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The effect of an antimony resistant bacterium on the iron plaque fraction and antimony uptake by rice seedlings
2020
Long, Jiumei | Zhou, Dongsheng | Li, Bingyu | Zhou, Yimin | Li, Yongjie | Lei, Ming
Iron plaque (IP) is crucial in mitigating antimony (Sb) uptake and accumulation in rice plants, while, few studies focused on the effect of the iron plaque-associated Sb resistant bacteria on IP and Sb uptake into rice plants. Here, the effect of a Sb resistant bacterium (GenBank accession No. MH345840, with potential of conversion soluble Sb(III) into insoluble Sb₂O₃) on IP and Sb(III)/Sb(V) uptake under hydroponic condition was investigated. The results showed that in the presence of Sb(III), a large quantity of bacterial cells consorted with IP on rice roots, the bacterial inoculum altered the IP fraction distribution without enhancing its amount. However, it reduced Sb(III) uptake into rice roots. On contrary, seldom bacterial cells associated with the IP on rice roots in the presence of the Sb(V), the bacterial inoculum increased the IP amount slightly, and did not decline the Sb(V) uptake into rice roots. It also showed that the bacterial inoculum decreased Sb concentrations in rice shoots greatly in both Sb(III) and Sb(V) supplied treatments.
Afficher plus [+] Moins [-]Multi-city study on air pollution and hospital outpatient visits for asthma in China
2020
Lü, Peng | Zhang, Yongming | Lin, Jiangtao | Xia, Guoxin | Zhang, Wenyi | Knibbs, Luke D. | Morgan, Geoffrey G. | Jalaludin, Bin | Marks, Guy | Abramson, Michael | Li, Shanshan | Guo, Yuming
The proportion of asthma patients with mild to moderate exacerbations is far greater than the number who experience episodes that are severe enough to require emergency room visits or hospital admission. However the routinely collected data from hospitals is absent in the past.To evaluate associations between short-term exposures to air pollutants and hospital outpatient visits for asthma in China.We obtained data for 143,057 asthma outpatient visits from the largest hospitals in 17 Chinese cities, between Jan 01 2013 and Dec 31 2015. We used daily concentrations of air pollutants measured by the China National Environmental Monitoring Centre. We used a time-stratified case-crossover design, and fitted conditional logistic regression models to determine the associations.Particulate matter ≤10μm in diameter (PM10) and nitrogen dioxide (NO2) were associated with increased risks of hospital outpatient visits for asthma on the same day, while the effects were delayed for particulate matter ≤2.5μm in diameter (PM2.5) and sulphur dioxide (SO2). For the cumulative effect model at lag05 days, 10 μg/m3 increase in air pollutants concentrations were correlated with hospital outpatient visits for asthma with odds ratios (ORs) and 95% confidence intervals 1.004 (1.000-1.008) for PM2.5, 1.005 (1.002-1.008) for PM10, 1.030 (1.021-1.040) for NO2, and 1.015 (1.008-1.021) for SO2. Almost one in nine (10.9%; 7.7, 13.9%) hospital outpatient visits for asthma were attributable to NO2.Short-term exposures to PM2.5, PM10, NO2 and SO2 were associated with hospital outpatient visits for asthma in China.
Afficher plus [+] Moins [-]The effects of wastewater effluent on multiple behaviours in the amphipod, Gammarus pulex
2020
Love, Adrian C. | Crooks, Neil | Ford, Alex T.
The prevalence of pharmaceuticals and personal care products (PPCPs) in lotic habitats is increasing, with the main source of these contaminants being effluent from waste water treatment works (WwTW). There is still much uncertainty about the impacts of these PPCPs at environmentally relevant concentrations and their potential effects on aquatic ecology. Behaviour is a sensitive endpoint which can help evaluate possible population level effects from changes in physiology. This paper evaluates the effects of WwTW effluent on a range of behaviours in the freshwater invertebrate, Gammarus pulex. Effluent taken from the outflow of two WwTW in southern England was used in the study. Behavioural analyses, namely feeding rate, phototaxis, activity, velocity and precopula pairing, were measured in G. pulex following a period of one and three weeks after exposure to a 50% or 100% effluent and a control. Mortality remained very low throughout the 3 week experiment (0–10%, n = 20) and no significant changes in moulting frequency were observed (p > 0.05). No significant effects on feeding or velocity or phototaxis following 3 weeks of effluent exposures were observed (p > 0.05). However, significant reductions were observed in the overall activity over 3 weeks across which appeared to be exacerbated by exposure to effluents. Interestingly, males exposed for 3 weeks to WwTW effluent re-paired with unexposed females significantly faster (4-6x) than control animals. This result was consistent between the effluents taken from the two WwTW. The implications of these behavioural changes are currently unknown but highlight the need for a varied set of tools to study the behavioural changes in wildlife.
Afficher plus [+] Moins [-]Pesticide exposure and related health problems among family members of farmworkers in southeast Iran. A case-control study
2020
Abbasi-Jorjandi, Mojtaba | Asadikaram, Gholamreza | Abolhassani, Moslem | Fallah, Hossein | Abdollahdokht, Danial | Salimi, Fouzieh | Faramarz, Sanaz | Pournamdari, Mostafa
Pesticides used in agriculture are some of the most common pollutants in the world. This study aimed to investigate the effects of Organophosphorus Pesticides (OPPs) and Organochlorine Pesticides (OCPs) on the families of farmworkers in the southeast of Iran.In the present case-control study, 141 family members of farmworkers (as the case group) and 59 family members of non-farmworkers (as the controls) were recruited. Serum levels of OCPs such as α-HCH, β-HCH, γ-HCH, 2,4-DDE, 4,4-DDE, 2,4-DDT, and 4,4-DDT were determined. In addition, erythrocyte acetylcholinesterase (AChE) activity, malondialdehyde (MDA), total antioxidant capacity (TAC), protein carbonyl (PC), nitric oxide (NO) serum levels, arylesterase activity of paraoxonase 1 (PON-1), superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) activity were determined in all participants. Furthermore, distance to farmlands, education, crops, type, and the number of consumed fruits were evaluated for each individual separately.The erythrocyte AChE activity and serum activities of GPx, SOD, and PON-1 and TAC levels were significantly decreased, whereas the concentration of MDA, PC, NO, and seven OCPs were significantly increased in the farmworkers’ families as compared to the controls. Spearman correlation and linear regression suggest that OCPs increase the oxidative stress in farmworkers’ family members. Moreover, distance, education, farming precedence, products, and ventilation had significant effects on the OCP levels and increased the odds ratio of OCP levels in farmworkers’ families.With regards to the data obtained in this study, it was revealed that OCPs as illegal pesticides and OPPs were higher than expected in the farmworkers’ family members. Furthermore, exposure to OCPs and OPPs, apart from the other effects on the body, leads to oxidative stress (OS) that may cause serious diseases in the exposed populations.
Afficher plus [+] Moins [-]Different roles of silica nanoparticles played in virus transport in saturated and unsaturated porous media
2020
Qin, Yunqi | Wen, Zong | Zhang, Wenjing | Chai, Juanfen | Liu, Dan | Wu, Shengyu
Because of the complexity of contaminants infiltrating groundwater, it is necessary to study the co-transport of contaminants in the vadose and saturated zones. To investigate the role of inorganic colloids in the transport of biocolloids through porous media, a series of experiments were performed using columns packed with sand. The Escherichia coli phage (E. coli phage) was used as the model virus and silica as the model colloid in this study. The model virus exhibited a higher degree of attachment when compared with silica under similar experimental conditions. Under unsaturated flow conditions, the degree of virus retention was higher than in the corresponding saturated flow case, regardless of the presence of silica. Mass recovery and breakthrough curve data showed that silica hindered virus transport in saturated porous media. The model virus exhibited a higher degree of retention in the presence of silica. This could be related to pore structure changes caused by aggregated virus-silica particles located within the pores of the sand. Conversely, the suspended virus retained at the air-water interface provided new retention sites for other colloids; the retention was observed to be higher in the presence of colloidal silica in the saturated columns. In the corresponding unsaturated experiments, silica was observed to play the opposite function with respect to virus transport, which demonstrated that silica facilitated virus transport in the presence of unsaturated porous media. Capillary forces were stronger than the virus-silica interactions, and inhibited the aggregation of particles. Suspended silica competes with the virus for sorption sites because of a high affinity for the air-water interface. This competition inhibits virus retention by electrostatic repulsion of like-charged particles, and concomitantly facilitates virus transport under unsaturated conditions.
Afficher plus [+] Moins [-]Exposure to ambient air pollution and blood lipids in children and adolescents: A national population based study in China
2020
Gui, Zhao-Huan | Yang, Bo-Yi | Zou, Zhi-Yong | Ma, Jun | Jing, Jin | Wang, Hai-Jun | Dong, Guang-Hui | Ma, Yinghua | Guo, Yu-Ming | Chen, Ya-Jun
Few studies have explored the links of air pollution and childhood lipid profiles and dyslipidemias. We aimed to explore this topic in Chinese children and adolescents. This study included 12,814 children aged 7–18 years who participated in a national survey in 2013. Satellite-based spatial-temporal model was used to predict 3-y (2011–2013) average particles with diameters ≤ 1.0 μm (PM₁), ≤2.5 μm (PM₂.₅), ≤10 μm (PM₁₀), and nitrogen dioxide (NO₂) concentrations. Generalized linear mixed models were employed to evaluate the relationships of air pollution and total cholesterol (TC), triglycerides (TG), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), and dyslipidemias. Every 10 μg/m³ increase in PM₁, PM₂.₅, PM₁₀, and NO₂ was related to increases of 6.20% [95% confidence interval (CI): 2.44, 10.10], 5.31% (95%CI: 0.41, 10.44), 3.49% (95%CI: 0.97, 6.08), and 5.25% (95%CI: 1.56, 9.07) in TC, respectively. The odds ratio of hypercholesterolemia associated with a 10 μg/m³ increase in PM₁, PM₂.₅, and NO₂ was 2.15 (95%CI: 1.27, 3.65), 1.70 (95%CI: 1.12, 2.60), and 1.43 (95%CI: 1.05, 1.93), respectively. No associations were found for air pollution and other blood lipids. Long-term PM₁, PM₂.₅, PM₁₀, and NO₂ exposures were positively associated with TC levels and risk of hypercholesterolemia in children and adolescents.
Afficher plus [+] Moins [-]Uptake, translocation, and physiological effects of hematite (α-Fe2O3) nanoparticles in barley (Hordeum vulgare L.)
2020
Tombuloglu, Huseyin | Slimani, Yassine | AlShammari, Thamer Marhoon | Bargouti, Muhammed | Ozdemir, Mehmet | Tombuloglu, Guzin | Ak̲h̲tar, Sult̤ān | Sabit, Hussain | Hakeem, Khalid Rehman | Almessiere, Munirah | Ercan, İsmail | Baykal, Abdulhadi
There has been a growing concern with the environmental influences of nanomaterials due to recent developments in nanotechnology. This study investigates the impact and fate of hematite nanoparticles (α-Fe₂O₃ NPs) (∼14 nm in size) on a crop species, barley (Hordeum vulgare L.). For this purpose, hematite NPs (50, 100, 200, and 400 mg/L) were hydroponically applied to barley at germination and seedling stages (three weeks). Inductively coupled plasma mass spectrophotometry (ICP-MS) along with vibrating sample magnetometer (VSM) techniques were used to track the NPs in plant tissues. The effects of NPs on the root cells were observed by scanning electron microscopy (SEM) and confocal microscopy. Results revealed that α-Fe₂O₃ NPs significantly reduced the germination rate (from 80% in control to 30% in 400 mg/L), as well as chlorophyll (36–39%) and carotenoid (37%) contents. Moreover, the treatment led to a significant decline in the quantum yield of photosystem II (Fv/Fm). Leaf VSM analysis indicated a change in magnetic signal for NPs-treated samples compared with untreated ones, which is mostly attributed to the iron (Fe) ions incorporated within the leaf tissue. Besides, Fe content in the roots and leaf had gradually increased by the increasing doses of NPs, which was confirming NPs’ translocation to the aerial parts. Microscopic observations revealed that α-Fe₂O₃ NPs altered root cell morphology and led to the injury of cell membranes. This study, in the light of our findings, shows that α-Fe₂O₃ NPs (∼14 nm in size) are taken up by the roots of the barley plants, and migrate to the plant leaves. Besides, NPs are phytotoxic for barley as they inhibit germination and pigment biosynthesis. This inhibition is probably due to the injury of the cell membranes in the roots. Therefore, the use of hematite NPs in agriculture and thereby their environmental diffusion must be addressed carefully.
Afficher plus [+] Moins [-]Contamination profiles and health risks of PFASs in groundwater of the Maozhou River basin
2020
Li, Bei-Bei | Hu, Li-Xin | Yang, Yuan-Yuan | Wang, Tuan-Tuan | Liu, Chongxuan | Ying, Guang-Guo
Per-and polyfluoroalkyl substances (PFASs) are a group of chemicals with a wide range of industrial and commercial applications, but little is known about the contamination of PFASs in groundwater and their linkage to surface water. Here we investigated the occurrence of PFASs in groundwater and surface water at the Maozhou River basin in order to understand their contamination profiles and potential health risks. The results showed that total PFASs concentrations ranged from 9.9 to 592.2 ng/L, 50.2–339.9 ng/L and 3.7–74.3 ng/g in groundwater, river water and sediment, respectively. The detection frequencies of C4–C8 chains (C₄–C₈) PFASs were higher than C9–C14 chains PFASs in the river and groundwater. Statistical analysis showed an obvious correlation between the major contaminants in the river and those in the groundwater, indicating the potential linkage of PFASs in the groundwater to the surface water. The wastewater indicator found in groundwater suggested domestic wastewater was only one of the source for the PFASs in the river and groundwater of Maozhou River basin. Moreover, human health risk assessment showed low risks from the PFASs to the residents by drinking groundwater.
Afficher plus [+] Moins [-]Hydroponic growth test of maize sprouts to evaluate As, Cd, Cr and Pb translocation from mineral fertilizer and As and Cr speciation
2020
Fioroto, Alexandre M. | Albuquerque, Luiza G.R. | Carvalho, Alexandrina A.C. | Oliveira, Aline P. | Rodrigues, Fábio | Oliveira, Pedro V.
The present study proposes a maize sprouts hydroponic growth model to evaluate the As, Cd, Cr and Pb translocation from multinutrient fertilizer and to do speciation of As and Cr in this fertilizer and As in parts of plant in order to predict their phytoavailability. X-ray absorption near edge structure (XANES) was employed to speciate As and Cr directly on fertilizer solid sample. Arsenate (Asⱽ) and a solid solution of FeCrO₃ were the major species identified in the samples. The sprouts were hydroponically cultivated in water, fertilizer slurry and fertilizer extract media. Concentrations of As, Cd and Pb measured on leaves of maize sprouts ranged from 0.061 to 0.31 mg kg⁻¹, whereas Cr was not translocated to the aerial parts of sprouts. High performance liquid chromatographic with inductively coupled plasma mass spectrometry (HPLC-ICP-MS) analysis was used to determine As speciation in maize sprouts, as well as in the fertilizer extracts and slurries. Arsenate was the only species identified in the initial fertilizer extract and this information is in agreement with the XANES results. However, the reduction of arsenate to arsenite was observed in extracts and slurries collected after sprout growth, probably due to the action of exudates secreted by plant roots. Arsenite was the predominant species identified in sprouts, the high phosphate concentration in the medium may have contributed to reduce arsenate phytoavailability.
Afficher plus [+] Moins [-]Spatiotemporal variations and influencing factors of PM2.5 concentrations in Beijing, China
2020
Zhang, Licheng | An, Ji | Liu, Mengyang | Li, Zhiwei | Liu, Yue | Tao, Lixin | Liu, Xiangtong | Zhang, Feng | Zheng, Deqiang | Gao, Qi | Guo, Xiuhua | Luo, Yanxia
Fine particulate matter (PM₂.₅) pollution has become a worldwide environmental concern because of its adverse impacts on human health. This study aimed to explore the spatiotemporal variations and influencing factors of PM₂.₅ concentrations in Beijing during the 2013–2018 period, and further analyzed the impacts of environmental protection policies implemented in recent years. Notably, this study employed various statistical methods, i.e., ordinary Kriging interpolation, spatial autocorrelation analysis, time-series analysis and the Bonferroni test, to evaluate the regional and seasonal differences of PM₂.₅ concentrations based on long-term monitoring data. The results illustrated that PM₂.₅ concentrations decreased on a yearly basis, demonstrating that air pollution control policies have achieved initial success. Furthermore, PM₂.₅ concentrations were higher in the winter and in the southern regions. Diurnal variation presented a bimodal distribution, which varied slightly with the season. Relative humidity and wind speed were the principal meteorological factors affecting the distribution of PM₂.₅ concentrations, while precipitation had essentially no effect. A high positive correlation between PM₂.₅ and gaseous pollutants (SO₂, NO₂, and CO) indirectly reflected the contribution of automobile exhaust and coal-fired emissions. Generally, PM₂.₅ concentrations demonstrated strong spatiotemporal variations, and meteorological factors and pollutant emissions played an important role in this.
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