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A survey of extended-spectrum β-lactamase-producing Enterobacteriaceae in environmental water in Okinawa Prefecture of Japan and relationship with indicator organisms
2019
Miyagi, Kazufumi | Hirai, Itaru
Surveys of extended-spectrum β-lactamase-producing Enterobacteriaceae (ESBL-pE) in stream water and untreated wastewater were carried out in Okinawa Prefecture, Japan. Thirty-six samples of water were collected from 18 streams in Okinawa Prefecture, as well as ten samples of wastewater flowing into four wastewater treatment plants (WWTPs). We investigated bacterial species, Escherichia coli O antigen, ESBL phenotype, ESBL genotype, and pulsed-field gel electrophoresis (PFGE) type of isolates, and total viable count and fecal coliforms as indicator organisms. The relation between indicator organisms and ESBL-pE was also validated using the same samples. A total of 141 ESBL-pE including 107 E. coli, 15 Klebsiella pneumoniae, 2 Proteus mirabilis, and 17 other species was isolated from stream water and wastewater. Of the 141 ESBL-pE, 14.9% and 54.6% were found to be blaCTX-M-15 and blaCTX-M-14-like types, respectively, which have been found in hospital isolates in Okinawa. Two pairs of possibly related patterns according to PFGE criteria were isolated from stream water and wastewater in two districts. When ESBL-pE was significantly isolated, total viable count and fecal coliform boundaries were ≥ 6.0 × 10³ CFU/ml and ≥ 4.3 × 10² most probable number/100 ml, respectively. These results suggested that ESBL-pE isolated from stream water is human derived, and that total viable count and fecal coliforms will be useful as indicators for confirming the spread of ESBL-pE to the environment by means of simple hygiene surveys.
Afficher plus [+] Moins [-]Assessment of the human health risks of heavy metals in nine typical areas
2019
Wang, Shiyu | Wu, Wenyong | Liu, Fei
Human health risks of five different heavy metals were assessed in nine typical areas in Asia, Europe, and Africa. The geoaccumulation index (Igₑₒ) of arsenic (As) in Hyderabad (HB), cadmium (Cd) in Veles (VL), and lead (Pb) in Murcia (MC) were found to be 5, indicating extreme contamination. This is related to their high concentrations in soil. The concentration of As in wheat in Niger Delta (ND) and European Union (EU) areas were 3.3 and 2.55 mg/kg, which were 22 and 17 times respectively of the World Health Organization (WHO)/Food and Agriculture Organization (FAO) criteria. In general, the concentrations of heavy metals in wheats were higher than those in corns, indicating that heavy metals were easier to accumulate in wheats than in corns. The human risks induced by the carcinogenic metals As and Cd were much higher than those induced by noncarcinogenic metals in different exposure ways. The human health risks of heavy metals in different exposure ways were Rw₋ᵢₙg > Rc₋ᵢₙg > Rₛ₋ᵢₙg > Rₛ₋dₑᵣ > Rₛ₋ᵢₙₕ. The human health risks induced by wheat ingestion for adults and children accounted for 67.75–97.52% and 69.52–98.04%, respectively, of the total human health risks. The total human health risks in the VL and MC areas were 1.58 × 10⁻⁴ a⁻¹ and 1.3 × 10⁻⁴ a⁻¹ for adults and 1.14 × 10⁻⁴ a⁻¹ and 9.47 × 10⁻⁵ a⁻¹ for children, respectively, which were significantly high according to the Environmental Protection Agency and International Commission on Radiological Protection. The ranking of the total human health risks in different areas were RVL > RMC > RND > REU > RHB > RKY > RTB > RMLV > RNHM. The total human health risks of adults were higher than those of children.
Afficher plus [+] Moins [-]Assessment of organochlorine pesticides in the Himalayan riverine ecosystems from Pakistan using passive sampling techniques
2019
Riz̤vānullāh, | Asghar, Rehana | Baqar, Mujtaba | Mahmood, Adeel | Ali, Syeda Nazish | Sohail, Muhammad | Schäfer, Ralf B. | Eqani, Syed Ali Musstjab Akber Shah
Organochlorine pesticides (OCPs) pose a considerable threat to human and environmental health. Despite most OCPs have been banned, they are still reported to be used in developing countries, including Pakistan. We aimed to identify the distribution, origin, mobility, and potential risks from OCPs in three major environmental compartments, i.e., air, water, and soil, across Azad Jammu and Kashmir valley, Pakistan. The sums of OCPs ranged between 66 and 530 pg/g in soil, 5 and 13 pg/L in surface water, and 14 and 191 pg/m3 in air, respectively. The highest sum of OCPs was observed in the downstream zone of a river that was predominantly influenced by peri-urban and urban areas. The OCP isomers ratios (α-HCH/γ-HCH and o,p′-DDT/p,p′-DDT) indicate use of lindane and technical DDTs mixture as a source of HCH and DDT in the riverine environment. Similarly, the ratios of DDE and DDD/the sum of DDTs, α-endosulfan/β-endosulfan, and cis-chlordane/trans-chlordane indicate recent use of DDTs, endosulfan, and chlordane in the region. The air-water exchange fugacity ratios indicate net volatilization (fw/fa > 1) of α-endosulfan and trans-chlordane, and net deposition (fw/fa < 1) of β-endosulfan, α-HCH, γ-HCH p,p′-DDD, p,p′-DDE, and p,p′-DDT. Based on the risk quotient (RQ) method, we consider the acute ecological risks for fish associated with the levels of OCPs as negligible. However, more studies are recommended to evaluate the chronic ecological risks to other riverine-associated aquatic and terrestrial species as well as human health risks to the POPs exposure through food chain transfer in forthcoming years.
Afficher plus [+] Moins [-]Assessment of metal enrichment and bioavailability in mangrove and mudflat sediments of the tropical (Zuari) estuary, west coast of India
2019
Gadkar, Nikita S. | Nayak, Ganapati N. | Nasnodkar, Maheshwar R.
Mangrove and mudflat sediment cores at the confluence point of the Cumbarjua Canal and the Zuari River were collected and analyzed to assess metal enrichment and bioavailability, with the background of significant bioaccumulation reported in earlier studies within the Zuari Estuary, a recipient of open-cast mining waste containing Fe and Mn. Metals were enriched in mangrove and mudflat sediments due to additions from natural and anthropogenic sources. Contamination factor showed moderate degree of contamination of Fe, Mn, Cu, and Co in mangroves while of Fe, Mn, and Co in mudflats. Pollution load index suggested metal pollution in the sediments of the Zuari Estuary. Metal speciation study indicated largely lithogenic source of Fe (in mudflats), Cu, Zn, and Co, whereas abundant bioavailable Fe (in mangroves) and Mn (in both mangroves and mudflats) suggest their possible mobilization, preferential accumulation, and bioavailability. Further, sediment quality values indicated toxicity of bioavailable Mn and Co, and risk assessment code revealed medium risk of Mn to sediment associated organisms.
Afficher plus [+] Moins [-]Fuzzy risk assessment of modified polychlorinated naphthalenes for enhanced degradation
2019
Gu, Wenwen | Li, Qing | Li, Yu
The three-dimensional quantitative structure-activity relationship (3D-QSAR) model is established for polychlorinated naphthalenes (PCNs) using the biological degradability (total score) results to modify CN-56 to design 37 new derivatives with higher degradability (increased by 14.55–38.79%). Furthermore, five new CN-56 derivatives are selected through evaluation of their persistent organic pollutant properties (toxicity, bioconcentration, long-range transport) and practicability (stability, insulativity, flame retardancy) using 3D-QSAR, density functional theory (DFT) and molecular docking methods. Environmental and health-based risk assessments are conducted using the multimedia fugacity model and fuzzy theory for complete screening of the new CN-56 derivatives. Whereas CN-56 is classed as high risk, three new derivatives can be classed as medium risk. The biodegradability mechanism analysis of the PCNs indicates that the electrostatic property is the main factor that affects the degradability, which provides a favorable theoretical reference to obtain environmentally friendly fire retardant and insulating materials.
Afficher plus [+] Moins [-]The nexus between carbon emissions, poverty, economic growth, and logistics operations-empirical evidence from southeast Asian countries
2019
Khan, Syed Abdul Rehman
This research examines the role of poverty and logistical operations under the circumstance of environmental deterioration with panel data of ASEAN states from 2007 to 2017. The system-generalized method of moments (GMM) was adopted due to the presence of endogeneity. The results indicate that poverty and logistical operations have significant and positive relationship with greater environmental degradation. Because poor people are not skilled, they have to consume natural resources in original and unsustainable way for their survival and profits, which results in greater level of deforestation. On another hand, lacking fuel-efficient/green vehicles and green practices in logistical operations of ASEAN countries, logistics activities mainly depend on fossil fuel consumption, which generates greater carbon emission, methane, and greenhouse emissions that can directly damage the environment and become a primary source of climate change. Therefore, reduction in environmental degradation can be achieved through reduction in poverty and encouraging renewable energy and green practices in logistical operations. In addition, this study also provides detailed policy implications to regulatory bodies and corporate sector in order to improve environmental sustainability through adoption of green practices and reduction in poverty.
Afficher plus [+] Moins [-]Dynamics of the remediating effects of plant litter on the biological and chemical properties of petroleum-contaminated soil
2019
Zhang, Xiaoxi | Zhou, Wenxing | Liu, Hui | Bai, Erlei | Zhang, Jizhou | Liu, Zengwen
To investigate the comprehensive remediating effects of plant residues on biological and chemical properties and the long-term dynamics of these effects, litter from Caragana korshinskii (caragana) or Ziziphus jujuba var. spinosa (jujube) was mixed with three types of soil that were contaminated with 12.49, 27.54, and 45.37 g kg⁻¹ of petroleum. The mixtures were incubated at 20–25 °C with consistent soil moisture for 360 days. Subsequently, the litter impacts on the soil microbial population, the activities of 12 types of soil hydrolytic, and redox enzymes related to the cycling of C, N, and P, and the available N, P, and K contents were determined during the incubation. The results indicated that both types of litter significantly accelerated the reproduction of soil microbes and significantly increased the activities of most of the hydrolytic enzymes and the available nutrient contents after the short-term treatments, while the litters usually simultaneously depressed the activities of polyphenol oxidase and peroxidase in the slightly and moderately contaminated soils. However, the comprehensive remediating effects of the litters on the lightly contaminated soil significantly decreased over time while it recovered to some extent at the end of the experiment. The remediating effects on the seriously contaminated soil exhibited the opposite trend, and their remediating effects on the moderately contaminated soil exhibited continuous weakening. Generally, the remediating effects of the caragana litter were more noticeable than those of the jujube litter, except for the effect on the slightly contaminated soil after 180 days of treatment.
Afficher plus [+] Moins [-]Comparative assessment of using Miscanthus × giganteus for remediation of soils contaminated by heavy metals: a case of military and mining sites
2019
Nurzhanova, Asil | Pidlisnyuk, Valentina | Abit, Kamila | Nurzhanov, Chingiz | Kenessov, Bulat | Stefanovska, Tatyana | Erickson, Larry
Contamination of soil by heavy metals is among the important environmental problems due to their toxicity and negative impact to human health and the environment. An effective method for cleaning the soil from heavy metals is phytoremediation using the second-generation bioenergy species Miscanthus × giganteus. The purpose of this research is to study the benefits of M. × giganteus cultivation at the soils taken from the mining and former military sites contaminated by As, Pb, Zn, Co, Ni, Cr, Cu, V, Mn, Sr, and U as well as at the soil artificially contaminated by Zn and Pb, to evaluate the physiological parameters of the plant, to establish peculiarities of the phytoremediation process, and to characterize the behavior of the plant in relation to the nature and concentrations of the metals in the soils. Results showed that M. × giganteus was resistant to heavy metals (tolerance index ≥ 1) and that the greatest portion of metals accumulated in the root system. The morphological parameters of the plant while grown on different soils are influenced by soil type and the content of contaminants. The stress effect while growing M. × giganteus on soil artificially contaminated by Zn and Pb was evaluated by measuring the content of pigments (chlorophylls a, b, and carotenoids) in the plant’s leaves. The decrease in the total content of chlorophylls, Сₐ ₊ b/Сcₐᵣ and transpiration rate of water along with the increase in the water absorbing capacity were observed. The accumulation of heavy metals in different parts of the plant was determined; bioaccumulation coefficient and values of translocation factor were calculated. The obtained results showed that M. × giganteus was an excluder plant for nine highly toxic elements (As, Pb, Zn, Co, Ni, Cr, Cu, V, U) and an accumulator species for the moderately dangerous elements (Mn, Sr). Further research will be focused on the extraction of stable stimulated plant-growth–promoting rhizobacteria from the rhizosphere of M. × giganteus and formulation on that base the plant-bacterial associations as well as on the comparison of the plant physiological parameters, biochemical soil activity, and accumulation of heavy metals in the Miscanthus tissues between first and second vegetations.
Afficher plus [+] Moins [-]Process of fruit peel waste biorefinery: a case study of citrus waste biorefinery, its environmental impacts and recommendations
2019
Joglekar, Saurabh N. | Pathak, Pranav D. | Mandavgane, Sachin A. | Kulkarni, B. D.
Fruit peels are a rich source of cellulose, hemicellulose, phenolic compounds, and terpenic compounds. Thus, they have the potential to be a novel renewable, sustainable, and low-cost raw material (source) for the production of several value-added products based on framework and concepts such as waste hierarchy that includes biofertilizers, dietary fiber, animal feed, industrial enzymes, substrate for the bioactive compounds production, synthesis of nanomaterials, and clean energy (from residual biomass). With a view of evaluating the environmental burden of biorefinery, a life cycle assessment (LCA) is performed for a representative citrus waste (CW) biorefinery. The functional unit used for LCA was set as 2500 kg of CW processed. The overall GWP was observed to be 937.3 kg CO₂ equivalent per 2500 kg of CW processed. On further analysis of the environmental impact, it was found that different steps contributed significantly, as shown by the various environmental indicator values. Alternative advanced process intensification technologies like microwave and ultrasound-assisted steps replacing the conventional steps when implemented show considerable reduction in environmental indicator values. The variations in the contribution to environmental indicators should be considered during the design and process selection of biorefineries.
Afficher plus [+] Moins [-]Silicic protective surface films for pyrite oxidation suppression to control acid mine drainage at the source
2019
Wang, Shuncai | Zhao, Yue | Li, Shuang
The tailings produce acid mine drainage (AMD) due to sulfide minerals, especially pyrite oxidation. AMD has caused serious pollution to the surrounding aquatic and terrestrial ecosystems because of its famous low pH value and high metal and sulfate concentration, which is an urgent environmental problem faced by the world’s ore mining industry. Here, we show that silicic protective surface films can suppress the oxidation of pyrite-bearing tailings for AMD control at-source without pre-oxidation of pyrite and solution pH adjuster and buffer. We found that the silicic protective surface films formed by calcium silicate can inhibit the oxidation of pyrite-bearing tailings and reduce the production of AMD through chemical leaching tests. Fourier transform infrared (FTIR) analyses and scanning electron microscopy with energy-dispersive spectrometry (SEM/EDS) confirmed the presence of silicic protective surface films of calcium silicate on the surface of pyrite-bearing tailings.
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