Showing papers in "Bulletin of Environmental Contamination and Toxicology in 2018"
TL;DR: Investigating translocation and accumulation of cadmium from the soil into 11 native plants showed Carduus nutans and Phlomis could be potentially bioaccumulator plants useful for phytoremediation of mining soils contaminated by Cd.
Abstract: The Gumuskoy mining area is located about 25 km west of Kutahya and is the largest silver deposit in Turkey. The present study investigated translocation and accumulation of cadmium (Cd) from the soil into 11 native plants. Plant and soil samples were collected from the field, and Cd concentrations were analyzed by inductively coupled plasma mass spectroscopy. Mean Cd values in the soil, root, and shoot of native plants in the study area were 82.8 ± 5, 55.4 ± 6, and 43.5 ± 4 mg kg- 1, respectively. Plants were separated into several groups according to the enrichment coefficients for shoot and root values of plants. These groups showed Carduus nutans and Phlomis could be potentially bioaccumulator plants useful for phytoremediation of mining soils contaminated by Cd.
83 citations
TL;DR: Many heavy metals pose a high potential ecological risk on the agricultural soil in these three mining areas in the Xunyang County, and may cause elevated heavy metal contents in crops, eventually jeopardizing the health of local residents who consume food grown in polluted soil.
Abstract: Mining is considered to be one of the most significant sources of environmental pollution with regard to heavy metals. Mineral mining causes large quantities of mercury, cadmium, and other elements to be released into the environment and naturally poses a serious threat to environment. This paper will analyze the pollution status of agricultural soil caused by the mining of heavy metals in various mining areas in the Xunyang County in the Shaanxi Province of China, an area in famous for its resource mining. Equally, it will look at the potential ecological risk assessment process that is used to analyze the ecological risks of mining heavy metals in agricultural soil located in the surrounding areas. Based on the soil investigation, As pose a moderate ecological risk on the Au mining area. In addition, the Hg metals pose a significantly high potential ecological risk and Cd metals pose a considerable potential ecological risk on the Hg mining area. In the Pb-Zn mining area, a significantly high potential ecological risk was mainly posed by Cd. These results suggest that many heavy metals pose a high potential ecological risk on the agricultural soil in these three mining areas in the Xunyang County, and may cause elevated heavy metal contents in crops, eventually jeopardizing the health of local residents who consume food grown in polluted soil.
57 citations
TL;DR: There was no potential exposure of toxicity in buffaloes of the study area and the mean concentration values of Co, Zn, Fe, Cd, Se and As were lower while Cu and Cr were higher than the recommended concentrations.
Abstract: This study was conducted to determine the concentration of toxic metals in soil, forage and blood plasma of lactating and non-lactating buffaloes in the district Jhang, Punjab, Pakistan. Soil samples were collected from varying distances from the road side. Plasma separation was achieved by centrifugation. The concentration of arsenic (As), selenium (Se), cadmium (Cd), chromium (Cr), iron (Fe), zinc (Zn), copper (Cu) and cobalt (Co) were determined by using Atomic Absorption Spectrophotometer. The results of the study showed that the mean As, Se and Cd concentrations in soil samples were lower while Cr, Fe, Zn, Cu and Co were higher than the official guidelines. In plasma samples, mean concentration values of Co, Zn, Fe, Cd, Se and As were lower while Cu and Cr were higher than the recommended concentrations. According to the results of the study there was no potential exposure of toxicity in buffaloes of the study area.
54 citations
TL;DR: The LC50 confirms that nitrite is more toxic than ammonia and nitrate in low salinity waters, and that its toxicity increases with a decrease in salinity.
Abstract: Shrimp farming in low salinities waters is an alternative to increasing production, and counteracting disease problems in brackish and marine waters. However, in low-salinity waters, toxicity of nitrogen compounds increases, and there is no available data of its acute toxicity in shrimp postlarvae. This study determined the acute toxicity of ammonia, nitrite and nitrate in Litopenaeus vannamei postlarvae in 1 and 3 g/L salinity, as well as the safety levels. The LC50 confirms that nitrite is more toxic than ammonia and nitrate in low salinity waters, and that its toxicity increases with a decrease in salinity. The safe levels estimated for salinities of 1 and 3 g/L were 0.54 and 0.81 mg/L for total ammonia–N, 0.17 and 0.25 mg/L for NO2–N, and 5.6 and 21.5 mg/L for NO3–N, respectively.
54 citations
TL;DR: This review will highlight the uncertainties and known effects of DOM on subsequent photoreactions that lead to the occurrence of mercury photodemethylation and reduction in mercury bioavailability in freshwater ecosystems.
Abstract: Mercury contamination is a growing concern for freshwater food webs in ecosystems without point sources of mercury. Methylmercury (MeHg) is of particular concern, as this is the form of mercury that crosses the blood-brain barrier and is neurotoxic to organisms. Wetlands and benthic sediments have high organic content and low oxygen availability. Anaerobic bacteria drive the metabolic function in these ecosystems and subsequently can methylate mercury. The bioavailability of MeHg is controlled by physicochemical characteristics such as pH, binding affinities, and dissolved organic matter (DOM). Similarly, photodemethylation is influenced by similar characteristics and thereby the two processes should be studied in tandem. The degradation of MeHg through photochemistry is an effective destruction mechanism in freshwater lakes. This review will highlight the uncertainties and known effects of DOM on subsequent photoreactions that lead to the occurrence of mercury photodemethylation and reduction in mercury bioavailability in freshwater ecosystems.
47 citations
TL;DR: Among all amendments, BC incorporation into co-contaminated soil offered promising results for Pb and Cd immobilization and could deserve advance monitoring studies on a field scale.
Abstract: A variety of remediation approaches have been applied to the heavy metals-contaminated soils, however, the immobilization of metals in co-contaminated soils still not cleared. Therefore, an incubation study was conducted to evaluate the instantaneous effects of different concentrations of biochar (BC), slag (SL) and Fe–Mn ore (FMO) on immobilization of Pb and Cd through the Toxicity Characteristic Leaching Procedure (TCLP) by following the the European Community Bureau of Reference (BCR), CaCl2 and NH4NO3. The sequential extraction of BCR showed decrease in acid soluble fractions, while the residual proportions of Pb and Cd were enhanced with increasing concentrations of SL and BC. Addition of BC significantly lowered the extractable fractions of both metals by TCLP, NH4NO3 and CaCl2 as compared to SL and FMO. Among all amendments, BC incorporation into co-contaminated soil offered promising results for Pb and Cd immobilization. Overall, all amendments showed positive and long-term impact on the reclamation of co-contaminated soil with heavy metals and could deserve advance monitoring studies on a field scale.
47 citations
TL;DR: The effect of soil composition on the reduction of hexavalent chromium (Cr(VI) by zero valent iron nanoparticles was studied and the proposed model was validated through experimental tests performed on soil samples collected at an industrial polluted site, and on artificially contaminated samples from the same site, in the presence of selected amount of leonardite.
Abstract: The effect of soil composition on the reduction of hexavalent chromium (Cr(VI)) by zero valent iron nanoparticles was studied. A model was proposed, to investigate both the effect of manganese oxide and the simultaneous effect of manganese dioxide and soil organic matter on the kinetic of Cr(VI) reduction. Fe(0) nanoparticles consumption by the reaction with dissolved oxygen, water and soluble Cr(VI) was taken into account. The model was validated through experimental tests performed on soil samples collected at an industrial polluted site, and on artificially contaminated samples from the same site, in the presence of selected amount of leonardite.
46 citations
TL;DR: RSB demonstrated positive results as soil amendments for Cd immobilization, increasing soil nutrient availability, and enhancing soil microbial biomass.
Abstract: Biochar is considered a novel soil amendment to reduce metal mobility, but its influence on soil chemical and biochemical properties is not fully understood. In the present study, biochar derived from rice straw (RSB), rice hull (RHB), and maize stover (MSB) was used to evaluate comparative efficiency on Cd mobility and soil biochemical properties. Ammonium nitrate extractable Cd significantly decreased among all the applied biochar types and application rates. The European Community Bureau of Reference (BCR) technique showed significant decrease in acid-soluble Cd by 24%-32%, 19%-23%, and 22%-27% for RSB, RHB, and MSB, respectively at the 1.5% and 3% rate. However, the concentration of Cd in the residual increased by 38%, 35% and 36% for RSB, RHB and MSB, respectively at a 3% application rate. Soil microbial biomass (C and N) and inorganic nitrogen forms (NH4 and NO3) significantly increased among all biochar applications. Overall, RSB demonstrated positive results as soil amendments for Cd immobilization, increasing soil nutrient availability, and enhancing soil microbial biomass.
45 citations
TL;DR: An incubation study was conducted to assess the effectiveness of biochar, zeolite and rock phosphate stabilizers on the immobilization of cadmium (Cd) in contaminated soils and found that BC offered better results when compared to other amendments.
Abstract: Heavy metal contamination in agricultural soils has become a serious environmental concern due to their generally high mobility and toxic effects on plants and food security. An incubation study was conducted to assess the effectiveness of biochar (BC), zeolite (ZE) and rock phosphate (RP) stabilizers on the immobilization of cadmium (Cd) in contaminated soils. Various extraction techniques were carried out: a sequential extraction procedure, the European Community Bureau of Reference (BCR), the toxicity characteristics leaching procedure (TCLP) and extraction with ammonium nitrate. In addition, Cd adsorption by these materials was observed using Langmuir and Freundlich isotherms. The results showed that with an increase in soil pH the exchangeable fraction of Cd in soil was significantly reduced by 28%–29.4%, 9%–13% and 4%–14% for BC, ZE, and RP, respectively. According to the Langmuir adsorption isotherm, BC-amended soil showed a higher adsorption capacity (Qm) of Cd from 8.38 to 19.85 mg g−1. Overall, BC offered better results when compared to other amendments.
44 citations
TL;DR: It was concluded that trace metal and metalloid accumulation was a major health concern for the public consuming these vegetables.
Abstract: This study focused on evaluating the metal and metalloid contamination and associated risks in the two vegetables crops, coriander (Coriandrum sativum) and spinach (Spinacia oleracea) treated with three water regimes, canal water, groundwater and municipal wastewater. These vegetables are widely consumed by people and are also used in traditional medicine for treating various disorders. Metal and metalloid accumulation (Zn, Pb, Se, Cu, As, Mo, Fe, Ni) was found higher in vegetables treated with wastewater. Wastewater treated soil had high pollution load index. Fe, Zn, As and Pb had higher values in water, soil and vegetables as compared to other studied metals. Overall, metal correlation for soil and vegetables was significant and positive except for Fe and Cu in spinach. The highest value for daily metal intake was estimated for Fe while Se had the lowest value for the same index. It was thus concluded that trace metal and metalloid accumulation was a major health concern for the public consuming these vegetables.
44 citations
TL;DR: Single particle inductively coupled plasma mass spectrometry was used to detect Ti-containing particles in heavily-used bathing areas of a river and five swimming pools, showing morphological similarity to particles present in an over-the-counter sunscreen product.
Abstract: Single particle inductively coupled plasma mass spectrometry (spICP-MS) was used to detect Ti-containing particles in heavily-used bathing areas of a river (Salt River) and five swimming pools. Ti-containing particle concentrations in swimming pools ranged from 2.8 × 103 to 4.4 × 103 particles/mL and were an order of magnitude lower than those detected in the Salt River. Measurements from the Salt River showed an 80% increase in Ti-containing particle concentration over baseline concentration during peak recreational activity (at 16:00 h) in the river. Cloud point extraction followed by transmission electron microscopy with energy dispersive X-ray analysis confirmed presence of aggregated TiO2 particles in river samples, showing morphological similarity to particles present in an over-the-counter sunscreen product. The maximum particle mass concentration detected in a sample from the Salt River (659 ng/L) is only slightly lower than the predicted no effect concentration for TiO2 to aquatic organisms (< 1 μg/L).
TL;DR: Along with inhibition in root length and protein content, depression in mitotic index as well as stimulation of various abnormality in Mitotic cell division indicated that both metal(loid) are hazardous in nature and causing harmful effect on the environment.
Abstract: A study was performed for phyto-genotoxic assay of chromium (Cr) and arsenic (As) through Allium cepa. Various concentrations (0, 1, 3, 6 and 12 mg L−1) of Cr and As for 48 and 168 h time points exposed to A. cepa. The phytotoxic effects of metal(loid) were evident through inhibited root length and root protein. Metal(loid) toxicity also lead to genotoxic effects, which included depression of mitotic index and increased frequency of chromosomes aberrations like break, fragments, c-metaphase, multipolar arrangements etc. Genotoxic endpoint as progressive frequency of micronuclei in interphase of root meristem cells in treated plants was also observed. This genotoxic endpoint revealed carcinogenic nature of both aforementioned metal(loid). Along with inhibition in root length and protein content, depression in mitotic index as well as stimulation of various abnormality in mitotic cell division indicated that both metal(loid) are hazardous in nature and causing harmful effect on the environment.
TL;DR: Production, chemistry, and few data on toxicity to aquatic species suggest that un-weathered dilbit would cause effects on fish equivalent to those of conventional oils, but its toxicity may be lower, depending on interactions among test conditions, the behavior of dilbit added to water and the species tested.
Abstract: Canada has experienced a significant increase in the transport of diluted bitumen (dilbit), a predominant oil sands product that combines bitumen with diluents derived from oil–gas condensates and other proprietary compounds. The proportion of diluent and the chemical composition of dilbit vary to meet seasonal transport requirements. While the toxic effects of a variety of crude and refined oils are well-studied, the toxicity of dilbit to aquatic species is less well known. This focused review summarizes dilbit production, chemistry, and the few data on toxicity to aquatic species. These data suggest that un-weathered dilbit would cause effects on fish equivalent to those of conventional oils, but its toxicity may be lower, depending on interactions among test conditions, the behavior of dilbit added to water and the species tested.
TL;DR: Significant correlations between OC and EC, and OC/EC ratio suggested that vehicular emissions, fossil fuel combustion and biomass burning could be major sources of carbonaceous aerosols of PM2.5 at the sampling site of Delhi, India.
Abstract: Organic carbon (OC) and elemental carbon (EC) in PM2.5 were estimated to study the seasonal and inter-annual variability of atmospheric total carbonaceous aerosols (TCA) at an urban site of megacity Delhi, India for 5 years from January, 2012 to December, 2016. The annual average (± standard deviation) concentrations of PM2.5, OC, EC and TCA were 128 ± 81, 16.6 ± 12.2, 8.4 ± 5.8 and 34.5 ± 25.2 µg m-3, respectively. During the study, significant seasonal variations in mass concentrations of PM2.5, OC, EC and TCA were observed with maxima in winter and minima in monsoon seasons. Significant correlations between OC and EC, and OC/EC ratio suggested that vehicular emissions, fossil fuel combustion and biomass burning could be major sources of carbonaceous aerosols of PM2.5 at the sampling site of Delhi, India.
TL;DR: The results demonstrated that agricultural herbicides were detected in all water samples, including tap, surface and groundwater samples, and since the residues are generally below the safe limits established by the government authorities, the monitored 11 herbicides do not significantly affect the quality of the human environment.
Abstract: This work investigated drinking water contamination by 11 commonly used herbicides in sugarcane production areas in Guangxi, China. The work developed an analytical method for determination of these herbicides in environmental waters. This work studied herbicide residues in drinking water in Guangxi, China. The maximum residues and percent of detects were: (0.091 µg/L, 29.2%, atrazine), (0.018 µg/L, 8.3%, ametryne), (0.188 µg/L, 8.3%, aetolaehlor), (0.139 µg/L, 4%, simazine), (0.585 µg/L, 62.5%, atrazine), (0.311 µg/L, 33.3%, acetochlor), (0.341 µg/L, 58.3%, ametryne), (1.312 µg/L, 29.2%, metolachlor), (0.088 µg/L, 4.2%, alachlor), (0.127 µg/L, 14.3%, atrazine), and (0.453 µg/L, 7.1%, metolachlor), respectively. The results demonstrated that agricultural herbicides were detected in all water samples, including tap, surface and groundwater samples. Since the residues are generally below the safe limits established by the government authorities, the monitored 11 herbicides do not significantly affect the quality of the human environment. This work will provide scientific understanding of pesticide residues in drinking water standards in terms of its consistency with precautionary human health and environmental safety.
TL;DR: It is suggested that herbicide-induced alterations of soil microorganisms could have knock-on effects on other parts of the grapevine system.
Abstract: In a vineyard we examined the effects of broad-spectrum herbicides with three different active ingredients (glyphosate, glufosinate, flazasulfuron) on soil microorganisms Mechanical weeding served as control treatment Treatments were applied within grapevine rows and soil samples taken from there in 10–20 cm depth 77 days after application Fungi were analyzed using classical sequencing technology and bacteria using next-generation sequencing The number of colony-forming units (CFU) comprising bacteria, yeasts and molds was higher under flazasulfuron compared to all other treatments which had similar CFU levels Abundance of the fungus Mucor was higher under flazasulfuron than glufosinate and mechanical weeding; Mucor was absent under glyphosate Several other fungi taxa were exclusively found under a specific treatment Up to 160 different bacteria species were found – some of them for the first time in vineyard soils Total bacterial counts under herbicides were on average 260% higher than under mechanical weeding; however due to high variability this was not statistically significant We suggest that herbicide-induced alterations of soil microorganisms could have knock-on effects on other parts of the grapevine system
TL;DR: The bioaccumulation factor and translocation factor calculated for metal accumulation analysis in cotton plant parts were found to be above 1 which indicated that the cotton plant can prove to be a significant system for phytoremediation and an efficient green tool for decontamination of soils from heavy metals.
Abstract: Phytoremediation, a technique dependent on the heavy metal bioaccumulation and translocation in different parts of plants, is an efficient and environment friendly method for decontamination of soils from metals. In the present study, the bioaccumulation and translocation of heavy metals was analyzed in different parts of cotton plant grown in intensively cultivated agricultural fields of Malwa region of Punjab, India. The soils were found to be alkaline in nature with very high sand contents which resulted in low retention of metals (As, Cr, Cu, Mn, Sr and Zn) in soils. But, the bioaccumulation factor and translocation factor calculated for metal accumulation analysis in cotton plant parts were found to be above 1 (maximum 9.13 for Sr) which indicated that the cotton plant (a non-edible fibre crop) can prove to be a significant system for phytoremediation and an efficient green tool for decontamination of soils from heavy metals.
TL;DR: Results show that short-term exposures to environmentally relevant concentrations of IMI could affect the genetic integrity of fishes through oxidative damage.
Abstract: Neonicotinoids are one of the most widely used insecticides in the world. DNA damage is considered an early biological effect which could lead to reproductive and carcinogenic effects. The present study aimed to evaluate DNA damage and bases oxidation as a mechanism of genotoxicity, on the freshwater fish Australoheros facetus acutely exposed to imidacloprid (IMI). The Comet assay with the nuclease ENDO III enzyme was performed for detecting pyrimidine bases oxidation using blood samples. Micronucleus and other nuclear abnormalities frequencies were also quantified. A significant increase of damage index at 100 and 1000 µg/L IMI was detected; while ENDO III score increased from 1 to 1000 µg/L IMI; varying both in a linear concentration-response manner. MN frequency increased in fish exposed to 1000 µg/L IMI. These results show that short-term exposures to environmentally relevant concentrations of IMI could affect the genetic integrity of fishes through oxidative damage.
TL;DR: This article showed that wheat can tolerate Cd by enhancing the antioxidant enzymes activities and increasing the concentration of ascorbate and glutathione, suggesting that the Cd application promoted nitrogen metabolism over carbon metabolism.
Abstract: Wheat (Triticum aestivum L.) has relatively high tolerance to cadmium (Cd), but the underlying mechanisms are poorly understood. Growth and physiological parameters of wheat exposed to different Cd concentrations (0, 0.5, 5 and 50 µM) were characterized. The fresh weight, leaf chlorophyll and carotenoid concentrations and photosynthesis parameters did not differ among Cd treatments, suggesting relatively high Cd tolerance in wheat. However, the soluble sugar concentrations increased with the increasing Cd concentration and the soluble protein concentrations decreased in both shoots and roots, suggesting that the Cd application promoted nitrogen metabolism over carbon metabolism. In addition, the higher concentrations of MDA, GSH and AsA and activities of antioxidant enzymes (SOD, POD, and CAT) were observed in leaves and roots in the Cd50 treatment. Our results reveal that wheat can tolerate Cd by enhancing the antioxidant enzymes activities and increasing the concentration of ascorbate and glutathione.
TL;DR: Among all the plants studied, Calotropis procera accumulated the highest level of Pb; Thus, it can be used as good biomonitor/phytoremediator at Pb contaminated areas.
Abstract: This study assessed the level of Pb in soil and five wild plant species (Calotropis procera, Datura alba, Parthenium hysterophorus, Cenchrus ciliaris and Ricinus communis) during all the four seasons. Two busy roads varying in age and traffic volume were selected i.e., Faisalabad-Sargodha road (FSR) and Pindi Bhattian to Lillah (M-2) in the Punjab, Pakistan. Results showed raised levels of Pb in both plants and soil samples along both roads. The range of Pb concentration in plants was 0.08-3.98 and 1.95-4.74 mg kg- 1 for soil. Higher Pb contamination was recorded along FSR road as compared to M-2. Among seasons, the higher Pb concentration was found during summer, probably due to very high temperature. Among all the plants studied, Calotropis procera accumulated the highest level (3.98 mg kg- 1 dry wt.) of Pb; Thus, it can be used as good biomonitor/phytoremediator at Pb contaminated areas.
TL;DR: The highest correlations were found for < 28 µm and heavy metals followed by 150–300 ´m fraction which are susceptible to wind erosion risk in an arid environment.
Abstract: This study was conducted to explore the relationships between magnetic susceptibility and some soil heavy metals concentrations in various particle sizes in an industrial site, central Iran. Soils were partitioned into five fractions (< 28, 28–75, 75–150, 150–300, and 300–2000 µm). Heavy metals concentrations including Zn, Pb, Fe, Cu, Ni and Mn and magnetic susceptibility were determined in bulk soil samples and all fractions in 60 soil samples collected from the depth of 0–5 cm. The studied heavy metals except for Pb and Fe displayed a substantial enrichment in the < 28 µm. These two elements seemed to be independent of the selected size fractions. Magnetic minerals are specially linked with medium size fractions including 28–75, 75–150 and 150–300 µm. The highest correlations were found for < 28 µm and heavy metals followed by 150–300 µm fraction which are susceptible to wind erosion risk in an arid environment.
TL;DR: Of all the plant seeds under study, the most sensitive to the presence of the examined metals during germination were the seeds of cress, rye, rye and barley, while vetch and eight plant species of major importance to human consumption were found to be least affected.
Abstract: Laboratory experiments were conducted to assess the effects of highly toxic and dangerous metals (Pb, Cd, Hg) and essential microelements (Cr, Cu, Ni, Zn) on the seed germination process in vetch and eight plant species of major importance to human consumption. The degree of metal toxicity was determined on the basis of acute LC50 values calculated by means of two different methods. All the metals were found to inhibit the germination process, but in a varying, species-dependent degree. Of all the plant seeds under study, the most sensitive to the presence of the examined metals during germination were the seeds of cress (Cu, Pb, Hg), rye (Ni, Zn, Cd) and barley (Cr), while vetch (Cr, Ni, Zn, Cd, Pb, Hg), rape (Cr, Cu) and pea (Ni, Cd) were found to be least affected.
TL;DR: Detailed studies examining changes in nutrient and total suspended solid concentrations and loads associated with management practices in drainage ditches with emphasis on the Lower Mississippi Alluvial Valley and identified information gaps regarding water quality are summarized.
Abstract: Agricultural non-point sources of nutrients and sediments have caused eutrophication and other water quality issues in aquatic and marine ecosystems, such as the annual occurrence of hypoxia in the Gulf of Mexico. Management practices have been implemented adjacent to and in agricultural drainage ditches to promote their wetland characteristics and functions, including reduction of nitrogen, phosphorus, and sediment losses downstream. This review: (1) summarized studies examining changes in nutrient and total suspended solid concentrations and loads associated with management practices in drainage ditches (i.e., riser and slotted pipes, two-stage ditches, vegetated ditches, low-grade weirs, and organic carbon amendments) with emphasis on the Lower Mississippi Alluvial Valley, (2) quantified management system effects on nutrient and total suspended solid concentrations and loads and, (3) identified information gaps regarding water quality associated with these management practices and research needs in this area. In general, management practices used in drainage ditches at times reduced losses of total suspended solids, N, and P. However, management practices were often ineffective during storm events that were uncommon and intense in duration and volume, although these types of events could increase in frequency and intensity with climate change. Studies on combined effects of management practices on drainage ditch water quality, along with research towards improved nutrient and sediment reduction efficiency during intense storm events are urgently needed.
TL;DR: Clothianidin leaching was minimized in soil of Manipur compared to Delhi after incorporation of FYM, and mobility can be reduced by organic amendment application as the volume of water increased upto 160 mL, mobility increased and residues moved to lower depth.
Abstract: Clothianidin is a widely used insecticide under Indian subtropical condition. The objective of this study was to generate residue data which aims to understand leaching potential of clothianidin [(E)-1-(2-chloro-1,3-thiazol-5-ylmethyl)-3-methyl-2- nitroguanidine] through packed soil column. The maximum amount of clothianidin was recovered at 0–5 cm soil depth in both Manipur (67.15%) and Delhi soil (52.0%) under continuous flow condition. Manipur and Delhi soil concentrated maximum residue with or without farm yard manure (FYM) in 0–20 cm soil depth. The effect of varying the amount of water enhanced the distribution of residues in the first 0–5 cm layer. Among the tested soils, residue was detected in the leachate from Delhi soil (0.04 µg/mL). Clothianidin leaching was minimized in soil of Manipur compared to Delhi after incorporation of FYM. As the volume of water increased upto 160 mL, mobility increased and residues moved to lower depth. Clothianidin did not leach out of the 25 cm long soil columns even after percolating water equivalent to 415.42 mm rainfall. Clothianidin is mobile in soil system and mobility can be reduced by organic amendment application.
TL;DR: It is demonstrated that chronic PFOS exposure altered thyroid hormone level, thyroid follicular cell structure and thyroid hormone related gene expression, suggesting the validity of zebrafish as an alternative model for PFOS chronic toxicity screening.
Abstract: Perfluorooctane sulfonic acid (PFOS), as a potential endocrine disrupting chemical, is widely detected in the environment, wildlife and human. Currently few studies have documented the effects of chronic PFOS exposure on thyroid in aquatic organisms and the underlying mechanisms are largely unknown. The present study assessed the effect of chronic PFOS exposure on thyroid structure and function using zebrafish model. Zebrafish at 8 h post fertilization (hpf) were exposed to PFOS (250 µg/l) until 120 d post fertilization (dpf). Thyroid hormone (T3 and T4) level, thyroid morphology and thyroid function related gene expression were evaluated in zebrafish at 120 dpf. Our findings demonstrated that chronic PFOS exposure altered thyroid hormone level, thyroid follicular cell structure and thyroid hormone related gene expression, suggesting the validity of zebrafish as an alternative model for PFOS chronic toxicity screening.
TL;DR: The biomass as well as the relative growth rate has increased with the amount of cobalt in wastewaters, the plant manifesting an excellent tolerance to cobalt exposure, and E. canadensis’ hyperaccumulator character with regard to Cobalt is emphasised.
Abstract: Present paper investigates the phytoremediation of cobalt from wastewaters using Elodea canadensis. Bioaccumulation tests were conducted at various concentrations of cobalt ranging from 1 to 15 mg/L. Final concentrations of cobalt in wastewaters, after phytoremediation, were less than 1 mg/L. E. canadensis’ hyperaccumulator character with regard to cobalt is emphasised by the amount of cobalt retained: 0.39% ± 0.02% of dry mass at an initial concentration in wastewater of 15 mg/L. After 14 days of exposure to contaminant, the biomass as well as the relative growth rate has increased with the amount of cobalt in wastewaters, the plant manifesting an excellent tolerance to cobalt exposure. Adsorption of cobalt ions by E. canadensis can be well described by the Langmuir adsorption isotherm and the pseudo-second-order model equation.
TL;DR: The results indicate that Tolypocladium geodes and Cordyceps cicadae might be used in acetochlor bioremediation with a significant acetchlor, COD, TOC and BOD5 reduction and can be used for rehabilitation of agricultural fields or receiving environments for removal the opposite effects of acetochchlor or other herbicides.
Abstract: In this study, we aimed to find out the biodegradation efficiency of some soil fungi types on herbicide acetochlor with acetochlor active material, chemical oxygen demand (COD), biochemical oxygen demand (BOD5) and total organic carbon (TOC) parameters. We also try to determine the population dynamics of these fungi via turbidity. The fungi cultures were isolated from agricultural field in in Thrace region of Turkey. Each fungi enriched in malt extract broth media and 1 mL of these enriched media was inoculated into 100 mL of acetochlor solutions that suggested for using application concantrations in agricultural field for farmers (11000 mg L-1) for sunflower and corn agriculture. Bioremediation results of acetochlor have shown different results according to the types of fungi. Our results indicate that Tolypocladium geodes and Cordyceps cicadae might be used in acetochlor bioremediation with a significant acetochlor, COD, TOC and BOD5 reduction and can be used for rehabilitation of agricultural fields or receiving environments for removal the opposite effects of acetochlor or other herbicides.
TL;DR: The results indicate that B stress inhibits root and shoot growth of wheat in a concentration-dependent manner, and leads to increases in TBARS and H2O2 contents in shoot tissue, and suggest that high concentrations of B may exert a genotoxic effect on wheat.
Abstract: Boron (B) toxicity, which occurs in semi-arid and arid environments, can adversely affect the growth and yield of many plants. The aim of this study was to determine the effects of different concentrations of boric acid (3, 6, 9 and 12 mM) on growth, oxidative stress and genotoxicity parameters in root and shoot tissues of wheat seedlings. Our results indicate that B stress inhibits root and shoot growth of wheat in a concentration-dependent manner, and leads to increases in TBARS and H2O2 contents in shoot tissue. Moreover, our findings suggest that high concentrations of B may exert a genotoxic effect on wheat. To the best of our knowledge, this is the first report to evaluate the effect of B stress on genotoxicity in both root and shoot tissues of wheat.
TL;DR: In this article, the effects of nano-hydroxyapatite (n-HA) and it combined with lime, zeolite, bone mill and fly ash on Cd immobilization in soils and uptake in potatoes, were investigated in a contaminated soil by pot experiments.
Abstract: The toxicity of cadmium (Cd) has posed major public health concern in crops grown in the Cd-contaminated soils. The effects of five amendments, nano-hydroxyapatite (n-HA) and it combined with lime, zeolite, bone mill and fly ash on Cd immobilization in soils and uptake in potatoes, were investigated in a contaminated soil by pot experiments. The result showed that the applications of combined amendments significantly decreased the bioavailable Cd concentrations extracted by TCLP, DTPA–TEA and MgCl2 in the contaminated soils, and changed the soluble and exchangeable and specifically sorbed fractions to oxide-bound and organic-bound fractions. Compared to the control group, the concentrations of Cd in the potato tubers grown in n-HA, n-HA + Fly ash, n-HA + Lime, n-HA + Bone mill and n-HA + Zeolite soil were reduced 17.4%, 20.7%, 15.2%, 32.6% and 39.1%, respectively. Nano-hydroxyapatite combined amendments was more effective in reducing bioavailable Cd concentrations and Cd accumulations in potatoes, especially for n-HA + Z.
TL;DR: The youngest shark showed higher concentrations of ΣDDTs in the liver than the older sharks, and female sharks showed the highest concentrations, in one of the few investigations on DDT levels in S. microcephalus where concentrations were correlated to lipid content and sex/size.
Abstract: DDT isomers were detected in all the liver and muscle samples of Greenland sharks Somniosus microcephalus (n = 15) caught in Greenland seawaters. The mean concentrations of ΣDDTs (sum of o,p’ and p,p’ DDT, DDD, and DDE isomers) were 1094 ± 818 ng/g lipid weight (lw) in the muscle and 761 ± 416 ng/g lw in the liver. The p,p’-DDE accounted for 48% ± 41% and 53% ± 54% of the total DDT residue in the white muscle and liver, respectively. The lipid content was 48% ± 10% in the muscle and 43% ± 17% in the liver. Female sharks showed the highest concentrations of ΣDDTs. The youngest shark showed higher concentrations of ΣDDTs in the liver than the older sharks. To our knowledge, this is one of the few investigations on DDT levels in S. microcephalus where concentrations were correlated to lipid content and sex/size.