خيارات البحث
النتائج 1 - 10 من 51,311
Pollution
1990
Harrison, R. M. (Roy M)
Much has happened in the pollution field since 1982 when the first edition of this work was written. This edition includes new subject areas such as radioactive pollution and chemistry and pollution of the stratosphere.
اظهر المزيد [+] اقل [-]Pollution prevention
1992
Theodore, Louis | McGuinn, Young C.
Food pollution
1972
Marine, Gene | Van Allen, Judith
Multidrug-resistant enteroaggregative Escherichia coli (EAEC) enters dormant state during heat treatment: A potential hazard in municipal sludge
2022
Zhang, Bingni | Fu, Yulong | Wang, Feiyu | Yang, Jiawen | Pan, Zhiyu | Huang, Meiling | Shen, Kewei | Shen, Chaofeng
Reuse of sewage sludge is a general trend and land application is an essential way to reuse sludge. The outbreak of coronavirus disease has raised concerns about human pathogens and their serious threat to public health. The risk of pathogenic bacterial contamination from land application of municipal sludge has not been well assessed. The purpose of this study was to investigate the presence of pathogenic bacteria in municipal sewage sludge and to examine the survival potential of certain multidrug-resistant enteroaggregative Escherichia coli (EAEC) strain isolated from sewage sludge during heat treatment. The sewage sludge produced in the two wastewater treatment plants contained pathogenic bacteria such as pathogenic E. coli, Shigella flexneri, and Citrobacter freundii. The environmental strain of EAEC isolated from the sludge was resistant to eight types of antibiotics. It could also enter the dormant state after 4.5 h of treatment at 55 °C and regrow at 37 °C, while maintaining its antibiotic resistance. Our results indicate that the dormancy of EAEC might be why it is heat-resistant and could not be killed completely during the sludge heat treatment process. Owing to the regrowth of the dormant pathogenic bacteria, it is risky to apply the sludge to land even if the sludge is heat-treated, and there is also a risk of spreading antibiotic resistance.
اظهر المزيد [+] اقل [-]Toxicokinetics of metals in the soil invertebrate Enchytraeus crypticus exposed to field-contaminated soils from a mining area
2022
Zhang, Lulu | Van Gestel, Cornelis A.M. | Li, Zhian
Toxicokinetics may help assessing the risk of metal-contaminated soils by quantifying the development of internal metal concentrations in organisms over time. This study assessed the toxicokinetics in Enchytraeus crypticus of non-essential (Pb and Cd) and essential elements (Zn and Cu) in metal-contaminated field soils from a mining area, containing 3.49–24.3 mg Cd/kg dry soil, 433–1416 mg Pb/kg dry soil, 15.7–44.9 mg Cu/kg dry soil and 1718–6050 mg Zn/kg dry soil. Three different uptake-elimination patterns in E. crypticus were found. Both essential elements (Zn and Cu) showed fast increasing internal concentrations reaching equilibrium within 2 d in the uptake phase, without hardly any elimination after transfer to clean soil. The non-essential Cd showed a slow linear accumulation and excretion with body concentrations not reaching steady state within 21 d. Internal Pb concentrations, however, reached equilibrium within 7 d in the uptake phase. Longer exposure times in ecotoxicological tests, therefore, are required for elements like Cd. Porewater pH and dissolved organic carbon (DOC) levels were the dominant factors controlling Cd uptake from the test soils. The 21-d body Cd and Pb concentrations were best explained from 0.01 M CaCl₂-extractable soil concentrations. Steady-state Cu and Zn body concentrations were independent of soil exposure concentrations. Bioaccumulation factors (BAF) were low for Pb (<0.1 kgₛₒᵢₗ/kgwₒᵣₘ), but high for Cd at 1.78–24.3 kgₛₒᵢₗ/kgwₒᵣₘ, suggesting a potential risk of Cd biomagnification in the terrestrial food chain of the mining area ecosystem.
اظهر المزيد [+] اقل [-]Associations of plasma metal levels with type 2 diabetes and the mediating effects of microRNAs
2022
Nie, Hongli | Hu, Hua | Li, Zhaoyang | Wang, Ruixin | He, Jia | Li, Peiwen | Li, Weiya | Cheng, Xu | An, Jun | Zhang, Zefang | Bi, Jiao | Yao, Jinqiu | Kwok, Woon | Zhang, Xiaomin | He, Meian
The present study aims to determine the associations of multiple plasma metal levels and plasma microRNAs (miRNAs) with diabetes risk, and further explore the mediating effects of plasma miRNAs on the associations of plasma metal with diabetes risk. We detected plasma levels of 23 metals by inductively coupled plasma mass spectrometry (ICP-MS) among 94 newly diagnosed and untreated diabetic cases and 94 healthy controls. The plasma miRNAs were examined by microRNA Array screening and Taqman real-time PCR validation among the same study population. The multivariate logistic regression models were employed to explore the associations of plasma metal and miRNAs levels with diabetes risk. Generalized linear regression models were utilized to investigate the relationships between plasma metal and plasma miRNAs, and mediation analysis was used to assess the mediating effects of plasma miRNAs on the relationships between plasma metals and diabetes risk. Plasma aluminum (Al), titanium (Ti), copper (Cu), zinc (Zn), selenium (Se), rubidium (Rb), strontium (Sr), barium (Ba), and Thallium (Tl) levels were correlated with elevated diabetic risk while molybdenum (Mo) with decreased diabetic risk (P < 0.05 after FDR multiple correction). MiR-122–5p and miR-3141 were positively associated with diabetes risk (all P < 0.05). Ti, Cu, and Zn were positively correlated with miR-122–5p (P = 0.001, 0.028 and 0.004 respectively). Ti, Cu, and Se were positively correlated with miR-3141 (P = 0.003, 0.015, and 0.031 respectively). In addition, Zn was positively correlated with miR-193b-3p (P = 0.002). Ti was negatively correlated with miR-26b-3p (P = 0.016), while Mo and miR-26b-3p were positively correlated (P = 0.042). In the mediation analysis, miR-122–5p mediated 48.0% of the association between Ti and diabetes risk. The biological mechanisms of the association are needed to be explored in further studies.
اظهر المزيد [+] اقل [-]Changing bioavailability of per- and polyfluoroalkyl substances (PFAS) to plant in biosolids amended soil through stabilization or mobilization
2022
Zhang, Weilan | Liang, Yanna
Biosolids containing per- and polyfluoroalkyl substances (PFAS) could contaminate the receiving environments once they are land applied. In this study, we evaluated the feasibility of controlling the bioavailability of PFAS in biosolids to timothy-grass through stabilization or mobilization approaches. Stabilization was accomplished by adding a sorbent (i.e. granular activated carbon (GAC), RemBind, biochar) to biosolids, while mobilization was achieved by adding a surfactant, sodium dodecyl sulphate (SDS), to biosolids. The results showed that the ΣPFAS concentration in grass shoots grown in biosolids amended soil treated by GAC or RemBind at 2% was only 2.77% and 3.35% of the ΣPFAS concentration detected in shoots grown in biosolids amended soil without a sorbent, respectively, indicating the effectiveness of GAC and RemBind for stabilizing PFAS and reduce their bioavailability. On the other hand, mobilization by adding SDS to biosolids at a dose range of 10–100 mg/kg significantly increased the plant uptake of ΣPFAS by 15.48%–108.57%. Thus, mobilization by adding SDS could be a valuable approach for enhancing the PFAS removal if phytoremediation is applied. Moreover, higher rate of PFAS uptake took place after grass cutting was observed in this study. Thus, proper mowing and regrowth of timothy-grass could lead to efficient and cost-effective removal of PFAS from biosolids amended soil through phytoremediation and leave the site clean to be used for other purposes.
اظهر المزيد [+] اقل [-]Characterization of anthropogenic marine macro-debris affecting coral habitat in the highly urbanized seascape of Mumbai megacity
2022
De, Kalyan | Sautya, Sabyasachi | Gaikwad, Santosh | Mitra, Aditi | Nanajkar, Mandar
Marine debris has become a major form of pollution and a serious ecosystem health concern. The present study evaluates the accumulation, origin, and fate of debris in intertidal coral habitats of Mumbai-one of the world's highly populated coastal cities on the west coast of India. Predominantly, seven hermatypic coral species belonging to seven genera and five families were identified and mainly represented by Pseudosidastrea, Porites, and Bernardpora. In terms of number, the mean density of marine debris was 1.60 ± 0.13 SE items/m², which is higher than the global average. The mean density of plastic debris was 1.46 ± 0.14 SE items/m². Approximately 9% of total coral colonies were in physical contact with debris, and 22% of these colonies showed visible signs of partial bleaching. Single use plastic bags and wrappers were dominant plastic debris. The study area was characterized as ‘very poor cleanliness’ according to the Beach Quality Indexes, which include the Clean Coast Index, General Index, and Hazardous Items Index. The numerical model indicates the influence of river discharge and probable areas of plastic accumulation with high tidal currents in this region, maneuvering the spatial advection of litter in the nearshore areas. Combined analysis of ground-truthing and model simulation implies that the possible contributing sources of litter were representatives of land-based and sea-originated. The overall results point to increasing anthropogenic stressors threatening coastal coral communities, including marine debris pollution. It is advocated to adopt an integrated coastal zone management approach supported by coordinated policy frameworks could guide the mitigation of the debris footprint in coastal environments.
اظهر المزيد [+] اقل [-]Characteristics, correlations and health risks of PCDD/Fs and heavy metals in surface soil near municipal solid waste incineration plants in Southwest China
2022
Bo, Xin | Guo, Jing | Wan, Ruxing | Jia, Yuling | Yang, Zhaoxu | Lu, Yong | Wei, Min
As primary anthropogenic emission source of toxic pollutants such as heavy metals and polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs), municipal solid waste (MSW) incineration has caused worldwide concern. However, a comprehensive analysis of the pollution characteristics and health risks of PCDD/Fs and heavy metals in soils around MSW incineration plants is lacking. In this study, 17 PCDD/Fs and 11 heavy metals in soil samples collected near MSW incineration plants in Sichuan province were investigated to evaluate their pollution characteristics and potential health risk. Sichuan was selected as the study area because the MSW incineration amount in this province ranks first among all inland provinces in China. The PCDD/Fs concentrations ranged from 0.30 to 7.50 ng I-TEQ/kg, which were significantly below risk screening and intervention thresholds. Regarding heavy metals, principal component analysis suggested that Hg, Pb and Zn were the primary metals emitted from the MSW incineration plants. Cluster analysis of PCDD/Fs and heavy metals showed that of PCDD/Fs homologs and heavy metals (e.g., Hg, Pb, Zn and Cd) were clustered into one group, indicating the coexistence and coaccumulation of heavy metals (especially Hg, Pb, Zn, and Cd) and PCDD/Fs in soil. These heavy metals are thus candidate tracers for PCDD/Fs in soil near MSW incineration plants. A health risk analysis found that the carcinogenic and non-carcinogenic risks of PCDD/Fs and heavy metals (except for Ni) in the soil samples were all within acceptable levels. This study provides new insights into correlations and health risks of PCDD/Fs and heavy metals in surface soil near MSW incineration plants. The findings have implications for future studies of environmental and human health risk analysis related to waste incineration.
اظهر المزيد [+] اقل [-]Effects of soil fluoride pollution on wheat growth and biomass production, leaf injury index, powdery mildew infestation and trace metal uptake
2022
Ahmad, Muhammad Nauman | Zia, Afia | van den Berg, Leon | Ahmad, Yaseen | Mahmood, Rashid | Dawar, Khadim Muhammad | Alam, Syed Sartaj | Riaz, Muhammad | Ashmore, Mike
Fluoride (F) is an emerging pollutant that originates from multiple sources and adversely affects plant growth and nutrient bioavailability in soil. This greenhouse study investigated the effects of soil F (0, 10, 20, 50, 100, 200 mg kg⁻¹) on morpho-physiological growth characteristics of wheat, soil F contents, and bioavailability and uptake of F, phosphorus (P), sulphur (S), potassium (K), calcium (Ca), magnesium (Mg), aluminium (Al), iron (Fe), manganese (Mn), silicon (Si) and zinc (Zn) by wheat. Higher F significantly reduced plant height and number of leaves particularly at early growth stages and increased visible leaf injury index. Powdery mildew infestation coincided with leafy injury and was higher in elevated soil F treatments. Fluoride treatments (>50 mg kg⁻¹) significantly increased water (H₂O)- and calcium chloride (CaCl₂)-extractable F contents in soil. Water-extractable soil F contents from soil in all concentration were higher than CaCl₂-extractable F. This increased F bioavailability resulted in significantly higher F uptake and accumulation in live leaves, dead leaves and grains of wheat which followed order: live leaves > dead leaves > grains. Leaf injury index and number of dead leaves correlated significantly positively with soil H₂O- and CaCl₂-extractable F contents. Patterns of nutrient (P, K, S) and trace metals (Al, Ca, Mg, Fe, Mn, Si, Zn) varied significantly with F concentrations and between live and dead leaves, and grains except for Zn. Dead leaves generally had higher nutrients and trace metals than live leaves and grains. Fluoride contents in live leaves, dead leaves and grains showed positive correlations with nutrient elements but negative with trace metals. Number of dead leaves correlated negatively with Al, Ca, Fe, Mg, S and Si but positively with P and Zn contents in dead leaves whereas leaf injury index showed positive correlation with Fe, K, P, Si, Zn, S but negative with Al, Ca and Mg contents. These observations provided evidence of higher F uptake and associated impairment in nutrient and trace metal accumulation which caused leaf injury accompanied by powdery mildew infestation in wheat. However, further research in the region is required to confirm the relationship between F pollution, leaf injury and trace metal accumulation in crops under field conditions.
اظهر المزيد [+] اقل [-]