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Association between coal consumption and urbanization in a coal-based region: a multivariate path analysis Full text
2018
Guo, Xiaojia | Zhang, Zilong | Zhao, Rui | Wang, Guokui | Xi, Jing
This study examines causal relationship between urbanization and coal consumption. By taking Shanxi Province, China, as a typical case area, a multivariate path analysis model is used to seek for the key driving factors of coal consumption throughout its urbanization during the period of 1978 to 2014. The result indicates that the key factors are urban household disposable income and residential area per capita, which are closely related to urban construction and household lifestyle. It is expected that the study may inform better policies on coal consumption reduction and energy structure improvement.
Show more [+] Less [-]Deciphering the growth, organic acid exudations, and ionic homeostasis of Amaranthus viridis L. and Portulaca oleracea L. under lead chloride stress Full text
2018
Javed, MuhammadTariq | Akram, MuhammadSohail | Habib, Noman | Tanwir, Kashif | Qāsim ʻAlī Nīshāpūrī, | Niazi, NabeelKhan | Gul, Huma | Iqbal, Naeem
Lead (Pb) stress adversely affects in planta nutrient homeostasis and metabolism when present at elevated concentration in the surrounding media. The present study was aimed at investigation of organic acid exudations, elemental contents, growth, and lipid peroxidation in two wild plants (Amaranthus viridis L. and Portulaca oleracea L.), exhibiting differential root to shoot Pb translocation, under Pb stress. Plants were placed in soil spiked with lead chloride (PbCl₂) concentrations of 0, 15, 30, 45, or 60 mg Pb/kg soil, in rhizoboxes supplied with nylon nets around the roots. The plant mucilage taken from root surfaces, mirroring the rhizospheric solution, was analyzed for various organic acids. Lead stress resulted in a release of basified root exudates from both plants. Exudates of P. oleracea roots showed a higher pH. In both plants, the pH rising effect was diminished at the highest Pb treatment level. The exudation of citric acid, glutamic acid (in both plants), and fumaric acid (in P. oleracea only) was significantly increased with applied Pb levels. In both plant species, root and shoot Pb contents increased while nutrients (Ca, Mg, and K) decreased with increasing Pb treatment levels, predominantly in A. viridis. At 60 mg Pb/kg soil, shoot Na content of A. viridis was significantly higher as compared to untreated control. Higher Pb treatment levels decreased plant fresh and dry masses as well as the quantity of photosynthetic pigments due to enhanced levels of plant H₂O₂ and thiobarbituric acid reactive substances in both species. Photosynthetic, growth, and oxidative stress parameters were grouped into three distinct dendrogram sections depending on their similarities under Pb stress. A positive correlation was identified between Pb contents of studied plants and secretion of different organic acids. It is concluded that Pb stress significantly impaired the growth of A. viridis and P. oleracea as a result of nutritional ion imbalance, and the response was cultivar-specific and dependent on exogenous applied Pb levels. Differential lipid oxidation, uptake of nutrients (Ca, Mg, and K) and exudation of citric acid, fumaric acid, and glutamic acid could serve as suitable physiological indicators for adaptations of P. oleracea to Pb enriched environment. The findings may help in devising strategies for Pb stabilization to soil colloids.
Show more [+] Less [-]Associations between respiratory health and ambient air quality in Canakkale, Turkey: a long-term cohort study Full text
2018
Mentese, Sibel | Bakar, Coskun | Mirici, NihalArzu | Oymak, Sibel | Otkun, MuserrefTatman
Few epidemiological studies investigating the association between air pollution and health are available in Turkey. The aim of this cohort-type study is to examine the relationships between ambient air quality, respiratory diseases, and decreases in pulmonary function over a year in three different towns in Canakkale: Canakkale Central town (region I), Lapseki town center (region II), and Can town (region III). Region III had four different sub-regions, which were Can town center (region III-A), and the villages located around Can town, namely Durali (region III-B), Kulfal (region III-C), and Yuvalar (region III-D). In the first stage of the study, a detailed questionnaire was completed by the participants (n = 1152) in face-to-face interviews and pulmonary function test (PFT) was performed. In the second stage of the study, PFT measurements were repeated 1 year after the first stage. Particulate matter, SO₂, NO₂, and ozone were gathered from air quality monitoring stations located in the centers of the three regions. The most polluted area was region III, while region I and region II were the least polluted areas. The risk of pulmonary function decline throughout a year was 2.1 times higher in region III, 2.4 times higher both in regions III-B and III-C, and 1.6 times higher for smokers in all regions. In the present study, ambient air quality was worse in region III (industrialized region), which influenced PFT scores and the prognostics for chronic respiratory diseases. The findings of this study should be considered for future investment plans in this region related to human and environmental health needs.
Show more [+] Less [-]Spatial distribution and potential biological risk of some metals in relation to granulometric content in core sediments from Chilika Lake, India Full text
2018
Barik, SarojaK. | Muduli, PradiptaR. | Mohanty, Bita | Rath, Prasanta | Samanta, Srikanta
The article presents first systematic report on the concentration of selected major elements [iron (Fe) and manganese (Mn)] and minor elements [zinc (Zn), copper (Cu), chromium (Cr), lead (Pb), nickel (Ni), and cobalt (Co)] from the core sediment of Chilika Lake, India. The analyzed samples revealed higher content of Pb than the background levels in the entire study area. The extent of contamination from minor and major elements is expressed by assessing (i) the metal enrichments in the sediment through the calculations of anthropogenic factor (AF), pollution load index (PLI), Enrichment factor (EF), and geoaccumulation index (Igeo) and (ii) potential biological risks by the use of sediment quality guidelines like effect range median (ERM) and effect range low (ERL) benchmarks. The estimated indices indicated that sediment is enriched with Pb, Ni, Cr, Cu and Co. The enrichment of these elements seems to be due to the fine granulometric characteristics of the sediment with Fe and Mn oxyhydroxides being the main metal carriers and fishing boats using low grade paints, fuel, and fishing technology using lead beads fixed to fishing nets. Trace element input to the Chilika lake needs to be monitored with due emphasis on Cr and Pb contaminations since the ERM and ERL benchmarks indicated potential biological risk with these metals.
Show more [+] Less [-]Combining hydrogen peroxide addition with sunlight regulation to control algal blooms Full text
2018
Zhou, Qichao | Li, Lin | Huang, Licheng | Guo, Liangliang | Song, Lirong
The concentration, light conditions during treatment, and the number of hydrogen peroxide (H₂O₂) additions as well as the H₂O₂ treatment combined with subsequent shading to control algal blooms were studied in the field (Lake Dianchi, China). The cyanobacterial stress and injury due to H₂O₂ were dose dependent, and the control effectiveness and degradation of H₂O₂ were better and faster under full light than under shading. However, H₂O₂ was only able to control a bloom for a short time, so it may have promoted the recovery of algae and allowed the biomass to rebound due to the growth of eukaryotic algae. A second addition of H₂O₂ at the same dose had no obvious effect on algal control in the short term, suggesting that a higher concentration or a delayed addition should be considered, but these alternative strategies are not recommended so that the integrity of the aquatic ecosystem is maintained and algal growth is not promoted. Moreover, shading (85%) after H₂O₂ addition significantly reduced the algal biomass during the enclosure test, no restoration was observed for nearly a month, and the proportion of eukaryotic algae declined. It can be inferred that algal blooms can be controlled by applying a high degree of shading after treatment with H₂O₂.
Show more [+] Less [-]Single and combined metal contamination in coastal environments in China: current status and potential ecological risk evaluation Full text
2018
Manzoor, Romana | Zhang, Tingwan | Zhang, Xuejiao | Wang, Min | Pan, Jin-Fen | Wang, Zhumei | Zhang, Bo
With the development of industrialization and urbanization, metal and metalloid pollution is one of the most serious environmental problems in China. Current contamination status of metals and metalloid and their potential ecological risks along China’s coasts were reviewed in the present paper by a comprehensive study on metal contents in marine waters and sediments in the past few decades. The priority metals/metalloid cadmium (Cd), mercury (Hg), chromium (Cr), lead (Pb), and arsenic (As), which were the target elements of the designated project “Comprehensive Prevention and Control of Heavy Metal Pollution” issued by the Chinese government in 2011, were selected considering their high toxicity, persistence, and prevalent existence in coastal environment. Commonly used environmental quality evaluation methods for single and combined metals were compared, and we accordingly suggest the comprehensive approach of joint utilization of the Enrichment Factor and Effect Range Median combined with Pollution Load Index and Mean Effect Range Median Quotient (EEPME); this battery of guidelines may provide consistent, internationally comparable, and accurate understanding of the environment pollution status of combined metals/metalloid and their potential ecological risk.
Show more [+] Less [-]Lead facilitates foci formation in a Balb/c-3T3 two-step cell transformation model: role of Ape1 function Full text
2018
Hernández-Franco, Pablo | Silva, Martín | Franco, Rodrigo | Valverde, Mahara | Rojas, Emilio
Several possible mechanisms have been examined to gain an understanding on the carcinogenic properties of lead, which include among others, mitogenesis, alteration of gene expression, oxidative damage, and inhibition of DNA repair. The aim of the present study was to explore if low concentrations of lead, relevant for human exposure, interfere with Ape1 function, a base excision repair enzyme, and its role in cell transformation in Balb/c-3T3. Lead acetate 5 and 30 μM induced APE1 mRNA and upregulation of protein expression. This increase in mRNA expression is consistent throughout the chronic exposure. Additionally, we also found an impaired function of Ape1 through molecular beacon-based assay. To evaluate the impact of lead on foci formation, a Balb/c-3T3 two-step transformation model was used. Balb/c-3T3 cells were pretreated 1 week with low concentrations of lead before induction of transformation with n-methyl-n-nitrosoguanidine (MNNG) (0.5 μg/mL) and 12-O-tetradecanoylphorbol-13-acetate (TPA) (0.1 μg/mL) (a classical two-step protocol). Morphological cell transformation increased in response to lead pretreatment that was paralleled with an increase in Ape1 mRNA and protein overexpression and an impairment of Ape1 activity and correlating with foci number. In addition, we found that lead pretreatment and MNNG (transformation initiator) increased DNA damage, determined by comet assay. Our data suggest that low lead concentrations (5, 30 μM) could play a facilitating role in cellular transformation, probably through the impaired function of housekeeping genes such as Ape1, leading to DNA damage accumulation and chromosomal instability, one of the most important hallmarks of cancer induced by chronic exposures.
Show more [+] Less [-]Measuring heavy metal stress in ryegrass using helium-cadmium excitation-based photoluminescence Full text
2018
Cheng, Jiemin | Lv, Yan | Yu, Yaqin | Li, Xinrui | Sun, Zihan
As the chemical analysis of heavy metal uptake and toxicity in plants is time-consuming, expensive, and destructive, a simple and reliable method for detecting heavy metal transfer from the soil to plants is thus necessary. We aimed to measure copper (Cu), lead (Pb), and cadmium (Cd) stress in ryegrass in vivo using plant photoluminescence based on a helium (He)-cadmium excitation source (wavelength 325 nm). The soils were combined with Cu, Pb and Cd, respectively. Fifteen ryegrass seedlings (Lolium multiflorum) were planted in each pot. After 30 days, leaves from seedlings at the fourth-leaf stage were collected and the fluorescence excitation spectra were detected using a He-Cd laser at an excitation wavelength of 325 nm. Three emission peaks that constitute known chlorophyll wavelengths, namely 450, 690, and 735 nm, were detected. These three peaks were strongly influenced by Cu, Pb, and Cd concentrations in the soil. Higher peak heights at 450 nm were observed with increasing Cu, Pb, and Cd concentrations in the soil, whereas no changes were noted at 690 and 735 nm. The P450/P690 and P450/P735 ratios were positively correlated with Cu, Pb, and Cd soil concentrations, ryegrass uptake, and DTPA-extractable Cu, Pb, and Cd in the soil. The related coefficients were all greater than 0.9. However, no correlation between the P690/P735 ratio, Cu, Pb, and Cd ryegrass uptake, and DTPA-extractable Cu, Pb, and Cd in the soil was observed. The measurement of plant photoluminescence in vivo using a He-Cd excitation source (wavelength 325 nm) may be utilized as an approach for monitoring the response of plants to specific stressors.
Show more [+] Less [-]Degradation reaction of Diazo reactive black 5 dye with copper (II) sulfate catalyst in thermolysis treatment Full text
2018
Lau, Yen-Yie | Wong, Yee-Shian | Ang, Tze-Zhang | Ong, Soon-An | Lutpi, NabilahAminah | Ho, Li-Ngee
The theme of present research demonstrates performance of copper (II) sulfate (CuSO₄) as catalyst in thermolysis process to treat reactive black 5 (RB 5) dye. During thermolysis without presence of catalyst, heat was converted to thermal energy to break the enthalpy of chemical structure bonding and only 31.62% of color removal. With CuSO₄ support as auxiliary agent, the thermally cleaved molecular structure was further destabilized and reacted with CuSO₄. Copper ions functioned to delocalize the coordination of π of the lone paired electron in azo bond, C=C bond of the sp² carbon to form C-C of the sp³ amorphous carbon in benzene and naphthalene. Further, the radicals of unpaired electrons were stabilized and RB 5 was thermally decomposed to methyl group. Zeta potential measurement was carried out to analyze the mechanism of RB 5 degradation and measurement at 0 mV verified the critical chemical concentration (CCC) (0.7 g/L copper (II) sulfate), as the maximum 92.30% color removal. The presence of copper (II) sulfate catalyst has remarkably increase the RB 5 dye degradation as the degradation rate constant without catalyst, k₁ is 6.5224 whereas the degradation rate constant with catalyst, k₂ is 25.6810. This revealed the correlation of conversion of thermal energy from heat to break the chemical bond strength, subsequent fragmentation of RB 5 dye molecular mediated by copper (II) sulfate catalyst. The novel framework on thermolysis degradation of molecular structure of RB 5 with respect to the bond enthalpy and interfacial intermediates decomposition with catalyst reaction were determined.
Show more [+] Less [-]Environmental pollutants, pathogens and immune system in earthworms Full text
2018
Ghosh, Shyamasree
Earthworms also known as farmer’s friends are natural tillers of soil. They belong to Phylum Annelida and class Oligochaeta. Acid soils with organic matter and surface humus maintain the largest fauna of worms and earthworms. Due to their habitat in soil, they are constantly exposed to microbes and pollution generated by anthropogenic sources. Studies have revealed that damage of the immune system of earthworms can lead to alterations of both morphological and cellular characteristics of worms, activation of signalling pathways and can strongly influence their survival. Therefore, the understanding of the robust immune system in earthworms has become very important from the point of view of understanding its role in combating pathogens and pollutants and its role in indicating the soil pollution. In this article, we have outlined the (i) components of the immune system and (ii) their function of immunological responses on exposure to pollutants and pathogens. This study finds importance from the point of view of ecotoxicology and monitoring of earthworm health and exploring the scope of earthworm immune system components as biomarkers of pollutants and environmental toxicity. The future scope of this review remains in understanding the earthworm immunobiology and indicating strong biomarkers for pollution.
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