خيارات البحث
النتائج 1051 - 1060 من 6,473
Soil contamination by potentially toxic elements and the associated human health risk in geo- and anthropogenic contaminated soils: A case study from the temperate region (Germany) and the arid region (Egypt)
2020
Shaheen, Sabry M. | Antoniadis, Vasileios | Kwon, Eilhann | Song, Hocheol | Wang, Shan-Li | Hseu, Zeng-Yei | Rinklebe, Jörg
The aim of this study was to assess the soil contamination caused by potentially toxic elements (Al, As, Co, Cr, Cu, Fe, Mn, Mo, Ni, Se, V, and Zn) using various indices and the associated risk of human health for adults and children in selected soils from Germany (Calcic Luvisols, Tidalic Fluvisols, Haplic Gleysols, and Eutric Fluvisols) and Egypt (Haplic Calcisols, Sodic Fluvisols, and Eutric Fluvisols). Soil contamination degree has been assessed using indices such as contamination factor (CF), pollution load index (PLI), geo-accumulation index (Igₑₒ), and enrichment factor. We also assessed the health risk for children and for male and female adults. Chromium, Cu, As, Mo, Ni, Se, and Zn in the German Fluvisols had high CF of >6, while in the Egyptian Fluvisols Se, Mo, As, and Al revealed a high CF. The PLI (1.1–5.2) was higher than unity in most soils (except for Tidalic Fluvisols), while the most important contributor was Se, followed by Mo and As in the Egyptian Fluvisols, and by Cr, Cu, and Zn in the German Fluvisols. The median value of hazard index (HI) for children in the studied soils indicated an elevated health risk (higher than one), especially in the German Fluvisols (HI = 4.0–29.0) and in the Egyptian Fluvisols (HI = 2.2–5.2). For adults, median HIs in all soils were lower than unity for both males and females. The key contributor to HI was As in the whole soil profiles, accounting for about 59% of the total HIs in all three person groupings. Our findings show that in the studied multi-element contaminated soils the risk for children’s health is higher than for adults; while mainly As (and Al, Cr, Cu, and Fe) contributed significantly to soil-derived health risk.
اظهر المزيد [+] اقل [-]Maximizing HBr/Br2 in the flue gas and prevention of secondary pollution during the oxy-combustion of brominated waste electrical and electronic equipment part 1- thermodynamic considerations
2020
Farshchi Tabrizi, Farshad | Dunker, Martin | Hiller, Andreas | Beckmann, Michael
Organobromine compounds comprise between 3 and 8% by weight of WEEE and mainly converted to HBr and Br₂ in the incinerator. However, these compounds, during the cooling of the flue gases, can form the PBDD/Fs in the post-combustion area of the furnace. Due to the many benefits of Oxy-combustion process, our group has developed a fluidised bed incinerator for burning the WEEE and plan to maximise HBr/Br₂ in the flue gas. Experimental results presented in the recent papers show that the combustion of the WEEE particles attains quickly to thermodynamic equilibrium. Thermodynamic modelling can, therefore, predict the concentration of brominated pollutants, particularly HBr, Br₂, HgBr₂, and Br˙ in the flue gas. In this paper, the effect of various parameters for increasing the HBr/Br₂ ratio in the flue gas has been investigated. The model shows that the addition of very small amounts of hydrogen in the post-combustion area can convert Br₂ and Br˙ into HBr.
اظهر المزيد [+] اقل [-]Bisphenol analogue concentrations in human breast milk and their associations with postnatal infant growth
2020
Jin, Hangbiao | Xie, Jiahui | Mao, Lingling | Zhao, Meirong | Bai, Xiaoxia | Wen, Jie | Shen, Tao | Wu, Pengfei
Many studies show that bisphenol A (BPA) is widespread in human breast milk. However, the occurrence of other bisphenol analogues (BPs), including bisphenol S (BPS), bisphenol F (BPF), and bisphenol AF (BPAF), in breast milk is still not well known. In this study, breast milk samples were collected from 190 women in Hangzhou, China, with the aims to characterize the occurrence of BPA, BPS, BPF, and BPAF in these samples and to investigate their effects on postnatal growth of infants through breast milk consumption. BPA (mean 2.5 ng/mL, range < LOD–15 ng/mL) was the most abundant BP in breast milk, followed by BPS (0.19 ng/mL, <LOD–1.3 ng/mL) and BPAF (0.092 ng/mL, <LOD–0.58 ng/mL). BPF was not detected in all breast milk samples. We firstly found that breast milk concentrations of BPA were negatively correlated with infant’s weight or length gain rate. Daily intakes (DIs) of BPs via the consumption of breast milk were calculated for infants, and the mean DI values were 531 ng/kg/day, 53 ng/kg/day, and 24 ng/kg/day for BPA, BPS, and BPAF, respectively. Overall, this study firstly demonstrats that the lactation exposure to BPA through breast milk consumption may affect the postnatal growth of infants.
اظهر المزيد [+] اقل [-]In ovo very early-in-life exposure to diesel exhaust induced cardiopulmonary toxicity in a hatchling chick model
2020
Jiang, Qixiao | Xu, Xiaohui | Zhang, Chao | Luo, Jing | Lv, Na | Shi, Limei | Ji, Andong | Gao, Mengyu | Chen, Feilong | Cui, Lianhua | Zheng, Yuxin
Diesel exhaust (DE) had been associated with cardiopulmonary toxicity and developmental toxicity. However, neonatal very early-in-life exposure had not been extensively studied previously. To investigate the potential effects of neonatal very early-in-life exposure to DE, a brand-new chicken embryo in ovo exposure model had been established, with which the cardiopulmonary effects of DE exposure via air cell infusion at embryonic day 18/19 (ED18/19) were assessed in hatchling chicks post-hatch 0-, 1-, or 2-weeks. Heart rates were assessed with electrocardiography. Cardiac and pulmonary morphologies were investigated with histopathological methods. Cardiopulmonary effects were explored with immunohistochemistry for alpha smooth muscle actin (alpha-SMA). In further investigations, the expression levels of phosphorylated AhR, serum levels of TGF-β1, phosphorylated SMAD2/3 and phosphorylated p38MAPK were assessed in the lung tissues. Significantly elevated heart rates, increased right ventricular wall thickness and cardiac collagen deposition were observed in the hearts of exposed hatchling chicks. Significantly increased collagen deposition as well as increased vascular alpha-SMA layer thickness/decreased cavity area were observed in exposed animal lungs. These effects persisted up to two weeks post-hatch. Mechanistic studies revealed elevated phosphorylated AhR expression levels in 0-week and 1-week chicken lungs, while phosphorylated SMAD2/3 levels significantly increased in 0-week chicken lungs but decreased in 2-week chicken lungs following DE exposure. Phosphorylation of p38MAPK did not remarkably increase until 2-week post-hatch. In summary, the novel chicken neonatal very early-in-life exposure model effectively exposed the chicken embryos during the neonatal initial breathing, resulting in cardiopulmonary toxicity, which is associated with AHR, TGF-β1 and MAPK signaling.
اظهر المزيد [+] اقل [-]iTRAQ-based proteomic analysis on the mitochondrial responses in gill tissues of juvenile olive flounder Paralichthys olivaceus exposed to cadmium
2020
Lu, Zhen | Wang, Shuang | Ji, Chenglong | Li, Fei | Cong, Ming | Shan, Xiujuan | Wu, Huifeng
Cadmium (Cd) is an important heavy metal pollutant in the Bohai Sea. Mitochondria are recognized as the key target for Cd toxicity. However, mitochondrial responses to Cd have not been fully investigated in marine fishes. In this study, the mitochondrial responses were characterized in gills of juvenile flounder Paralichthys olivaceus treated with two environmentally relevant concentrations (5 and 50 μg/L) of Cd for 14 days by determination of mitochondrial membrane potential (MMP), observation of mitochondrial morphology and quantitative proteomic analysis. Both Cd treatments significantly decreased MMPs of mitochondria from flounder gills. Mitochondrial morphologies were altered in Cd-treated flounder samples, indicated by more and smaller mitochondria. iTRAQ-based proteomic analysis indicated that a total of 128 proteins were differentially expressed in both Cd treatments. These proteins were basically involved in various biological processes in gill mitochondria, including mitochondrial morphology and import, tricarboxylic acid (TCA) cycle, oxidative phosphorylation (OXPHOS), primary bile acid biosynthesis, stress resistance and apoptosis. These results indicated that dynamic regulations of energy homeostasis, cholesterol metabolism, stress resistance, apoptosis, and mitochondrial morphology in gill mitochondria might play significant roles in response to Cd toxicity. Overall, this study provided a global view on mitochondrial toxicity of Cd in flounder gills using iTRAQ-based proteomics.
اظهر المزيد [+] اقل [-]Environmental dissemination of carbapenemase-producing Enterobacteriaceae in rivers in Switzerland
2020
Bleichenbacher, Stephanie | Stevens, Marc J.A. | Zurfluh, Katrin | Perreten, Vincent | Endimiani, Andrea | Stephan, Roger | Nüesch-Inderbinen, Magdalena
The aquatic environment takes on a key role in the dissemination of antimicrobial-resistant Enterobacteriaceae. This study assesses the occurrence of carbapenemase-producing Enterobacteriaceae (CPE) in freshwater samples from rivers, inland canals, and streams throughout Switzerland, and characterizes the isolated strains using phenotypic and NGS-based genotypic methods. CPE producing KPC-2 (n = 2), KPC-3 (n = 1), NDM-5 (n = 3), OXA-48 (n = 3), OXA-181 (n = 6), and VIM-1 (n = 2) were detected in 17/164 of the water samples. Seven Escherichia coli had sequence types (STs) that belonged to extra-intestinal pathogenic clonal lineages ST38, ST73, ST167, ST410, and ST648. The majority (16/17) of the carbapenemase genes were located on plasmids, including the widespread IncC (n = 1), IncFIIA (n = 1), and IncFIIB plasmids (n = 4), the epidemic IncL (n = 1) and IncX3 (n = 5) plasmids, a rare Col156 plasmid (n = 1), and the mosaic IncFIB, IncR, and IncQ plasmids (n = 3). Plasmids were composed of elements that were identical to those of resistance plasmids retrieved from clinical and veterinary isolates locally and worldwide. Our data show environmental dissemination of high-risk CPE clones in Switzerland. Epidemic and mosaic-like plasmids carrying clinically relevant carbapenemase genes are replicating and evolving pollutants of river ecosystems, representing a threat to public health and environmental integrity.
اظهر المزيد [+] اقل [-]In vivo distribution and biotransformation of Tris (1,3-dichloro-2-propyl) phosphate in mice
2020
Zhu, Ting | Zheng, Xiao-Bo | Yan, Xiao | Tang, Bin | Zheng, Jing | Luo, Xiao-Jun | Zhu, Chun-You | Yu, Yun-Jiang | Mai, Bi-Xian
Phosphorus flame retardants (PFRs) have been widely detected in environmental media and human samples. Understanding the distribution and biotransformation of PFRs is important for toxicological research of PFRs in humans. C57BL/6 mice were administered with 300 mg/kg body weight/day of tris (1,3-dichloro-2-propyl) phosphate (TDCIPP) for 35 consecutive days. The liver, kidney, muscle, feces, urine and hair samples were collected to investigate the distribution of TDCIPP and its diester, bis (1,3-dichloro-2-propyl) phosphate (BDCIPP), as well as other potential metabolites of TDCIPP. Concentrations of TDCIPP in muscle (535.7 ± 192.2 ng/g wet weight) were significantly higher than those in liver (186.9 ± 55.0 ng/g wet weight) and kidney (43.5 ± 12.0 ng/g wet weight) (p < 0.05), while concentrations of BDCIPP were higher in kidney (2189.2 ± 420.7 ng/g wet weight) and liver (1337.1 ± 249.6 ng/g wet weight) than other tissues. The distribution of TDCIPP and BDCIPP in mice is tissue-specific, TDCIPP tends to accumulate in muscle, while BDCIPP tends to enrich in kidney and liver. BDCIPP was prone to be eliminated by urine, which may result in the high levels of BDCIPP in urine. Urine and feces had significantly higher concentrations of BDCIPP than TDCIPP (p < 0.05), which demonstrated that BDCIPP is an important metabolite of TDCIPP. Hair could serve as a suitable and reliable biomarker for TDCIPP and also metabolites of TDCIPP. Multifarious metabolites of TDCIPP were identified in various matrices of mice, especially urine. Seven novel metabolites of TDCIPP were identified for the first time. TDCIPP metabolic pathways involved oxidative dealkylation, oxidative dehalogenation, reoxidation, dehalogenation with dehydrogenation. The metabolites identified in the present study could serve as candidate biomarkers for future human biomonitoring studies.
اظهر المزيد [+] اقل [-]Dynamic interactions between soil cadmium and zinc affect cadmium phytoavailability to rice and wheat: Regional investigation and risk modeling
2020
Yang, Yang | Li, Yanling | Chen, Weiping | Wang, Meie | Wang, Tianqi | Dai, Yating
Characterizing the interactions between Cd and Zn with respect to the soil soluble Cd and crop Cd uptake allows the development of risk-based approaches to the performance of grain crops. By means of a three-year survey of 358 rice fields and 206 wheat fields across China, this study investigated the effect of Cd–Zn interactions on the phytoavailability of Cd to rice and wheat. The interactive nature between the Cd:Zn ratio and pH of soil affected crop Cd uptake, and the resulting grain Cd intake risk, were examined by the Free-Ion Activity-based model and probability analysis. In highly acidic rice soils (pH < 5.9), soil Zn had no effect on rice Cd uptake, whereas, under near-neutral conditions (pH > 5.9), a site-specific influence of soil Zn on grain Cd concentration was found. Soil Zn could inhibit Cd uptake and translocation by the plant in soil-wheat system when the soil Cd:Zn ratio decreased to 0.0083 and lower. Rice grain poses a significant health risk to local consumers due to its high Cd accumulation and its low Zn accumulation. In order to reduce the health risks from dietary Cd to local consumers, approximately 63.9% of the rice fields and 30.5% of the wheat fields require strategies ameliorating soil acidity in rice soils and increasing Zn concentrations in wheat soils.
اظهر المزيد [+] اقل [-]Size-dependent effects of polystyrene plastic particles on the nematode Caenorhabditis elegans as related to soil physicochemical properties
2020
Kim, Shin Woong | Kim, Dasom | Jeong, Seung-Woo | An, Youn-Joo
Plastic polymers are widely used in various applications and are thus prevalent in the environment. Over time, these polymers are slowly degraded into nano- and micro-scale particles. In this study, the free-living nematode, Caenorhabditis elegans, was exposed to polystyrene particles of two different sizes (42 and 530 nm) in both liquid and soil media. The number of offspring significantly (p < 0.05) decreased at polystyrene concentrations of 100 mg/L and 10 mg/kg in liquid and soil media, respectively. In soil media, but not liquid media, C. elegans was more sensitive to the larger particles (530 nm) than the smaller particles (42 nm), and the median effective concentration (EC₅₀) values of the 42 and 530 nm-sized particles were found to be > 100 and 14.23 (8.91–22.72) mg/kg, respectively. We performed the same toxicity bioassay on five different field-soil samples with different physicochemical properties and found that the size-dependent effects were intensified in clay-rich soil samples. A principal component analysis showed that the bulk density, cation exchange capacity, clay content, and sand content were the dominant factors influencing the toxicity of the 530 nm-sized polystyrene particles. Therefore, we conclude that the soil composition has a significant effect on the toxicity induced by these 530 nm-sized polystyrene particles.
اظهر المزيد [+] اقل [-]Occurrence and risk assessment of psychoactive substances in tap water from China
2020
Wang, Zeyuan | Gao, Siyue | Dai, Qingying | Zhao, Meirong | Yang, Fangxing
Psychoactive substances are becoming a new concern in aquatic environment along with the increase in use of these substances. In this study, 23 psychoactive substances were investigated in the tap water collected in 63 sites in China. Eighteen out of 23 psychoactive substances were detected at the range of < method detection limits (MDLs) to 24.9 ng L-1. It was found that diazepam and temazepam were the major psychoactive substances in the tap water with the median concentration of 1.0 and 0.06 ng L⁻¹, respectively. The high exposure dose for each psychoactive substance was calculated from 0.6 to 855 pg kg⁻¹ bw d⁻¹ and showed an order of men ≥ boys ≥ girls ≥ women. Risk assessment revealed there was little risk of psychoactive substances on human health at current residual levels.
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