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Does the air condition system in busses spread allergic fungi into driver space? Full text
2018
Sowiak, Małgorzata | Kozajda, Anna | Jeżak, Karolina | Szadkowska-Stańczyk, Irena
The aim of this study was to establish whether the air-conditioning system in buses constitutes an additional source of indoor air contamination with fungi, and whether or not the fungi concentration depends on the period from the last disinfection of the system, combined with replacement of the cabin dust particle filter. The air samples to fungi analysis using impact method were taken in 30 buses (20 with an air-conditioning system, ACS; 10 with a ventilation system, VS) in two series: 1 and 22 weeks after cabin filter replacement and disinfection of the air-conditioning system. During one test in each bus were taken two samples: before the air-conditioning or ventilation system switched on and 6 min after operating of these systems. The atmospheric air was the external background (EB). After 1 week of use of the system, the fungi concentrations before starting of the ACS and VS system were 527.8 and 1053.0 cfu/m³, respectively, and after 22 weeks the concentrations were 351.9 and 1069.6 cfu/m³, respectively. While in the sample after 6 min of ACS and VS system operating, the fungi concentration after 1 week of use was 127.6 and 233.7 cfu/m³, respectively, and after 22 weeks it was 113.3 and 324.9 cfu/m³, respectively. Results do not provide strong evidence that air-conditioning system is an additional source of indoor air contamination with fungi. A longer operation of the system promoted increase of fungi concentration in air-conditioned buses only.
Show more [+] Less [-]Connecting gastrointestinal cancer risk to cadmium and lead exposure in the Chaoshan population of Southeast China Full text
2018
Cadmium (Cd) and lead (Pb) pose a serious threat to human health because of its carcinogenicity. China ranks first according to the Global Cancer Report for 2014 in newly diagnosed gastrointestinal cancers and cancer deaths. The aim of the present study was to evaluate the association of Cd and Pb burden with the risk of gastrointestinal cancers in a hospital-based case-control study from southern regions of China, Chaoshan area. A total of 279 hospitalized patients were recruited in this study, of which 167 were gastrointestinal cancer cases (70 esophageal cancer, 51 gastric cancer, and 46 colorectal cancer), and 112 controls were recruited from two hospitals in the Chaoshan area of southeast China. Basic clinical data and information on gender, age, and other demographic characteristics were collected from medical records. Blood Cd and Pb levels were detected by graphite furnace atomizer absorption spectrophotometry (GFAAS). Blood Cd/Pb levels and over-limit ratios between cases and controls were compared by Mann-Whitney U and Kruskal-Wallis H tests. We used logistic regression to estimate odds ratios (ORs) as measures of relative risk and explored the relationships between blood Cd/Pb levels and gastrointestinal cancer risk and clinicopathological characteristics. Median levels of blood Cd and Pb in cases (2.12 and 60.03 μg/L, respectively) were significantly higher than those of controls (1.47 and 53.84 μg/L, respectively). The over-limit ratios for Cd (≥ 5 μg/L) and Pb (≥ 100 μg/L) in the cases were both higher than that of controls. Blood Cd levels had a tendency to accumulate in the human body with gender, age, and tobacco smoking, while blood Pb levels only were associated with tobacco smoking. The logistic regression model illustrated that gastrointestinal cancers were significantly associated with blood Cd levels and blood Pb levels. The concentrations of Cd and Pb in patients with T3 + T4 stage were markedly higher than in patients with T1 + T2. On the other hand, blood Cd levels were dramatically increased in the distant –metastasis (M1). Blood Cd and Pb levels are significantly higher in gastrointestinal cancers compared to controls. Cd and Pb appear to be risk factors for gastrointestinal cancers in Chaoshan region, and higher levels of Cd and Pb may promote the occurrence and progression of gastrointestinal cancers.
Show more [+] Less [-]Environmental impact assessment of municipal solid waste management options using life cycle assessment: a case study Full text
2018
Yadav, Pooja | Samadder, SukhaRanjan
The goal of this study is to use life cycle assessment (LCA) tool to assess possible environmental impacts of different municipal solid waste management (MSWM) scenarios on various impact categories for the study area Dhanbad City, India. The scenarios included in the present study are collection and transportation (denoted as S1); baseline scenario consisting of recycling, open burning, open dumping, and finally unsanitary landfilling without energy recovery (denoted by S2); composting and landfilling (denoted by S3); and recycling and composting followed by landfilling of inert waste without energy recovery (denoted by S4). One ton of municipal solid waste (MSW) was selected as the functional unit. The primary data were collected through sampling, surveys, and literatures. Background data were obtained from Eco-invent data of SimaPro 8.1 libraries. The scenarios were compared using the CML 2 baseline 2000 method, and the results indicated that the scenario S1 had the highest impact on marine aquatic ecotoxicity (1.86E + 04 kg 1,4-DB eq.) and abiotic depletion (2.09E + 02 kg Sb eq.). S2 had the highest impact on global warming potential (9.42E + 03 kg CO₂ eq.), acidification (1.15E + 01 kg SO₂ eq.), eutrophication (2.63E + 00 kg PO₄³⁻ eq.), photochemical oxidation (2.12E + 00 kg C₂H₄ eq.), and human toxicity (2.25E + 01 kg 1,4-DB eq.). However, S3 had the highest impact on abiotic depletion (fossil fuels) (2.71E + 02 MJ), fresh water aquatic ecotoxicity (6.54E + 00 kg 1,4-DB eq.), terrestrial ecotoxicity (3.36E − 02 kg 1,4-DB eq.), and ozone layer depletion (2.73E − 06 kg CFC-11 eq.). But S4 did not have the highest impact on any of the environmental impact categories due to recycling of packaging waste and landfilling of inert waste. Landfilling without energy recovery of mixed solid waste was found as the worst disposal alternative. The scenario S4 was found as the most environmentally suitable technology for the study area and recommended that S4 should be considered for strategic planning of MSWM for the study area.
Show more [+] Less [-]Review on applications of artificial intelligence methods for dam and reservoir-hydro-environment models Full text
2018
Allawi, MohammedFalah | Jaafar, Othman | Mohamad Hamzah, Firdaus | Abdullah, SharifahMastura Syed | El-shafie, Ahmed
Efficacious operation for dam and reservoir system could guarantee not only a defenselessness policy against natural hazard but also identify rule to meet the water demand. Successful operation of dam and reservoir systems to ensure optimal use of water resources could be unattainable without accurate and reliable simulation models. According to the highly stochastic nature of hydrologic parameters, developing accurate predictive model that efficiently mimic such a complex pattern is an increasing domain of research. During the last two decades, artificial intelligence (AI) techniques have been significantly utilized for attaining a robust modeling to handle different stochastic hydrological parameters. AI techniques have also shown considerable progress in finding optimal rules for reservoir operation. This review research explores the history of developing AI in reservoir inflow forecasting and prediction of evaporation from a reservoir as the major components of the reservoir simulation. In addition, critical assessment of the advantages and disadvantages of integrated AI simulation methods with optimization methods has been reported. Future research on the potential of utilizing new innovative methods based AI techniques for reservoir simulation and optimization models have also been discussed. Finally, proposal for the new mathematical procedure to accomplish the realistic evaluation of the whole optimization model performance (reliability, resilience, and vulnerability indices) has been recommended.
Show more [+] Less [-]The effect of innovation on CO2 emissions of OCED countries from 1990 to 2014 Full text
2018
Human activities are accelerating CO₂ emissions all over the world most especially in high-income nations, spurring the rise in greenhouse gas emissions. For decades, technologies have been developed and patented in response to the environmental problems. There is an outcry for innovative ways to combat the environmental menace. This attests to the enormity of research being done, in recent years, to investigate how innovation can help mitigate CO₂ emissions. This research aims at investigating into the effect of innovation on CO₂ emissions in 28 OCED countries at an individual level for the recent period 1990 to 2014. The source of data for our utilized variables is the World Bank Indicators. Our study employed three key models based on the STIRPAT model, the economic-EKC growth model, and the innovation-EKC model. The findings of our study revealed that innovation plays a key role towards mitigation of CO₂ emissions in most OECD countries. Its impact, however, varies across the countries, depending on some key factors and channels elucidated in this paper. Additionally, our study asserts that improvement in GDP per capita leads to the rise in CO₂ in most OECD economies, although mitigate emissions in few OECDs; hence, the economic-EKC model is not valid for most economies. Non-renewable energy accelerates emissions whiles renewable energy sources mitigate emissions. Research and development (R&D) improves environmental quality and the EKC for both economic growth and innovation, valid for a few economies of the OECDs. We conclude that innovation is necessary in mitigating CO₂ emissions; hence, governments and policy makers should invest and promote innovative renewable energy sources.
Show more [+] Less [-]Climate change and economic growth: a heterogeneous panel data approach Full text
2018
Sequeira, Tiago Neves | Santos, Marcelo Serra | Magalhães, Manuela
Climate change is a global phenomenon. Its impact on economic growth must therefore be analyzed in accordance with its (time-varying) common effects. We present an econometric analysis that evaluates this effect taking into account its global nature. Contrary to previous evidence that ignores the global effects, we obtain that the rising temperature has not decreased growth in real GDP per capita in the second half of the twentieth century for the world countries. However, we obtain a negative effect of rising temperatures and a positive effect of rising precipitation in poor countries. This positive effect of rising precipitation is also confirmed for hot and temperate countries.
Show more [+] Less [-]Facile synthesis of magnetic disinfectant immobilized with silver ions for water pathogenic microorganism’s deactivation Full text
2018
Elwakeel, Khalid Z. | El-Liethy, Mohamed Azab | Ahmed, Mohammad S. | Ezzat, Saeid M. | Kamel, Mohamed M.
One-pot synthesis of a new magnetic disinfectant was achieved through the polymerization of thiourea and formaldehyde in the presence of magnetite nanoparticles (MTUF). The obtained magnetic chelating resin was loaded with Ag(I) ions. This material was tested as a disinfectant for water pathogenic microorganism’s deactivation. The toxicity of MTUF before and after Ag(I) loading was estimated. The antimicrobial activity tests of MTUF-Ag were carried out against Escherichia coli, Salmonella Typhimurium, and Pseudomonas aeruginosa as examples of Gram-negative bacteria; Listeria monocytogenes, Staphylococcus aureus, Enterococcus faecalis, and Bacillus subtilis as examples of Gram-positive bacteria; and Candida albicans as representative for fungi. The results showed that the minimum inhibitory dosage (MID) of MTF-Ag against Escherichia coli, Salmonella Typhimurium, Listeria monocytogenes, Staphylococcus aureus, and mixed culture were 1.5, 2.0, 1.0, 1.5, and 1.5 mg/mL, respectively, after 40 min of contact time. While C. albicans was more resistant to the magnetic disinfectant, only three log reductions were done at 2.5 mg/mL. The studied MTUF-Ag was successfully tested for water and wastewater pathogenic microorganism’s deactivation. It can be concluded that MTUF-Ag could be a good candidate for water disinfection.
Show more [+] Less [-]Responses of magnetic properties to heavy metal pollution recorded by lacustrine sediments from the Lugu Lake, Southwest China Full text
2018
Environmental magnetism, which is rapid, sensitive, economical, and non-destructive, has been used to assess heavy metal pollution in lake sediments based on the relationships between magnetic properties and heavy metal concentrations. We conducted a systematic environmental magnetic and heavy metal study of the sediments of the core LGS from Lugu Lake in Southwest China. The results show that the concentration-related magnetic parameters (χ, χARM, and SIRM) in the core LGS showed an increasing trend from bottom to top. The results of rock magnetism indicated that the dominant magnetic particles were magnetite. Two sources of magnetic minerals can be distinguished by the correlations of χ vs. χfd% and χ vs. χARM/χ: the surrounding catchment and anthropogenic activities. In addition, Pearson correlation analysis and principal component analysis showed that the concentration-dependent magnetic parameters have significant correlations with heavy metal (Al, Ti, Fe, Cr, Ni, Cu, Zn, and Cd) concentrations as well as the Tomlinson pollution load index (PLI), indicating that there are essential linkages of sources, deposition, and migration between magnetic particles and heavy metals. Based on previously reported ¹³⁷Cs and ²¹⁰Pb data, the historical trends of heavy metal pollution in Lugu Lake were successfully reconstructed, and the causes of heavy metal pollution were mainly agricultural practices and atmospheric metal depositions from anthropogenic sources. The significant correlations between magnetic parameters, heavy metals, and the PLI indicate that magnetic parameters can potentially be used as an index of heavy metal pollution in lacustrine deposits.
Show more [+] Less [-]The impacts of environmental governance on political turnover of municipal party secretary in China Full text
2018
Feng, Gen-Fu | Dong, Minyi | Wen, Jun | Chang, Chun-Ping
Political incentive is one of the most efficient methods to promote local officials to push for both economic growth and environmental progress in the context of China. Since previous scholars have never investigated the relationships between political turnover and environmental governance at the municipal level, in this work, we proxy pollution by SO₂, COD, SOOT, and NHx and examine whether environmental performance affects the political turnover of the municipal party secretary by exploiting a panel conditional logit with a fixed-effect model for the period 2002–2013. The results indicate that environmental performance does not significantly impact the turnover of municipal party secretaries, offering evidence that an increase of SO₂ is associated with the likelihood of promotion under the panel multinomial logit approach. However, a higher GDP growth rate plays the determinant factor affecting the promotion of China’s municipal party secretaries. Specific policy recommendations are proposed in accordance with our empirical findings.
Show more [+] Less [-]Biochemical and morphological biomarkers of the liver damage in the Neotropical fish, Piaractus mesopotamicus, injected with crude extract of cyanobacterium Radiocystis fernandoi Full text
2018
Tavares, Driele | Paulino, MarceloGustavo | Terezan, AnaPaula | Fernandes, JoãoBatista | Giani, Alessandra | Fernandes, MarisaNarciso
Cyanobacterial proliferation in river and lakes is the result of eutrophication. The cyanobacterium Radiocystis fernandoi strain R28 produces mostly two MC variants MC-RR and MC-YR and small amounts of other oligopeptides, but does not produce MC-LR. The present study investigated the hepatotoxic potential of the crude extract of the R. fernandoi strain R28 on the Neotropical fish, Piaractus mesopotamicus, at 3, 6, and 24 h after intraperitoneal injection (100 μg MC-LR equivalent per kg⁻¹ body mass) using biochemical and morphological biomarkers of liver damage. Although the protein phosphatases PP1 and PP2A were not inhibited during the 24-h treatment, liver parenchyma and hepatocyte structure were disrupted. Alkaline phosphatase increased at 3 h post-injection and decreased after 24 h; alanine aminotransferase and aspartate aminotransferase increased in a time-dependent manner up to 24 h indicating impaired liver function. Progressive histopathological changes were consistent with biochemical results demonstrating alterations in liver structure and function. In conclusion, the crude extract of R. fernandoi strain R28 has high hepatotoxic potential and can severely compromise fish health.
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