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Arsenic (As) is a toxic metalloid that exhibits a varying degree of toxicity in plants depending upon the redox status of its species. Elemental arsenic [As(0)] is the least toxic of all the As species, however, under conducive environmental conditions, it can be readily oxidized into toxic forms. The present experiment was designed to evaluate the deleterious effects of As when applied in As(0) form on the morpho-physiological attributes of Kalongi (Nigella sativa). Seeds of N. sativa were sown in soil contaminated with various levels of As (0, 1.875, 3.75, 7.5, 15.0, and 30.0 mg nA(0) kg -1 soil). The results indicated that plant biomass and grain yield of N. sativa were not much affected by various levels of As except at 30 mg nA(0) kg -1 soil. Activities of antioxidant enzymes (SOD, APX, POX, and CAT), phenolic contents, and carotenoids were enhanced in response to the overproduction of H 2 O 2 , subsequently inhibiting lipid peroxidation. Arsenic accumulation in different plant organs increased with increasing soil As levels in the given trend root > shoot > leaf > seedpod > seed. Arsenic uptake affected the uptake of other elements (P, Fe, Zn, K, Na, Ca). Adaptive changes in total chlorophyll contents, MDA contents, and antioxidant enzymatic defense mechanism in response to As stress suggest that the N. sativa is tolerant to moderate As stress. Therefore, this crop can be cultivated on moderately As-contaminated soils without any significant risks of economic losses and food chain contamination., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

Arsenic (As) is a toxic metalloid and its widespread contamination in agricultural soils along with soil salinization has become a serious concern for human health and food security. In the present study, the effect of cotton shell biochar (CSBC) in decreasing As-induced phytotoxicity and human health risks in quinoa (Chenopodium quinoa Willd.) grown on As-spiked saline and non-saline soils was evaluated. Quinoa plants were grown on As contaminated (0, 15 and 30 mg kg -1 ) saline and non-saline soils amended with 0, 1 and 2% CSBC. Results showed that plant growth, grain yield, stomatal conductance and chlorophyll contents of quinoa showed more decline on As contaminated saline soil than non-saline soil. The application of 2% CSBC particularly enhanced plant growth, leaf relative water contents, stomatal conductance, pigment contents and limited the uptake of As and Na as compared to soil without CSBC. Salinity in combination with As trigged the production of H 2 O 2 and caused lipid peroxidation of cell membranes. Biochar ameliorated the oxidative stress by increasing the activities of antioxidant enzymes (SOD, POD, CAT). Carcinogenic and non-carcinogenic human health risks were greatly decreased in the presence of biochar. Application of 2% CSBC showed promising results in reducing human health risks and As toxicity in quinoa grown on As contaminated non-saline and saline soils. Further research is needed to evaluate the role of biochar in minimizing As accumulation in other crops on normal as well as salt affected soils under field conditions., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

Despite considerable research of arsenic (As) level in ground/drinking water of Pakistan, scarce data is available regarding irrigation water contamination by As and associated health risks. The municipal wastewater is routinely applied for soil irrigation in peri-urban agriculture of the country. Since the wastewater composition/contamination and its allied consequences greatly vary in different areas, therefore, it is imperative to check the possible health risks in areas where untreated wastewater is being applied for food crop production. This study analyzed potential health hazards of As-buildup in soil and food plants irrigated with municipal wastewater growing under natural conditions. Sixteen wastewater irrigation locations were selected in District Vehari. From these sites, a total of 16 wastewater samples, 108 soil samples and 65 plant samples were collected for As analysis. Total As contents in wastewater (5.3-63.6 μg/L), soil (1.4-19.6 mg/kg) and plants (0-6.5 mg/kg) greatly varied with sampling location, soil depths and plant type. Based on total As contents in edible tissues, risk assessment parameters, especially cancer risk factor, showed possible health risks (> 0.0001) for wheat crops for children while no risks for other food crops. The use of multiple and diversified food crops is recommended in the study area to minimize the possible risk of As exposure and poisoning. The study also anticipates some future viewpoints considering the on-ground situation of wastewater use, possible exposure of metal(loid)s to human and associated health concerns at local and global scale., Competing Interests: Declaration of competing interest The authors declare that they do not know any competing conflict of interest that could have appeared to influence the work reported in this paper., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Arsenic (As) is a potentially toxic and carcinogenic metalloid. It has gained considerable attention owing to its high ecotoxic nature. High As contamination of groundwater in scattered areas is the current status of Pakistan. A number of assessments exist for the As contamination of the drinking water in District Vehari, Pakistan. However, there is scarcity of data about As contents in drinking water of health facilities and healthcare centers in District Vehari. The current study, therefore, was carried out to assess As concentration and associated health risk in the drinking water of three health facilities (district head quarter, rural health center and basic health unit) of District Vehari. In total, 75 drinking water samples were collected and examined for As contents in addition to physicochemical characteristics such as electrical conductivity, pH, total soluble salts, chloride, carbonates, bicarbonates, fluoride, nitrate, nitrite, calcium, magnesium and iron. Results indicated that the groundwater samples are not fully fit for drinking purposes with respect to several parameters, especially the alarming levels of As. It was found that 52% of drinking water samples of Vehari have As concentration greater than WHO permissible limit (10 µg/L) and 17% have As concentration greater than Pak-EPA permissible limit (50 µg/L). The risk assessment parameters (average daily dose, hazard quotient and carcinogenic risk) showed possible carcinogenic and non-carcinogenic risks associated with ingestion of As-contaminated drinking water in the healthcare facilities. Based on the results of the present study, it is anticipated that hospitals and health centers in Vehari are in need of safe drinking water. The implementation of national/international standards for drinking water in healthcare facilities is a necessary measure to improve the services and increase local access to safe drinking water. The same may be applied to other public offices and organizations such as educational institutes and district government offices.

The present study is the first attempt to evaluate the potential of acid and base activated biochar derived from cotton stalks (CSB) for the removal of As from contaminated water. The CSB was treated with 0.5 M KOH (BCSB) and H 3 PO 4 (ACSB) separately to change its surface properties. The CSB, ACSB and BSCB were characterized using BET, FTIR, and SEM analysis to check the effectiveness and insight of the main mechanisms involved in the removal of As. A series of batch experiments was performed using As-contaminated synthetic water and groundwater samples. The effects of initial concentration of As, contact time, dose of the biochars, solution pH, type of the biochar and coexisting ions on the removal of As were investigated. Results revealed that BCSB efficiently removed As (90-99.5%) from contaminated water as compared with ACSB (84-98%) and CSB (81-98%) due to improved surface properties when As concentration was varied from 0.1 to 4.0 mg/L. The experimental data were best fitted with Freundlich adsorption isotherm as compared with Langmuir, Temkin and Dubinin-Radushkevich models. However, kinetic data were well explained with pseudo-second-order kinetic model rather than pseudo-first-order, intra-particle diffusion and Elovich models. The sorption energy indicated that physical adsorption was involved in the removal of As. The comparison of adsorption results with other biochars and their modified forms suggests that activation of CSB with base can be used effectively (4.48 mg/g) as a low-cost adsorbent for maximum removal of As from contaminated aqueous systems.

Soil salinity and arsenic (As) contamination are serious environmental problems. To investigate the effects of salinity on As uptake and physiological and biochemical attributes of quinoa (Chenopodiumquinoa Willd.), a hydroponic experiment was performed. One-month old healthy plants of two quinoa genotypes; Vikinga and A7 were transplanted in plastic tubs containing half strength Hoagland's nutrient solution. Plants were exposed to different levels of As (0, 150 and 300 μM), salinity (0, 150 and 300 mM) and their combinations (150 μM As + 300 mM NaCl; 300 μM As + 300 mM NaCl) for five weeks. Results revealed that combined application of salinity and As caused more pronounced reduction in growth, chlorophyll contents and caused more oxidative damage in both quinoa genotypes. Under combined application of salinity and As, Na + concentration was increased whereas As content was decreased in plant tissues. Quinoa genotype A7 was more tolerant than Vikinga against salinity, As and their combination perhaps because of less uptake of toxic ions and higher activities of antioxidant enzymes (SOD, CAT, POD). Bioconcentration factor (BCF), translocation factor (TF) and tolerance index (TI) indicated that genotype A7 can be successfully employed for phytostabilization of As contaminated saline soils., (Copyright © 2019 Elsevier Inc. All rights reserved.)

Atmospheric contamination by heavy metal(loid)-enriched particulate matter (metal-PM) is highly topical these days because of its high persistence, toxic nature, and health risks. Globally, foliar uptake of metal(loid)s occurs for vegetables/crops grown in the vicinity of industrial or urban areas with a metal-PM-contaminated atmosphere. The current study evaluated the foliar uptake of arsenic (As), accumulation of As in different plant organs, its toxicity (in terms of ROS generation, chlorophyll degradation, and lipid peroxidation), and its defensive mechanism (antioxidant enzymes) in spinach (Spinacia oleracea) after foliar application of As in the form of nanoparticles (As-NPs). The As-NPs were prepared using a chemical method. Results indicate that spinach can absorb As via foliar pathways (0.50 to 0.73 mg/kg in leaves) and can translocate it towards root tissues (0.35 to 0.68 mg/kg). However, health risk assessment parameters showed that the As level in the edible parts of spinach was below the critical limit (hazard quotient < 1). Despite low tissue level, As-NP exposure caused phytotoxicity in terms of a decrease in plant dry biomass (up to 84%) and pigment contents (up to 38%). Furthermore, several-fold higher activities of antioxidant enzymes were observed under metal stress than control. However, no significant variation was observed in the level of hydrogen peroxide (H 2 O 2 ), which can be its possible transformation to other forms of reactive oxygen species (ROS). It is proposed that As can be absorbed by spinach via foliar pathway and then disturbs the plant metabolism. Therefore, air quality needs to be considered and monitored continuously for the human health risk assessment and quality of vegetables cultivated on polluted soils (roadside and industrial vicinity). Graphical abstract ᅟ.

Environmental contamination with arsenic (As) is a global environmental, agricultural and health issue due to the highly toxic and carcinogenic nature of As. Exposure of plants to As, even at very low concentration, can cause many morphological, physiological, and biochemical changes. The recent research on As in the soil-plant system indicates that As toxicity to plants varies with its speciation in plants (e.g., arsenite, As(III); arsenate, As(V)), with the type of plant species, and with other soil factors controlling As accumulation in plants. Various plant species have different mechanisms of As(III) or As(V) uptake, toxicity, and detoxification. This review briefly describes the sources and global extent of As contamination and As speciation in soil. We discuss different mechanisms responsible for As(III) and As(V) uptake, toxicity, and detoxification in plants, at physiological, biochemical, and molecular levels. This review highlights the importance of the As-induced generation of reactive oxygen species (ROS), as well as their damaging impacts on plants at biochemical, genetic, and molecular levels. The role of different enzymatic (superoxide dismutase, catalase, glutathione reductase, and ascorbate peroxidase) and non-enzymatic (salicylic acid, proline, phytochelatins, glutathione, nitric oxide, and phosphorous) substances under As(III/V) stress have been delineated via conceptual models showing As translocation and toxicity pathways in plant species. Significantly, this review addresses the current, albeit partially understood, emerging aspects on (i) As-induced physiological, biochemical, and genotoxic mechanisms and responses in plants and (ii) the roles of different molecules in modulation of As-induced toxicities in plants. We also provide insight on some important research gaps that need to be filled to advance our scientific understanding in this area of research on As in soil-plant systems., Competing Interests: The authors declare no conflict of interest.

The present study was conducted to explore arsenic (As) tolerance and phytostabilization potential of the two tree species, buttonwood (Conocarpus erectus) and eastern cottonwood (Populus deltoides). Both plant species were grown in pots and were exposed to various soil As levels (control, 5, 10, 15, and 20 mg kg -1 ). The plants were harvested after 9 months for the evaluation of growth parameters as well as root and shoot As concentrations. With increasing soil As levels, plant height stress tolerance index (PHSTI) was significantly decreased in both tree species, whereas root length stress tolerance index (RLSTI) and dry matter stress tolerance index (DMSTI) were not affected. Root and shoot As concentrations significantly increased in both tree species with increasing soil As levels. Translocation factor and bioconcentration factor were less than 1.0 for both plant species. This study revealed that both tree species are non-hyperaccumulators of As, but they could be used for phytostabilization of As-contaminated soils.

In this study, we determined the effect of ethylenediaminetetraacetic acid (EDTA) and calcium (Ca) on arsenic (As) uptake and toxicity to Pisum sativum. Plants were treated with three levels of As (25, 125, and 250 µM) in the presence and absence of three levels of Ca (1, 5, and 10 mM) and EDTA (25, 125, and 250 µM). Exposure to As caused an overproduction of hydrogen peroxide (H 2 O 2 ) in roots and leaves, which induced lipid peroxidation and decreased pigment contents. Application of both Ca and EDTA significantly reduced As accumulation by pea, Ca being more effective in reducing As accumulation. Both Ca and EDTA enhanced As-induced H 2 O 2 production, but reduced lipid peroxidation. In the case of pigment contents, EDTA significantly reduced pigment contents, whereas Ca significantly enhanced pigment contents compared to As alone. The effect of As treatment in the presence and absence of EDTA and Ca was more pronounced in younger leaves compared to older leaves. The effect of amendments varied greatly with their applied levels, as well as type and age of plant organs. Importantly, due to possible precipitation of Ca-As compounds, the soils with higher levels of Ca ions are likely to be less prone to food chain contamination.

Metallic trace elements toxicity has been associated with a wide range of morphological abnormalities in fish, both in natural aquatic ecosystems and controlled environments. The bioaccumulation of metallic trace elements can have devastating effects on several aspects of fish health, encompassing physiological, reproductive, behavioural, and developmental functions. Considering the significant risks posed by metallic trace elements-induced toxicity to fish populations, this review aims to investigate the deleterious effects of prevalent metallic trace elements toxicants, such as mercury (Hg), cadmium (Cd), chromium (Cr), lead (Pb), arsenic (As), and copper (Cu), on the neurological, reproductive, embryonic, and tissue systems of fish. Employing diverse search engines and relevant keywords, an extensive review of in vitro and in vivo studies pertaining to metallic trace elements toxicity and its adverse consequences on fish and their organs was conducted. The findings indicate that Cd was the most prevalent metallic trace elements in aquatic environments, exerting the most severe impacts on various fish organs and systems, followed by Cu and Pb. Moreover, it was observed that different metals exhibited varying degrees and types of effects on fish. Given the profound adverse effects of metallic trace elements contamination in water, immediate measures need to be taken to mitigate water pollution stemming from the discharge of waste containing metallic trace elements from agricultural, industrial, and domestic water usage. This study also compares the most common methods for treating metallic trace elements contamination in water. [ABSTRACT FROM AUTHOR]

The increasing contamination of soil with arsenic (As), and salinity has become a menace to food security and human health. The current study investigates the comparative efficacy of plain biochar (BC), and silicon-nanoparticles doped biochar (SBC) for ameliorating the As and salinity-induced phytotoxicity in quinoa (Chenopodium quinoa Willd.) and associated human health risks. Quinoa was grown on normal and saline soils (ECe 12.4 dSm-1) contaminated with As (0, 20mg kg-1) and supplemented with 1% of BC or SBC. The results demonstrated that plant growth, grain yield, chlorophyll contents, and stomatal conductance of quinoa were decreased by 62, 44, 48, and 66%, respectively under the blended stress of As and salinity as compared to control. Contrary to this, the addition of BC to As-contaminated saline soil caused a 31 and 25% increase in plant biomass and grain yield. However, these attributes were increased by 45 and 38% with the addition of SBC. The H2O2 and TBARS contents were enhanced by 5 and 10-fold, respectively under the combined stress of As and salinity. The SBC proved to be more efficient than BC in decreasing oxidative stress through overexpressing of antioxidant enzymes. The activities of superoxide dismutase, peroxidase, and catalase were enhanced by 5.4, 4.6, and 11-fold with the addition of SBC in As-contaminated saline soil. Contamination of grains by As revealed both the non-carcinogenic and carcinogenic risks to human health, however, these effects wereminimized with the addition of SBC. As accumulation in grains was decreased by 65-fold and 25-fold, respectively for BC and SBC in addition to As-contaminated saline soil. The addition of SBC to saline soils contaminated with As for quinoa cultivation is an effective approach for decreasing the food chain contamination and improving food security. However, more research is warranted for the field evaluation of the effectiveness of SBC in abating As uptake in other food crops cultivated on As polluted normal and salt-affected soils. [ABSTRACT FROM AUTHOR]

An experimental study was ascertained in birds to assess the toxicological effects of arsenic (sodium arsenate) and urea alone or in different combinations. After two weeks of acclimatization, all the birds were randomly divided into six equal groups (T0-T5) each containing 15 birds. Arsenic (A) and urea (U) was given to chickens (mg/kg body weight) daily for 39 days as follow: T1 (A10U0.5), T2 (A15U0.75), T3 (A20U1.0), T4 (A25) and T5 (U1.5). Various signs of toxicity such as depression, dullness, tremors, watery droppings, gasping, anemic comb and wattle were prominent in treated birds. Feed consumption and body weight of experimental birds treated with arsenic and urea decreased significantly. The absolute and relative weights of different visceral organs such as heart, liver, kidneys, spleen and bursa of treated birds were decreased significantly. Histologically, tissue sections of liver showed necrosis of hepatocyte, fatty degeneration and mild congestion. Microscopically, necrosis of renal tubular epithelial cells, congestion and increased urinary spaces in kidneys, mild congestion in spleen and vacuolation in bursa of Fabricius of treated birds was evident. Hematological assessment indicated significant decrease in hemoglobin, erythrocyte count, hematocrit percent and mean corpuscular hemoglobin concentrations. Results revealed significant increase in serum cardiac iso-enzyme, triglycerides, cholesterol and malondialdehyde concentration in treated birds as compared to untreated birds. A significant decrease in serum total proteins while increased concentrations of alanine aminotransferase, asparatate aminotransferase, lactate dehydrogenase, creatinine and urea was estimated in treated birds. Significantly increased frequency of micronucleus and nuclear abnormalities in erythrocytes was recorded. It was concluded that arsenic and urea in combinations even at low levels affect clinical attributes, hemato-biochemical parameters and erythrocyte morphology in layer birds. [ABSTRACT FROM AUTHOR]

Purpose: This study delineated the effect of calcium (Ca) and ethylenediaminetetraacetic acid (EDTA) addition on arsenic (As) accumulation and physiological attributes of Vicia faba L.Materials and methods: Two separate experiments were performed. In the first experiment, V. faba seedlings, grown under hydroponic conditions, were exposed to three levels of As (25, 125 and 250 μM) in the presence and absence of three levels of EDTA (25, 125, 250 μM) and calcium (CaCl2: 1, 5 and 10 mM). The effect of EDTA and Ca on As accumulation and physiological attributes of V. faba was assessed by determining As contents in roots and shoot, chlorophyll contents, H2O2 contents, and lipid peroxidation in young and old leaves. In the second experiment, V. faba seeds were grown in As-contaminated sand culture using the same treatment plan.Results and discussion: The accumulation and toxicity of As to V. faba plants increased with increasing As levels in nutrient solution. Arsenic exposure enhanced the production of reactive oxygen species (ROS) in both roots and leaves, which resulted in lipid peroxidation and decreased chlorophyll contents. The presence of both EDTA and Ca, in general, significantly decreased As accumulation by V. faba seedlings, Ca being more effective than EDTA. Both the amendments decreased As-induced reactive oxygen species (ROS) production and lipid peroxidation. In the case of chlorophyll contents, EDTA significantly decreased chlorophyll contents, while Ca significantly increased chlorophyll contents compared to As. The effect of all the treatments was more pronounced in roots than leaves and in young leaves compared to old leaves.Conclusions: It is proposed that EDTA and Ca greatly affect As accumulation and toxicity to V. faba, and the effect varies greatly with their applied levels as well as type and age of plant organs. The germinating seedlings of V. faba may be preferred for risk assessment studies, while transplanting 1-week-old V. faba seedlings to As-contaminated soils can decrease its toxicity. [ABSTRACT FROM AUTHOR]

The objective of present experimental study was to ascertain the reproductive and some serum biochemical effects following oral administration of arsenic and copper sulfate in adult male birds. For this purpose, adult cockerels (Lohmann Selected White Leghorn) were randomly allotted into seven equal groups. The male birds were fed with a standard control diet containing 20% crude proteins. Arsenic and copper sulfate significantly (P≤0.05) decreased the absolute weight of testes, liver, kidneys, spleen, lungs, heart and thymus in male birds. Histologically, the liver was congested and showed extensive fatty infiltration and biliary hyperplasia. Kidneys showed renal tubular necrosis, hypertrophy of glomeruli, and congestion. Different microscopic changes such as necrosis nuclei of spermatids, admixture of necrotic spermatids and disorganization of seminiferous tubules along with arrest of spermatogenesis were observed in testicular tissues. Furthermore, arsenic and copper sulfate significantly decreased plasma proteins, serum total proteins, serum globulins and albumins concentrations in birds. Conversely, the concentrations of serum urea, creatinine and alkaline phosphatase were increased in birds given arsenic and copper sulfate. The concentrations of lipid peroxidation product (malondialdehyde), levels of liver enzyme (aspartate aminotransferase) and cardiac biomarkers (CK-MB, triglyceride and cholesterol) increased significantly in birds treated with arsenic and copper sulfate. In summary, we showed that subacute exposure of birds to arsenic and copper sulfate induced oxidative stress and different tissue changes in birds. [ABSTRACT FROM AUTHOR]

Recently the frequent use of different synthetic compounds like pesticides, herbicides, arsenic, insecticides and fertilizers had led to contamination of environment. Therefore, the current experimental study was conducted to ascertain the concurrent impacts of sodium arsenate and diammonium phosphate in commercial layer. For this purpose a total of 90, day old Lohmann Selected White leghorn chicks of similar weight and sex were procured and kept into six groups. Sodium arsenate and DAP were administered to experimental birds in groups (B-F) alone and in different combination. Group A was kept as control group. Various clinical and behavioral alterations such as watery droppings, dullness, gasping, depression, tremors, anemic comb and wattle were evident in birds. The body weight and relative weight of different organs was reduced significantly. Extensive fatty infiltration, pyknosis of hepatocyte and coagulative necrosis in liver, increased urinary space, necrosis of tubular epithelial cells and congestion in kidneys was observed. The total erythrocytes counts, hemoglobin concentration, hematocrit, mean corpuscular volume and mean corpuscular hemoglobin concentration were significantly reduced. The plasma proteins, serum total proteins, albumin and globulins levels were significantly decreased while serum creatinine and different enzymes were significantly increased in birds. The incidence of erythrocyte with micronucleus, blebbed nucleus and binucleated erythrocyte was significantly increased at different experimental days. In conclusion the arsenic (25 mg/kg bw) and DAP (10%) alone and in combinations (15 mg/kg bw arsenic +6% DAP) were the most toxic to birds. [ABSTRACT FROM AUTHOR]