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Dynamics in imidacloprid sorption related to changes of soil organic matter content and quality along a 20-year cultivation chronosequence of citrus orchards Full text
2021
Zheng, Taihui | Hu, Tong | Zhang, Jie | Tang, Chongjun | Duan, Jian | Song, Yuejun | Zhang, Qin
The on-going and extensive use of neonicotinoids occur in orchards. However, it is still unknown whether and how orchard management affects soil properties, especially the contents and structure of soil organic matter during orchard development, and their further influences on neonicotinoid persistence. Here, surface soil samples were collected from the citrus orchards with different cultivation ages (1, 10, 14, and 20 years), and their physicochemical properties were determined. Changes in the chemical structure of soil organic matter (SOM) were furtherly examined using solid-state CP/TOSS ¹³C NMR. Then, the sorption isotherms of imidacloprid in these soils were investigated. The sorption coefficient (Kd) of imidacloprid at Cₑ of 0.05 mg/L in the orchard soils increased by 19.4–23.3%, along a 20-year chronosequence of cultivation, which should be mainly ascribed to the increase of SOM. However, the organic carbon-normalized sorption coefficient (Kₒc, sorption per unit mass of OM) of imidacloprid declined with increasing cultivation ages. Moreover, the polar and aliphatic domains of SOM had a significantly positive relation to the Kₒc of imidacloprid, suggesting its key role in governing imidacloprid sorption. The results highlighted that reasonable management measures could be adopted to control the occurrence and fate of neonicotinoids in soils, mainly by affecting the content and quality of SOM.
Show more [+] Less [-]Pentachlorophenol and ciprofloxacin present dissimilar joint toxicities with carbon nanotubes to Bacillus subtilis Full text
2021
Deng, Rui | Yang, Kun | Lin, Daohui
Discharged carbon nanotubes (CNTs) likely interact with co-existing organic contaminants (OCs) and pose joint toxicity to environmental microbes. Herein, hydrophobic pentachlorophenol (PCP) and hydrophilic ciprofloxacin (CIP) were used as representative OCs and their joint toxicities with CNTs to Bacillus subtilis were systematically investigated at cellular, biochemical, and omics levels. The 3-h bacterial growth half inhibitory concentrations of CNTs, PCP, and CIP were 12.5 ± 2.6, 3.5 ± 0.5, and 0.46 ± 0.03 mg/L, respectively, and they all could damage cell membrane, increase intracellular oxidative stress, and alter bacterial metabolomics and transcriptomics; while CNTs-PCP and CNTs-CIP binary exposures exhibited distinct additive and synergistic toxicities, respectively. CNTs increased bacterial bioaccumulation of PCP and CIP via destabilizing and damaging cell membrane. PCP reduced the bioaccumulation of CNTs, while CIP had no significant effect; this difference could be owing to the different effects of the two OCs on cell-surface hydrophobicity and CNTs electronegativity. The additive toxicity outcome upon CNTs-PCP co-exposure could be a result of the balance between the increased toxicity from increased PCP bioaccumulation and the decreased toxicity from decreased CNTs bioaccumulation. The increased bioaccumulation of CIP contributed to the synergistic toxicity upon CNTs-CIP co-exposure, as confirmed by the increased inhibition of topoisomerase Ⅳ activity and interference in gene expressions regulating ABC transporters and lysine biosynthesis. The findings provide novel insights into environmental risks of CNTs.
Show more [+] Less [-]Organic stimulants for enhancing phytoremediation of crude oil polluted soil: A study on cowpea Full text
2021
Aliku, Chioma Bella | Madu, Christian N. | Aliku, OrevaOghene
Petroleum hydrocarbon (PH) contamination of soils remains a major threat to environmental health and food security. A two-years phytoremediation study was conducted on a crude oil polluted soil to assess changes in soil total petroleum hydrocarbon concentration (TPHₛₒᵢₗ) following use of pawpaw seed powder (PSP), moringa seed powder (MSP) and their combination (PSP + MSP) as organic stimulants in cowpea cultivation. The stimulants were tested at different application rates (100, 150, 200 and 250 g m⁻²), with the control (No stimulant) for their effectiveness in reducing TPHₛₒᵢₗ and accelerating the removal rate (R) of PH from soil. The TPHₛₒᵢₗ did not differ significantly (p < 0.05) among the treatments in year 1, but was highest in the control (11,600 mg kg⁻¹) and least in 200 g m⁻² PSP (7400.0 mg kg⁻¹). In year 2, mean TPHₛₒᵢₗ varied significantly (p < 0.05) and remained highest in control (7100 mg kg⁻¹) but lowest in 150 g m⁻² PSP (2700 mg kg⁻¹). Application of 150 g m⁻² PSP gave the highest R (78.2%), followed by 150 g m⁻² PSP+MSP (77.4%), and least by the control (42.7%) over two years of study. The average fresh pod yield of cowpea over two years was highest in 250 g m⁻² PSP (2416.67 kg ha⁻¹), followed by 150 g m⁻² PSP (2173.34 kg ha⁻¹) and least in control (1302.22 kg ha⁻¹). There was significant negative association between TPHₛₒᵢₗ and fresh pod yield (r = −0.403; p < 0.01). However, application of 150 g m⁻² PSP appeared most effective for enhanced phytoremediation of crude oil polluted soil and improvement of cowpea yield.
Show more [+] Less [-]Repeated exposure to fungicide tebuconazole alters the degradation characteristics, soil microbial community and functional profiles Full text
2021
Han, Lingxi | Kong, Xiabing | Xu, Min | Nie, Jiyun
Tebuconazole is a broad-spectrum triazole fungicide that has been extensively applied in agriculture, but its toxicity on soil ecology remains unknown after repeated introduction to soil. This study investigated the degradation of tebuconazole and the changes in soil microbial community composition and functional diversity as well as network complexity in soil repeatedly treated with tebuconazole. Tebuconazole degraded slowly as the degradation half-life initially increased and then decreased during the four repeated treatments. High concentration of tebuconazole treatment significantly delayed the degradation of tebuconazole. The soil microbial functional diversity in tebuconazole-treated soils showed an inhibition-recovery-stimulation trend with increasing treatment frequency, which was related to the increased degradation rates of tebuconazole. Tebuconazole significantly decreased soil microbial biomass and bacterial community diversity, and this decreasing trend became more pronounced with increasing treatment frequency and concentration. Moreover, tebuconazole significantly decreased soil bacterial community network complexity, particularly at high concentration of tebuconazole treatment. Notably, four bacterial genera, Methylobacterium, Burkholderia, Hyphomicrobium, and Dermacoccus, were identified as the potential tebuconazole-degrading bacteria, with the relative abundances in the tebuconazole treatment significantly increasing by 42.1–34687.1% compared to the control. High concentration of tebuconazole treatment delayed increases in the relative abundances of Methylobacterium but promoted those of Burkholderia, Hyphomicrobium and Dermacoccus. Additionally, repeated tebuconazole treatments improved only four metabolic pathways, cell motility, membrane transport, environmental information processing, and xenobiotics biodegradation and metabolism, which were associated with the degradation of tebuconazole. The above results indicated that repeated tebuconazole treatments resulted in the significant accumulation of residues and long-term negative effects on soil ecology, and also emphasized the potential roles of dominant indigenous microbial bacteria in the degradation of tebuconazole.
Show more [+] Less [-]Current trends and possibilities for exploitation of Grape pomace as a potential source for value addition Full text
2021
Chowdhary, Pankaj | Gupta, Abhishek | Gnansounou, Edgard | Pandey, Ashok | Chaturvedi, Preeti
Grape pomace (GP) is a low-value by-product that contains a significant amount of high value-added products. The huge amount of non-edible residues of GP wastes (seeds, skins, leaves and, stems) produced by wine industries causes’ environmental pollution, management issues as well as economic loss. Studies over the past 15–20 years revealed that GP could serve as a potential source for valuable bioactive compounds like antioxidants, bioactive, nutraceuticals, single-cell protein, and volatile organic compounds with an increasing scientific interest in their beneficial effects on human and animal health. However, the selection of appropriate techniques for the extraction of these compounds without compromising the stability of the extracted products is still a challenging task for the researcher. Based on the current scenario, the review mainly summarizes the novel applications of winery wastes in many sectors such as agriculture, pharmaceuticals, cosmetics, livestock fields, and also the bio-energy recovery system. We also summarize the existing information/knowledge on several green technologies for the recovery of value-added by-products. For the promotion of many emerging technologies, the entrepreneur should be aware of the opportunities/techniques for the development of high-quality value-added products. Thus, this review presents systematic information on value-added by-products that are used for societal benefits concerning the potential for human health and a sustainable environment.
Show more [+] Less [-]Mediation effects of thyroid function in the associations between phthalate exposure and glucose metabolism in adults Full text
2021
Huang, Han-Bin | Siao, Chi-Ying | Lo, Yuan-Ting C. | Shih, Shu-Fang | Lu, Chieh-Hua | Huang, Po-Chin
The mediating influence of thyroid function on the association of phthalate exposure with glucose metabolism, including insulin resistance, remains unclear. We explored the mediating influence of thyroid hormone levels on the phthalate exposure–insulin resistance association. This cross-sectional study of 217 Taiwanese adults assessed insulin resistance (Homeostatic Model Assessment for Insulin Resistance, HOMA-IR scores) and the levels of 11 urinary phthalate metabolites and 5 thyroid hormones. Multiple regression models were used to analyze the associations among serum thyroid hormone levels, urinary phthalate metabolite levels, and HOMA-IR scores. The mediation analysis assessed the influence of thyroid function on the phthalate exposure–HOMA-IR association. Our data indicated urinary mono-ethylhexyl phthalate (MEHP) levels was negatively associated with free thyroxine (T₄) (β = −0.018; 95% confidence interval [CI]: −0.031, −0.005) and positively associated with HOMA-IR scores (β = 0.051, 95% CI: 0.012, 0.090). The study also revealed urinary mono-(2-ethyl-5-oxohexyl) phthalate (MEOHP) levels was negatively associated with free T₄ (β = −0.036, 95% CI: −0.056, −0.017) and HOMA-IR (β = 0.070, 95% CI: 0.013, 0.126). Free T₄ and HOMA-IR had a negative association (β = −0.757, 95% CI: −1.122, −0.392). In the mediation analysis, free T₄ mediated 24% and 35% of the associations of urinary MEHP and MEOHP with HOMA-IR, respectively. Our findings revealed the mediating role of thyroid function in the phthalate exposure–glucose metabolism association in adults.
Show more [+] Less [-]Hazard evaluation of indoor environment based on long-term pollutant emission characteristics of building insulation materials: An empirical study Full text
2021
Wi, Seunghwan | Kang, Yujin | Yang, Sungwoong | Kim, Young Uk | Kim, Sumin
Insulation materials are essential components in construction, and their main objective is to increase the efficiency of thermal energy by minimizing internal and external thermal exchange. Accordingly, research and development studies are being actively conducted to increase the thermal resistance of insulation materials, and high-performance insulation materials that use organic chemicals have been developed after industrialization. However, thermal insulation comprising chemicals poses a potential risk of pollutant emissions and can cause health problems. In this study, five types of insulation materials and the contaminants generated from the building materials used in insulation construction were quantitatively analyzed. In addition, an empirical study on the discharge of pollutants was conducted using a test bed, and the effects of the pollutants discharged from the insulation material on the indoor environment were examined by analyzing the pollutant concentration for 90 days. In addition, we analyzed the effect of an insulation material on an indoor environment through the standard specifications. Moreover, the necessity of legal management of the emission of contaminants from insulation materials was proposed based on the empirical research results.
Show more [+] Less [-]Fuel consumption and air emissions in one of the world’s largest commercial fisheries Full text
2021
Chassot, Emmanuel | Antoine, Sharif | Guillotreau, Patrice | Lucas, Juliette | Assan, Cindy | Marguerite, Michel | Lamboy, Nathalie Bodin
Fuel consumption and air emissions in one of the world’s largest commercial fisheries Full text
2021
Chassot, Emmanuel | Antoine, Sharif | Guillotreau, Patrice | Lucas, Juliette | Assan, Cindy | Marguerite, Michel | Lamboy, Nathalie Bodin
The little information available on fuel consumption and emissions by high seas tuna fisheries indicates that the global tuna fleet may have consumed about 2.5 Mt of fuel in 2009, resulting in the production of about 9 Mt of CO₂-equivalent greenhouse gases (GHGs), i.e., about 4.5–5% of the global fishing fleet emissions. We developed a model of annual fuel consumption for the large-scale purse seiners operating in the western Indian Ocean as a function of fishing effort, strategy, and vessel characteristics based on an original and unique data set of more than 4300 bunkering operations that spanned the period 2013–2019. We used the model to estimate the total fuel consumption and associated GHG and SO₂ emissions of the Indian Ocean purse seine fishery between 1981 and 2019. Our results showed that the energetic performance of this fishery was characterized by strong interannual variability over the last four decades. This resulted from a combination of variations in tuna abundance but also changes in catchability and fishing strategy. In recent years, the increased targeting of schools associated with fish aggregating devices in response to market incentives combined with the IOTC management measure implemented to rebuild the stock of yellowfin tuna has strongly modified the productivity and spatio-temporal patterns of purse seine fishing. This had effects on fuel consumption and air pollutant emissions. Over the period 2015 to 2019, the purse seine fishery, including its support vessel component, annually consumed about 160,000 t of fuel and emitted 590,000 t of CO2-eq GHG. Furthermore, our results showed that air pollutant emissions can be significantly reduced when limits in fuel composition are imposed. In 2015, SO₂ air pollution exceeded 1500 t, but successive implementation of sulphur limits in the Indian Ocean purse seine fishery in 2016 and 2018 have almost eliminated this pollution. Our findings highlight the need for a routine monitoring of fuel consumption with standardized methods to better assess the determinants of fuel consumption in fisheries and the air pollutants they emit in the atmosphere.
Show more [+] Less [-]Fuel consumption and air emissions in one of the world’s largest commercial fisheries Full text
2021
Chassot, Emmanuel | Antoine, Sharif | Guillotreau, Patrice | Lucas, Juliette | Assan, Cindy | Marguerite, Michel | Bodin, Nathalie
The little information available on fuel consumption and emissions by high seas tuna fisheries indicates that the global tuna fleet may have consumed about 2.5 Mt of fuel in 2009, resulting in the production of about 9 Mt of CO2-equivalent greenhouse gases (GHGs), i.e., about 4.5–5% of the global fishing fleet emissions. We developed a model of annual fuel consumption for the large-scale purse seiners operating in the western Indian Ocean as a function of fishing effort, strategy, and vessel characteristics based on an original and unique data set of more than 4300 bunkering operations that spanned the period 2013–2019. We used the model to estimate the total fuel consumption and associated GHG and SO2 emissions of the Indian Ocean purse seine fishery between 1981 and 2019. Our results showed that the energetic performance of this fishery was characterized by strong interannual variability over the last four decades. This resulted from a combination of variations in tuna abundance but also changes in catchability and fishing strategy. In recent years, the increased targeting of schools associated with fish aggregating devices in response to market incentives combined with the IOTC management measure implemented to rebuild the stock of yellowfin tuna has strongly modified the productivity and spatio-temporal patterns of purse seine fishing. This had effects on fuel consumption and air pollutant emissions. Over the period 2015 to 2019, the purse seine fishery, including its support vessel component, annually consumed about 160,000 t of fuel and emitted 590,000 t of CO2-eq GHG. Furthermore, our results showed that air pollutant emissions can be significantly reduced when limits in fuel composition are imposed. In 2015, SO2 air pollution exceeded 1500 t, but successive implementation of sulphur limits in the Indian Ocean purse seine fishery in 2016 and 2018 have almost eliminated this pollution. Our findings highlight the need for a routine monitoring of fuel consumption with standardized methods to better assess the determinants of fuel consumption in fisheries and the air pollutants they emit in the atmosphere.
Show more [+] Less [-]Perfluorooctane sulfonate alternatives and metabolic syndrome in adults: New evidence from the Isomers of C8 Health Project in China Full text
2021
Yu, Shu | Feng, Wen-Ru | Liang, Zi-Mian | Zeng, Xiao-Yun | Bloom, Michael S. | Hu, Guo-Cheng | Zhou, Yang | Ou, Yan-Qiu | Chu, Chu | Li, Qing-Qing | Yu, Yunjiang | Zeng, Xiao-Wen | Dong, Guang-Hui
Chlorinated polyfluoroalkyl ether sulfonates (Cl-PFESAs), are ubiquitous alternatives to perfluorooctane sulfonate (PFOS), a widely used poly- and perfluoroalkyl substance (PFAS). Despite in vivo and in vitro evidence of metabolic toxicity, no study has explored associations of Cl-PFESAs concentrations with metabolic syndrome (MetS) in a human population. To help address this data gap, we quantified 32 PFAS, including 2 PFOS alternative Cl-PFESAs (6:2 and 8:2 Cl-PFESAs) in serum from 1228 adults participating in the cross-sectional Isomers of C8 Health Project in China study. The odds ratios (ORs) and 95% confidence intervals (CIs) of MetS and its various components were estimated using individual PFAS as a continuous or categorical predictor in multivariate regression models. The association between the overall mixture of PFAS and MetS was examined using probit Bayesian Kernel Machine Regression (BKMR-P). Greater serum PFAS concentrations were associated with higher odds of MetS and demonstrated a statistically significant dose-response trend (P for trend < 0.001). For example, each ln-unit (ng/mL) increase in serum 6:2 Cl-PFESA was associated with a higher prevalence of MetS (OR = 1.52, 95% CI: 1.25, 1.85). MetS was also 2.26 (95% CI: 1.59, 3.23) times more common in the highest quartile of serum 6:2 Cl-PFESA concentration than the lowest, and particularly high among women (OR = 6.41, 95% CI: 3.65, 11.24). The BKMR-P analysis showed a positive association between the overall mixture of measured PFAS and the odds of MetS, but was only limited to women. While our results suggest that exposure to Cl-PFESAs was associated with MetS, additional longitudinal studies are needed to more definitively address the potential health concerns of these PFOS alternatives.
Show more [+] Less [-]Nicosulfuron inhibits atrazine biodegradation by Arthrobacter sp. DNS10:Influencing mechanisms insight from bacteria viability, gene transcription and reactive oxygen species production Full text
2021
Zhao, Jiang | Deng, Shijie | Wang, Lu | Hu, Yang | Cao, Bo | Lv, Jun | Qu, Jianhua | Wang, Lei | Wang, Yifan | Zhang, Ying
Nicosulfuron is a sulfonylurea family herbicide which is commonly applied together with the triazine herbicide atrazine in agricultural practice. However, whether nicosulfuron can influence the biodegradation of atrazine is unclear. Therefore, the influence of nicosulfuron on atrazine removal as well as on cell viability and transcription of atrazine chlorohydrolase gene (trzN) in Arthrobacter sp. DNS10 was investigated in this study. Our results demonstrated that 76.0% of atrazine was degraded in the absence of nicosulfuron after 48h of culture, whereas 63.9, 49.1 and 42.6% was degraded in the presence of 1, 5, and 10 mg/L of nicosulfuron, respectively. Nicosulfuron also induced an increase in the level of intracellular reactive oxygen species (ROS), thereby damaging the cell membrane integrity and inhibiting the growth of the strain DNS10. Flow cytometry analysis revealed that the cell viability of strain DNS10 decreased with an increase in nicosulfuron concentration. The transcription of trzN in strain DNS10 exposed to the three described levels of nicosulfuron was 0.99, 0.72 and 0.52 times, respectively, that without nicosulfuron. In brief, nicosulfuron could inhibit atrazine removal efficiency by strain DNS10 by inducing the over-production of ROS which ultimately enhances the population of membrane-damaged cells, as well as reducing cell viability and trzN transcription. The outcomes of the present study provide new insights into the mechanism of nicosulfuron inhibition on atrazine biodegradation by strain DNS10.
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