Refine search
Results 3251-3260 of 4,937
Intensive tobacco cultivations, a possible public health risk? Full text
2019
Masanotti, Giuseppe Michele | Abbafati, Elia | Petrella, Elena | Vinciguerra, Simone | Stracci, Fabrizio
The cultivation of tobacco has serious consequences for the environment: it impoverishes the soil by assimilating its nutrients, it involves an intensive use of highly polluting pesticides, it perturbs the ecosystem through deforestation, and it releases nicotine into the environment, which is toxic for humans. Italy is the first producer of raw tobacco in Europe and the Valtiberina area is among the most profitable. The first cultivations can be reconducted to the period around 1400. The objective of this experimental work is to verify the sustainability of tobacco cultivation near other crops using nicotine as an indicator. The nicotine on medicinal and wild plants adjacent to tobacco crops has been analyzed, assessing whether it is present or not and which is the concentration. To measure the nicotine present with ultra-high-performance liquid chromatography (UHPLC), LC/MS (liquid chromatography-mass spectrometry) method was used with LOQ (quantification limit) of 0.005 mg/kg. A total of 300 lots of aromatic herbs were sampled, and nicotine was detected in 82.3% of the samples in 2015 and 62.9% in 2016. Furthermore, in 2015, 121 samples of wild material were analyzed, of which 88.4% showed traces of nicotine. These first results indicate a possible potential threat for the population health. This shows that the tobacco cultivation should not be in close proximity to other plantation destined for nutrition, neither for man and nor animals. The elevated impact of nicotine on the ecosystem has negative consequences not only for the economy but it is also a potential public health threat.
Show more [+] Less [-]Comparison of PAH content, potential risk in vegetation, and bare soil near Daqing oil well and evaluating the effects of soil properties on PAHs Full text
2019
Li, Xin | Zheng, Rui | Bu, Qinghua | Cai, Qinghai | Liu, Yufen | Lu, Qian | Cui, Jizhe
As the largest oil field in China, Daqing oil field has been developed in the past six decades. The objectives of this study were to measure the levels of polycyclic aromatic hydrocarbons (PAHs) and assess their ecological risk of PAHs in vegetation soil and bare soil near oil well in Daqing and surrounding soil. Ten sites were selected from two types of soil in grassland: vegetation soil (VS, n = 5) and bare soil (BS, n = 5). The mean concentration of 16 PAHs (∑₁₆ PAHs) was 2240.2 μg/kg. The mean concentrations of eight carcinogenic PAHs (∑₈c PAHs) was 1312.3 μg/kg which accounts for 59% of ∑₁₆ PAHs. The sampling sites had higher proportions of high weight molecular ringed PAHs with higher proportions of benzo (a) pyren (BaP) and benzo (k) fluoranthene (BkF). The main source of PAHs was petroleum, coal/biomass combustion, and vehicular emission in these sampling sites. According to Canadian soil quality guidelines, 60% sites had a significant risk to human health. Moreover, 50% sites had high ecological risk and 30% sites were close to this critical value. Notably, PAH levels were significantly higher in VS than BS; moreover, VS had higher organic matter (OM) content, soil dehydrogenase (sDHA) activity, and lower pH and salt content. A structural equation model was established to explore the effects of soil properties on PAH concentration in VS. The result revealed that OM and sDHA were meaningful to enhance the adsorption and biological fixation of PAHs. This study will provide basic information on PAH level and potential application for phytoremediation.
Show more [+] Less [-]Does economic policy uncertainty matter for carbon emission? Evidence from US sector level data Full text
2019
Jiang, Yong | Zhou, Zhongbao | Liu, Cenjie
Economic policy uncertainty (EPU) will affect the external business environment of economic entities, which in turn affects the decision-making of economic entities. Meanwhile, carbon emissions are closely related to the production decisions of microeconomic entities. Thus, studying the relationship between EPU and carbon emissions helps to clarify the impact of institutional factors behind carbon emissions, which is significant for achieving green development. Based on US sector data, we apply a novel parametric test of Granger causality in quantiles to analyze the relationship between EPU and carbon emissions (its growth and uncertainty). We find that there is an outstanding pattern of Granger-causality from the US EPU to the growth of carbon emissions in the tails of the growth distributions of carbon emissions in the industrial sector, residential sector, electric power sector, and transportation sector, except in the commercial sector. That is, carbon emissions are affected by EPU when the growth of carbon emissions is in a higher or lower growth period. Lastly, we find that the US EPU affects carbon emissions uncertainty over the entire conditional distribution for all sectors.
Show more [+] Less [-]Green is clean: the role of ICT in resource management Full text
2019
Batool, Rubeena | Sharif, Arshian | Islam, Talat | Zaman, Khalid | Shoukry, Alaa Mohamd | Sharkawy, Mohamed A. | Gani, Showkat | Aamir, Alamzeb | Hishan, Sanil S.
It is well documented that carbon emissions can be reduced by replacing conventional energy resources with renewable energy resources; thereby, the role of green technology is essential as it protect natural environment. Given that, the United Nations’ agenda of “green is clean” may be achievable by adoption of green technologies. The objective of the study is to examine the link between information and communication technology (ICT), economic growth, energy consumption, and carbon dioxide (CO₂) emissions in the context of South Korean economy, by using a novel Morlet wavelet approach. The study applies continuous wavelet power spectrum, the wavelet coherency, and the partial and the multiple wavelet coherency to the year during 1973–2016. The outcomes reveal that the connections among the stated variables progress over frequency and time domain. From the frequency domain point of view, the current study discovers noteworthy wavelet coherence and robust lead and lag linkages. From the time-domain sight, the results display robust but not consistent associations among the considered variables. From an economic point sight, the wavelet method displays that ICT helps to reduce environmental degradation in a medium and long run in the South Korean economy. This emphasizes the significance of having organized strategies by the policymakers to cope up with 2 to 3 years of the occurrence of the huge environmental degradation in South Korea.
Show more [+] Less [-]An uptake and elimination kinetics approach to assess the bioavailability of chromium, copper, and arsenic to earthworms (Eisenia andrei) in contaminated field soils Full text
2019
Kilpi-Koski, Johanna | Penttinen, Olli-Pekka | Väisänen, Ari O. | Gestel, Cornelis A. M. van
The aim of this study was to determine the bioavailability of metals in field soils contaminated with chromated copper arsenate (CCA) mixtures. The uptake and elimination kinetics of chromium, copper, and arsenic were assessed in the earthworm Eisenia andrei exposed to soils from a gradient of CCA wood preservative contamination near Hartola, Finland. In soils contaminated with 1480–1590 mg Cr/kg dry soil, 642–791 mg Cu/kg dry soil, and 850–2810 mg Ag/kg dry soil, uptake and elimination kinetics patterns were similar for Cr and Cu. Both metals were rapidly taken up and rapidly excreted by Eisenia andrei with equilibrium reached within 1 day. The metalloid As, however, showed very slow uptake and elimination in the earthworms and body concentrations did not reach equilibrium within 21 days. Bioaccumulation factors (BAF) were low for Cu and Cr (< 0.1), but high for As at 0.54–1.8. The potential risk of CCA exposure for the terrestrial ecosystem therefore is mainly due to As.
Show more [+] Less [-]Degradation of naproxen in chlorination and UV/chlorine processes: kinetics and degradation products Full text
2019
Liu, Yongze | Tang, Yuqing | Wu, Yongxin | Feng, Li | Zhang, Liqiu
Naproxen (NAP) is a nonsteroidal anti-inflammatory drug which has been widely used and frequently detected in water environments. This study investigated the NAP degradation in the chlorination and UV/chlorine disinfection processes, which usually acted as the last barriers for water treatment. The results showed that both chlorination and UV/chlorine disinfection could remove NAP effectively. At various chlorine dosages (0.1~0.5 mM), the contributions of chlorination and reactive radicals to the degradation of NAP in the UV/chlorine process were calculated to be 50.5~56.9% and 43.1~49.5%, respectively. However, the reactive radicals dominated in NAP degradation in alkaline solutions, while chlorination dominated in acidic conditions. The HCO₃⁻ (10~50 mM) slightly inhibited, Cl⁻ (10~50 mM) gradually promoted, and HA (1~5 mg/L) significantly reduced NAP degradation by UV/chlorine process. The degradation intermediates and products were obtained via high-performance liquid chromatography with QE-MS/MS; NAP was degraded by demethylation, acetylation, and dicarboxylic acid pathways during the chlorination and UV/chlorination processes.
Show more [+] Less [-]Protective effect of Zingerone against mouse testicular damage induced by zinc oxide nanoparticles Full text
2019
Rafiee, Zeinab | Khorsandi, Layasadat | Nejad-Dehbashi, Fereshteh
The purpose of the present study was to evaluate the effect of Zingerone (Zing) on zinc oxide nanoparticle (ZNP)-induced spermatogenesis defects in mice. To this end, 50 mg/kg of ZNP was prescribed to the mice as an intoxicated group for 35 days. In protection groups, Zing (10, 20, and 40 mg/kg) was given prior to ZNP treatment for seven days and then co-administration of ZNP for 35 days. Epididymal sperm parameters, testicular histology, Johnsen’s scoring, morphometric parameters, TUNEL staining, oxidative stress, and serum testosterone level were evaluated for determining ZNP and Zing effects on the mouse testicles. Effects of Zing and ZNP on the viability of mouse Leydig (TM3) and mouse Sertoli (TM4) cell lines were also done. Testicular weights, testosterone levels, sperm quality, morphometric parameters, Johnsen’s score, and superoxide dismutase (SOD) and catalase (CAT) activities were significantly decreased in ZNP-intoxicated mice, while apoptotic index, Malondialdehyde (MDA) content, and histological features, including epithelial vacuolization, sloughing, and germ cell detachment, were improved significantly in ZNP-intoxicated mice. Pretreatment with 20 or 40 mg/kg Zing significantly reduced the histological criteria, increased morphometric parameters, enhanced testosterone levels, attenuated apoptotic index, improved sperm quality, and reversed oxidative stress by reducing the level of MDA and incrementing the activity level of SOD and CAT enzymes. Zing dose-dependently enhanced the viability of ZNP-treated TM3 and TM4 cells in comparison with only ZNP-exposed cells. According to the results of our study, Zing effectively prevented the defects in spermatogenesis among mice treated by ZNP.
Show more [+] Less [-]Evaluating the performance of SALTMED model under alternate irrigation using saline and fresh water strategies to winter wheat in the North China Plain Full text
2019
Soothar, Rajesh Kumar | Zhang, Wenying | Zhang, Yanqing | Tankari, Moussa | Mirjat, Uris | Wang, Yaosheng
The effective water management in the North China Plain (NCP) needs a tool to predict winter wheat production due to water quality. A large quantity of brackish water is stored underground in this region, and whether this water can be used properly in agriculture is becoming a crucial issue that is about to be resolved. The SALTMED model is a generic modeling tool for efficient irrigation management strategies, especially for cyclic use of saline and fresh water as well as different water qualities, and it still needs further investigation for alternate irrigation using saline and fresh water at different growth stages of winter wheat. Therefore, the aim of this investigation was to evaluate the performance of SALTMED model and simulate the production of winter wheat grown under different irrigation strategies. Irrigation strategies comprised rain-fed cultivation (NI), fresh and saline water irrigation (FS), saline and fresh water irrigation (SF), saline water irrigation (SS), and fresh water irrigation (FF). Three-year observed data were used for the validations of SALTMED model. The values of evaluation indices of relative error, RMSE, NRMSE, index of agreement (D-index), and R² between simulated and observed grain yield were 6.8%, 0.8, 10.7, 0.9, and 0.9, respectively. The model results supported and matched the observed data and indicated similar differences among the irrigated and rain-fed treatments. It is concluded that the SALTMED model is able to predict grain yield of winter wheat and its productivity under the alternate irrigation using saline and fresh water and their interaction in the climate condition of the NCP.
Show more [+] Less [-]Comparison of extraction techniques for polycyclic aromatic hydrocarbons from lichen biomonitors Full text
2019
Van der Wat, Leandri | Forbes, Patricia B. C.
Lichens are useful biomonitors for atmospheric polycyclic aromatic hydrocarbons (PAHs). Different sample preparation techniques were explored in this regard, including ultrasound-assisted solvent extraction, microwave-assisted extraction, Soxhlet, and the quick, easy, cheap, effective, rugged, and safe (QuEChERS) technique. It was found that a QuEChERS technique using hexane:acetone (1:1, v/v), never reported before for application to lichens, provided the best recoveries of internal standards, the highest total peak area for all PAHs of interest, and %RSDs comparable with the other preparation techniques tested. The optimized sample preparation technique was found to be a comparatively fast method (45 min), with good recoveries (96%), using less solvents and minimal energy consumption. Strong matrix effects were found: both strong enhancement (for the lighter PAHs) and strong suppression (for the heavier PAHs). The use of matrix-matched standards is thus imperative for the accurate determination of PAH concentrations in the lichen samples. Graphical abstract “Note: This data is mandatory. Please provide.”
Show more [+] Less [-]Bibliometric analysis of global research on air pollution and human health: 1998–2017 Full text
2019
Dhital, Sushma | Rupakheti, Dipesh
To give a basic overview of research publications on air pollution and human health, a bibliometric analysis of 2179 documents published during the last two decades (year 1998 to 2017) was carried out. The relevant data was retrieved from the Web of Science Core Collection (WoSCC) and analyzed by using the software such as VOSviewer 1.6.7, Tableau Public 2018.1, and Origin Pro 9.0 for visualization and mapping. The publication trend showed a drastic increase during the second decade. The most productive countries working in the field of air pollution and human health were the USA, China, Italy, England, and Canada, whereas top institutions were Chinese Academy of Sciences, US EPA, Harvard University, Peking University, and University of Sao Paulo. Likewise, leading authors in the context of number of documents published and co-citation were Michael Bell and C. Arden Pope respectively. Majority of the researches were published in the journals like Atmospheric Environment, Science of the Total Environment, and Environmental Science and Pollution Research whereas most common author keywords in the publications were “air pollution,” “particulate matter,” and “PM₂.₅.”
Show more [+] Less [-]