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Inter-comparison of carbon content in PM10 and PM2.5 measured with two thermo-optical protocols on samples collected in a Mediterranean site Full text
2019
Merico, Eva | Cesari, Daniela | Dinoi, Adelaide | Gambaro, Andrea | Barbaro, Elena | Guascito, Maria R. | Giannossa, Lorena C. | Mangone, Annarosa | Contini, Daniele
Scientific interest is focusing on different approaches for characterising organic carbon (OC), elemental carbon (EC) and equivalent black carbon (eBC), although EUSAAR2 protocol has been established and frequently used in EU for regulatory purposes. Discrepancies are observed due to thermal protocols used for OC/EC determinations and the effect of the chemical-physical properties of aerosol using optical measurements for eBC. In this work, a long-term inter-comparison of carbon measurements with two widely used protocols (EUSAAR2 and NIOSH870) was performed on PM₂.₅ and PM₁₀ samples. The influence of the protocol on the evaluation of secondary organic aerosol (SOC) and on the correlation between EC and eBC was investigated. An extensive check of repeatability gave typical uncertainties of ~ 5% for TC and OC, and ~ 10% for EC for both thermal protocols. Results show that OC is statistically comparable between the two protocols but EC is significantly higher with EUSAAR2, especially during the warm season. The ratio OC/EC is lower with EUSAAR2, also showing a seasonality (lower values in the warm season) not observed with NIOSH870. Despite the differences in OC/EC ratios, the contribution of SOC to OC (~ 50%), evaluated using the EC-tracer method, did not differ significantly between the two protocols and for both size fractions. Further, SOC/OC ratios were comparable in cold and warm periods. eBC/EC ratios larger than one for both protocols were obtained, 1.62 (EUSAAR2) and 1.92 (NIOSH870), and also correlated with the ratio OC/EC for both protocols, especially in the cold season.
Show more [+] Less [-]Fracking and infant mortality: fresh evidence from Oklahoma Full text
2019
Apergis, Nicholas | Hayat, Tasawar | Saeed, Tareq
This paper explores the impact of shale gas and oil fracking wells on infants’ health at birth across Oklahoma counties. The empirical analysis makes use of the Dumitrescu-Hurlin causality test, as well as the (long-run) Pooled Mean Group method. The results clearly document that there is a unidirectional relationship between fracking activities and three alternative indexes of infants’ health at birth, as well as a significant impact of fracking on infants’ health indicators. In addition, the results illustrate the substantial role of fracking through the drinking water quality channel.
Show more [+] Less [-]Assessment of air pollution and health hazard associated with sawmill and municipal waste burning in Abeokuta Metropolis, Nigeria Full text
2019
Oguntoke, Olusegun | Emoruwa, Folayemi O. | Taiwo, Matthew A.
Indiscriminate disposal and open burning of sawmill and municipal solid wastes constitute hazards to the quality of the immediate environment and human health. This study assessed the levels of pollutants emitted by burning sawmill and municipal wastes, and their potential hazards. Nine selected sawmills and 6 municipal solid-waste dumps in Abeokuta metropolis were investigated. During waste burning, the concentrations of NO₂, SO₂, CO, H₂S, NH₃ and VOC were monitored in replicates at the dumpsites, 10 m, 20 m and the nearest houses using portable samplers (Aeroqual and Multi-RAE). Mean, ANOVA, correlation and regression statistical tools were used to analyse air quality data; air quality index (AQI) was employed to classify the hazard rating of the gaseous pollutants. Nearest neighbour analysis in ArcGIS 10.0 was used to investigate dumpsites location pattern within the city. The concentrations (mg/m³) of sampled parameters from source to nearest house (NH) at the dumpsites ranged as follows: < 0.002–0.175 (NO₂), < 0.002–0.235 (SO₂), 0.065–0.425 (H₂S), 13.98–47.40 (CO), 6.74–170.41 (NH₃) and 31.13–820.03 (VOC) in wet and dry seasons. The mean concentrations of NO₂, SO₂ and VOC were below permissible limits at most locations while CO values were higher at all dumpsite. Significant variations (p < 0.05) were observed in the concentrations of the monitored parameters except NO₂ values (SMW) in dry season. AQI rated NO₂ and SO₂ concentrations as “good” at all sites while CO emission ranged from unhealthy to hazardous across the dumpsites. In conclusion, the present locations of SMW and MSW dumps in the city degrade environmental quality and are unsafe for human health.
Show more [+] Less [-]The impact of urban pollution on metal contamination of selected forest pockets in Cape Town, South Africa Full text
2019
Krüger, Anne-Liese | Snyman, Reinette | Odendaal, James
Urban forests are exposed to metals, such as manganese, copper, and zinc in the atmosphere that originate from anthropogenic activities, that include vehicle-related traffic, industries, construction sites, fossil fuel burning for heating and cooking purposes, and resuspension processes related to urban surfaces. Not only is the rich biodiversity of plant and animal species in forests under threat, but so are the biodiversity of soil, sustaining ecosystem functions, as well as human health. The objective of this study was therefore to determine the concentrations of manganese, copper, and zinc arising from urban, industrial, and traffic-related pollution in the remote and/or untouched urban indigenous forests using soil, leaf litter, and key forest organisms (mosses, lichens, and millipedes) in three forests (Platbos, Orange Kloof, and Newlands) in the Western Cape, South Africa. Elevated concentrations of these metals were found in the forests closest to the city, as well as at sites in close proximity of vehicle traffic.
Show more [+] Less [-]Development of hybrid processes for the removal of volatile organic compounds, plasticizer, and pharmaceutically active compound using sewage sludge, waste scrap tires, and wood chips as sorbents and microbial immobilization matrices Full text
2019
de Toledo, Renata Alves | Hin Chao, U. | Shen, Tingting | Lu, Qihong | Li, Xueqing | Shim, Hojae
This study evaluated the reutilization of waste materials (scrap tires, sewage sludge, and wood chips) to remove volatile organic compounds (VOCs) benzene/toluene/ethylbenzene/xylenes/trichloroethylene/cis-1,2-dichloroethylene (BTEX/TCE/cis-DCE), plasticizer di(2-ethylhexyl) phthalate (DEHP), and pharmaceutically active compound carbamazepine from artificially contaminated water. Different hybrid removal processes were developed: (1) 300 mg/L BTEX + 20 mg/L TCE + 10 mg/L cis-DCE + tires + Pseudomonas sp.; (2) 250 mg/L toluene + sewage sludge biochar + Pseudomonas sp.; (3) 100 mg/L DEHP + tires + Acinetobacter sp.; and (4) 20 mg/L carbamazepine + wood chips + Phanerochaete chrysosporium. For the hybrid process (1), the removal of xylenes, TCE, and cis-DCE was enhanced, resulted from the contribution of both physical adsorption and biological immobilization removal. The hybrid process (2) was also superior for the removal of DEHP and required a shorter time (2 days) for the bioremoval. For the process (3), the biochar promoted the microbial immobilization on its surface and substantially enhanced/speed up the bioremoval of toluene. The fungal immobilization on wood chips in the hybrid process (4) also improved the carbamazepine removal considerably (removal efficiencies of 61.3 ± 0.6%) compared to the suspended system without wood chips (removal efficiencies of 34.4 ± 1.8%). These hybrid processes would not only be promising for the bioremediation of environmentally concerned contaminants but also reutilize waste materials as sorbents without any further treatment.
Show more [+] Less [-]Club convergence of per capita carbon emission: global insight from disaggregated level data Full text
2019
Haider, Salman | Akram, Vaseem
This study aims to examine the convergence hypothesis of per capita carbon dioxide emission and its component such as coal, oil, and gas in the case of 53 countries covering the period of 1980 to 2016. In particular, we study whether countries are moving toward a common steady-state equilibrium condition in the per capita carbon emission or converging into different groups. To do so, this study used Phillips and Sul (Econometrica 75(6): 1771–1855, 2007, J Appl Econ 24(7): 1153–1185, 2009) technique. Our results show no evidence of convergence for full sample. However, our results support the evidence of two club convergence of total emission, emission from gas and petroleum consumption, while three clubs are noticed in case of per capita carbon dioxide emission from coal use. This invalidates the equality rule of participation of each country in climate change policy. Further, similar results emerge in case of total emission and petroleum where club 1 consists of mostly developed countries while club 2 has a large number of developing countries. Interestingly, we do not find any divergence behavior across all countries in the sample. We find that natural gas is the major component to drive the total carbon emission convergence in case of our sample countries.
Show more [+] Less [-]The hematologic effects of BTEX exposure among elderly residents in Nanjing: a cross-sectional study Full text
2019
Chen, Qi | Sun, Hong | Zhang, Jiayao | Xu, Yan | Ding, Zhen
Few studies have examined the effects of environmental concentrations of benzene, toluene, ethylbenzene, and xylene (BTEX) on the hematologic system of residents near a petrochemical complex. This study evaluated the potential effects of blood BTEX concentrations on the hematologic parameters of residents in a community near a petrochemical complex (contaminated group) and another community free of known petrochemical pollution (control group). Volunteer residents were randomly recruited. Each participant completed a questionnaire and donated blood samples to evaluate blood BTEX concentrations and hematologic parameters. We found the mean concentrations of blood BTEX of the contaminated group were 1.2 to 6.7 times higher than the control group. Multiple hematologic parameters of participants were significantly different between the two study groups. Inverse associations were found for ln-transformed blood benzene concentrations with mean corpuscular hemoglobin concentration (MCHC) (β = − 2.75) and platelet counts (β = −8.18). Several weaker associations were also observed between other compounds and multiple hematologic parameters. Our results suggest that the residents living near petrochemical complexes have higher blood BTEX concentrations. Furthermore, the increased blood BTEX levels in residents are associated with the reduction in RBC counts, hemoglobin concentration, hematocrit, MCHC, and platelet counts. This study provided particularly important information for the health risk assessment of residents living near petrochemical complexes.
Show more [+] Less [-]The protective role of ascorbic acid in the hepatotoxicity of cadmium and mercury in rabbits Full text
2019
Mumtaz, Shumaila | Tareen, Shaukat | Khan, Rida | Andleeb, Saiqa | Ulhaq, Mazhar | Khan, Muhammad Adeeb | Shakir, Hafiz Abdullah
The liver is one of the vital and sensitive organs which are usually exposed against the toxicity of mercury (Hg) and cadmium (Cd). The main objective of the current study was to evaluate the potential toxicological effects of both Cd and Hg as individual and combined. Hepatotoxicity was evaluated by monitoring the biochemical parameters of the liver and their accumulation in the liver as well as therapeutic role of vitamin C in said toxicity in rabbits (Oryctolagus cuniculus). In this research, cadmium chloride (1.5 mg/kg), mercuric chloride (1.2 mg/kg), and vitamin C (150 mg/kg of body weight) were orally administered to treatment groups of the rabbits for 28 alternative days. Various biochemical parameters of the liver such as lactate dehydrogenase (LDH), aspartate aminotransferase (ASAT), bilirubin, alanine aminotransferase (ALAT), total protein, and gamma glutamyl transferase (GGT) were estimated using blood samples. Some biochemical parameters like ASAT, ALAT, LDH, GGT, and bilirubin were significantly elevated (P ≤ 0.001) in individual Cd and Hg treatment groups, while the level of total protein was found to be significantly declined. The effects of Cd and Hg in the presence of vitamin C on these biochemical parameters were low as compared to metals-treated groups. Similar results were found when rabbits were treated with co-administration of both metals and vitamin C. Accumulation of Cd and Hg found to be higher in the liver. However, chemoprevention and chemotreatment with vitamin C significantly (P ≤ 0.01) minimized the toxicological effects of both metals but not regained the accumulation similar to that of the control group. The findings of this study provide awareness on accumulation of metals in the liver in rabbits and their toxicity tested through biochemical parameters as well as the therapeutic role of vitamin C in such alterations.
Show more [+] Less [-]A cost compensation model for construction and demolition waste disposal in South China Full text
2019
Liu, Jingkuang | Teng, Yue | Jiang, Yuhan | Gong, Enqin
Construction and demolition waste (C&D waste) is a worldwide issue that concerns the sustainable development of the construction industry. In this paper, detailed formulas are listed for calculating the costs of four typical kinds of disposal routes of C&D waste. They are illegal dumping, controlled dumping (landfill), centralized recycling, and on-site recycling. Through the specific formulas, the costs of the new construction project in Guangzhou are also estimated. Then, a cost compensation model of construction waste disposal is constructed, which serves to calculate the amount of compensation that the government shall make to the contractor’s disposal cost. The results of this study include the following: (1) steps taken to ensure the appropriate measures for C&D waste disposal sites and recycling centers; (2) the on-site recycling will become the future trend of C&D waste disposal due to its lowest cost; (3) the brick cement mortar and scattered concrete take a relatively larger proportion in the total C&D waste generated during the new construction project, and their disposal costs are higher; (4) we find that the cost of illegal dumping is the lowest among four varieties of waste treatment options if only the direct cost of waste treatment is taken account. However, the cost of on-site recycling becomes the lowest if the total cost is considered; (5) according to the case study, the full estimated cost of construction waste disposal is 9074.56 CNY and the total cost compensation is 15,084.21 CNY. The amount of compensation is greater than the disposal cost and contractors make a profit, thus stimulating them to recycle and reuse construction waste. Based on the empirical findings, we make several policy proposals. The research puts forward some operational advice as a reference for decision-makers of C&D waste management.
Show more [+] Less [-]Diversity in flower colorations of Ranunculus asiaticus L. revealed by anthocyanin biosynthesis pathway in view of gene composition, gene expression patterns, and color phenotype Full text
2019
Liu, Yanfang | Zhang, Jianhua | Yang, Xiaohong | Wang, Jiangmin | Li, Yangang | Zhang, Peng | Mao, Jin | Huang, Qingmei | Tang, Hao
Anthocyanin biosynthesis is one of the best studied secondary metabolisms. However, related pathways were generally concluded based on anthocyanin components; most studies focused on the backbone forming of anthocyanidins (cyanidin, delphinidin, and pelargonidin) of model or commercial plants, while anthocyanin modification was less discussed, and non-model plants with abundant colorations were less researched either. Ranunculus asiaticus L. has great diversity in flower colorations, not only indicating its value in researching anthocyanin biosynthesis but also implying it is unique in this regard. Based on transcriptome sequencing and gene annotation of three varieties (10 samples) of Ranunculus asiaticus L., 176 unigenes from 151,136 unigenes were identified as involved in anthocyanin biosynthesis, among which, 74 unigenes were related to anthocyanin modification; 61 unigenes were responsible for glycosylation at C3 and C5 with 3-monosaccharides of glucose, 3-biosides of rutinose, sophorose, or sambubiose to form 3Gly-, 3Gly5Gly-, 3Gly3′Gly-, 3Gly2′′Gly-, 3Gly2′′Xly-, 3Gly2′′Rly-glycosylated anthocyanins, etc.; 2 unigenes transferred –CH₃; 11 unigenes of BAHD family catalyzd the aromatic or malonyl acylation at 6′′ / 6′′′′position of 3/5-O-glucoside. Based on gene composition, a putative pathway was established. The pathway was validated by flower colorations, and gene expression patterns where F3H, F3′H, 3GT, 5GT, and FMT2 were highly expressed in varieties colored as lateritious and carmine, while variety with purple flowers had high expression of F3′5′H and 3MAT. In view of anthocyanin biosynthesis pathway of Ranunculus asiaticus L., great diversity in its flower colorations was illustrated via the complete branches (F3H, F3′H and F3′5′H) as well as complete modifications (glycosylation, methylation, and acylation), and besides, via the higher percentage of C3 glycosylation than C5 glycosylation.
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