring of heavy metals in the nearshore southwest of the SNSCS.

Distribution and source apportionment of toxic and trace elements in some benthic and pelagic coastal fish species in Karnaphuli River Estuary, Bangladesh: Risk to human health

The Karnaphuli River is one of the prime and most important streams in the southeastern part of Bangladesh. The favorable water current and the geographic location have rendered the Karnaphuly River estuary a suitable habitat and a breeding ground for diverse fish species. Reversely, this estuary has been polluted by discharges from many point and non-point sources due to its location in the catchment area of a heavily industrialized area, Chattagram port city. However, published research concerning the status of toxic and trace elements in some commercially important benthic and pelagic coastal fish species in Karnaphuli River estuary was not found in the existing literature. Therefore, it's an important field of study on the assessment of toxic and trace elements concentration in the commercially important benthic and pelagic coastal fish species and their health taxation in the Karnaphuli River Estuary. Energy dispersive X-ray fluorescence (ED-XRF) was used to quantify trace metal concentration in edible parts of the fish species. This study revealed that the rank of the trace metals concentration was as follows (mg/kg): Zn (37.1) > Mn (16.12) > V (11.16) > Cu (9.49) > Rb (5.62) > Pb (2.98) > Cr (1.59) > Co (1.17). The F-test showed that a significant difference at 95 % confidence level in the distribution pattern of trace metals concentration among the examined fish species in the study area. The metal pollution index (MPI) in the muscle of fishes were found to be in the following order: L. bata > P. monodon > T. cirratus > M. bleekeri > O. pabda > H. nehereus > L. calcarifer > P. argenteus > P. paradiseus > T. toli, and the MPIs for most of the benthic fish species were higher compared to the pelagic fishes. On the other hand, the examined fish species were significantly bio-accumulative with the highest bio-accumulation factor value for benthic species. The multivariate analysis identified that the sources of the trace metals were associated with anthropogenic activities. For the human health risk assessment concern, estimated daily intake, target hazard quotient and cancer-causing risk were estimated. The results for non-cancer hazardous index values were found to be lower than unity. On the other hand, the total cancer risk data ranging from 1.24E-05 to 1.70E-05 were fallen within the range for the threshold values (1.0E-06 to 1.0E-04). However, considering the suggested values set by the environmental and regulatory agencies, it has been recommended that no significant non-carcinogenic and cancer-causing health risk for humans was seen due to the consumption of the studied fish species.

Concentrations and risk assessment of metals and microplastics from antifouling paint particles in the coastal sediment of a marina in Simon's Town, South Africa

Maintenance of maritime vessels includes the removal of paint from hulls that are sources of metals, antifouling paint particles (APPs) and microplastics (MPs) that end up in the coastal environment. Simon's Town is a small urban town in False Bay, Cape Town, South Africa, where maritime activities take place (there is a naval harbour, marina and shipyard). The aim of this study was to measure metals, APPs and MPs in Simon's Town, to assess the impact of maritime activities and a storm water pipe in a sheltered marina. Sediment samples were collected from six sites during winter 2018. Sediment and extracted APPs were analysed for metal concentrations (Al, As, B, Ba, Cd, Co, Cr, Cu, Hg, Mo, Ni, Pb, Se, Sb, Sn, Sr, V and Zn) and MPs characterised based on type (shape and polymer), colour and size. Highest average metal concentrations in sediment for all sites were Fe (32228 ± SEM 4024), Al (12271 ± 1062) and Cu (1129 ± 407). Metals in paint particles were highest for Fe (80873 ± 19341), Cu (66762 ± 13082) and Zn (44910 ± 1400 µg/g). Metal and MP fragment concentrations were highest at the slipway of the shipyard, decreasing with increased distance from the slipway. MP filaments were highest close to the storm water outfall pipe. Our results suggest that shipyards are potential sources of metals and MP fragments (mainly APPs), with storm water pipes potential sources of MP filaments. Various indices applied to assess the potential impacts of metals and MPs suggest that these contaminants have the potential to adversely impact the intertidal ecosystem investigated.

Impact of malathion toxicity on the oxidative stress parameters of the black soldier fly Hermetia illucens (Linnaeus, 1758) (Diptera: Stratiomyidae)

The black soldier fly larvae (BSFL) may serve as a promising tool in the animals feed production industry. The input organic wastes may be contaminated by insecticides that affect both the insect’s mass rearing, and the animals feed process. Therefore, in the current study the assessment of oxidative stress parameters of the black soldier fly (BSF) were investigated to quantify the deleterious effect of malathion-contaminated kitchen waste (1:1 vegetable: fruit waste) container on the insect. The different developmental stages of insect (adult and larva) were exposed to different concentrations (0, 0.005, 0.01, 0.015, and 0.02 mg/mL) of malathion. The results showed that the mean value of the reactive oxygen species (ROS), which included hydrogen peroxide (H2O2) and superoxide anion radicals (O2^•-) concentrations were lower in larval stage than in adults, in all treated groups (0, 0.005, 0.01, 0.015, and 0.02 mg/mL malathion concentration). Also, the protein carbonyls amount and lipid peroxides levels were decreased in the 0.02 mg/mL Malathion compared to the control values. However, the cluster analysis revealed slight dissimilar patterns for control insects and the highest malathion concentration (0.02 mg/ml). These stage-related differences could occur from the different growth dynamic functions of larvae and adults. The larvae were distinguished by robust growth, and significant oxygen consumption. The results verified that oxidative stress parameters, especially protein carbonyls and α, α-diphenyl-β-picrylhydrazyl (DPPH) were promising, cheap, quick and cost-effective applications for determining the macromolecules damage, and antioxidant ability of H. illucens enclosed with malathion exposure. These findings described that malathion application induces macromolecules damage mediated through oxidative stress injury.

Stage-, sex- and tissue-related changes in H2O2, glutathione concentration, and glutathione-dependent enzymes activity in Aiolopus thalassinus (Orthoptera: Acrididae) from heavy metal polluted areas

This study is part of a large project carried out at the Cairo University, Egypt, and focused on assessing physiological and biochemical changes in Aiolopus thalassinus under the influence of environmental pollution with heavy metals (Pb, Cd, Cu, and Zn). The study aimed to investigate parameters related to maintaining redox balance, with particular emphasis on stage-, sex- and tissue-dependent differences in H₂O₂ and glutathione (GSH) levels and activity of selected enzymes involved in GSH metabolism. A noticeable increase in the concentration of H₂O₂ was found, especially in the gut of 5th instar nymphs and females from the highly polluted site. An increase in GSH concentration was significant, especially in the gut of adult A. thalassinus from the high polluted site. However, recycling of reduced form of glutathione in the gut by glutathione reductase (GR) was relevant only for females from the high polluted site. Nymphs and females generally showed higher glutathione S-transferase (GST) activity, especially in the gut. These stage- and sex-related differences can result from different growth dynamic and various reproductive functions of nymphs and both sexes. The digestive track is in direct contact with xenobiotics consumed with food. Nymphs are characterized by vigorous growth, they feed intensively, and their development processes are associated with substantial oxygen consumption. Also, maintaining the antioxidant system at a high level can be more important for females than males due to egg production over a long period. It appears that de novo GSH synthesis is a favorable and cost-effective adaptation mechanism for A. thalassinus living in the high polluted site.

Metal Accumulation Profile of Catharanthus roseus (L.) G.Don and Celosia argentea L. with EDTA Co-Application

The problem of metal-induced toxicity is proliferating with an increase in industrialization and urbanization. The buildup of metals results in severe environmental deterioration and harmful impacts on plant growth. In this study, we investigated the potential of two ornamental plants, Catharanthus roseus (L.) G.Don and Celosia argentea L., to tolerate and accumulate Ni, Cr, Cd, Pb, and Cu. These ornamental plants were grown in Hoagland’s nutrient solution containing metal loads (50 µM and 100 µM) alone and in combination with a synthetic chelator, ethylenediaminetetraacetic acid (EDTA) (2.5 mM). Plant growth and metal tolerance varied in both plant species for Ni, Cr, Cd, Pb, and Cu. C. roseus growth was better in treatments without EDTA, particularly in Ni, Cr, and Pb treatments, and Pb content increased in all parts of the plant. In contrast, Cd content decreased with EDTA addition. In C. argentea, the addition of EDTA resulted in improved plant biomass at both doses of Cu. In contrast, plant biomass reduced significantly in the case of Ni. In C. argentea, without EDTA, root length in Cd and Cu treatments was significantly lower than the control and other treatments. However, the addition of EDTA resulted in improved growth at both doses for Pb and Cu. Metal accumulation in C. argentea enhanced significantly with EDTA addition at both doses of Cu and Cd. Hence, it can be concluded that EDTA addition resulted in improved growth and better metal uptake than treatments without EDTA. Metal accumulation increased with EDTA addition compared to treatments without EDTA, particularly for Pb in C. roseus and Cu and Cd in C. argentea. Based on the present results, C. roseus showed a better ability to phytostabilize Cu, Cd, and Ni, while C. argentea worked better for Ni, Cd, Cu, and Pb.

Empirical cumulative entropy as a new trace elements indicator to determine the relationship between algae-sediment pollution in the Persian Gulf, southern Iran

In this paper, the amount of 19 elements in three species of algae and associated sediment in the northern margin of the Persian Gulf was investigated. A sampling of algae was performed on the coast with a length of 5 km in each station and surface sediment was sampled at the same time in low and middle intertidal zones. The values of elements in the samples were measured by using an inductively coupled plasma mass spectrometry (ICP-MS) device. Then, the amount of bioaccumulation factor in algae tissue relative to sediment (biota-sediment accumulation factor, BSAF) was determined. The value of BSAF was compared with the empirical cumulative entropy (ECE). ECE is based on comparing the element information in algae with those in sediments. The results showed that BSAF was very closely related to the ECE factor so that significant correlations were obtained for algae species of P. gymnospora (ECE = 0.477 BSAF, R²: 0.967), H. hamulosa (ECE = 0.542 BSAF, R²: 0.979), and C. membranacea (ECE = 0.356 BSAF, R²: 0.976). The ECE values > 0.4 were similar to those obtained for BSAF > 1, exhibiting that the element accumulation in algae was higher than in sediments. Based on ECE, to determine the vanadium accumulation in the environment, the C. membranacea algae are more appropriate than H. hamulosa. Overall, the data showed that ECE is a good alternative to BSAF in estimating marine pollution.