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The effects of high temperature on cardiovascular admissions in the most populous tropical city in Vietnam
2016
Phùng, Dũng | Guo, Yuming | Thái Phong, | Rutherford, Shannon | Wang, Xiaoming | Nguyen, Minh | Do, Cuong Manh | Nguyen, Nga Huy | Alam, Noore | Chu, Cordia
This study examined the short-term effects of temperature on cardiovascular hospital admissions (CHA) in the largest tropical city in Southern Vietnam. We applied Poisson time-series regression models with Distributed Lag Non-Linear Model (DLNM) to examine the temperature-CHA association while adjusting for seasonal and long-term trends, day of the week, holidays, and humidity. The threshold temperature and added effects of heat waves were also evaluated. The exposure-response curve of temperature-CHA reveals a J-shape relationship with a threshold temperature of 29.6 °C. The delayed effects temperature-CHA lasted for a week (0–5 days). The overall risk of CHA increased 12.9% (RR, 1.129; 95%CI, 0.972–1.311) during heatwave events, which were defined as temperature ≥ the 99th percentile for ≥2 consecutive days. The modification roles of gender and age were inconsistent and non-significant in this study. An additional prevention program that reduces the risk of cardiovascular disease in relation to high temperatures should be developed.
Показать больше [+] Меньше [-]Association of indoor air pollution from coal combustion with influenza-like illness in housewives
2016
Wang, Bin | Liu, Yingying | Li, Zhenjiang | Li, Zhiwen
An association of influenza-like illness (ILI) with outdoor air pollution has been reported. However, the effect of indoor air pollution on ILI was rarely investigated. We aimed to determine an association of indoor air pollution from coal combustion (IAPCC) and lifestyle with ILI risk in housewives, and the modification effect of phase II metabolic enzyme genes. We recruited 403 housewives for a cross-sectional study in Shanxi Province, China, including 135 with ILI frequency (≥1 time per year in the past ten years) as the case group and 268 with ILI frequency (<1 times per year) as the control group. Information on their energy usage characteristics and lifestyle was collected by questionnaires, as well as the single nucleotide polymorphisms (SNPs) of epoxide hydrolase 1 (rs1051740 and rs2234922), N-acetyltransferase 2 (rs1041983), and glutathione S-transferase (rs1695). We used exposure index to indicate the level of IAPCC among housewives. Our results revealed that the exposure index was positively correlated with ILI frequency. A significant dose-response trend between the exposure index and ILI risk was found with or without adjusting for confounders. Cooking frequency in kitchen with coal as primary fuel and ventilation frequency in the living room or bedroom with a coal-fueled stove for heating during the heating season were two important risk factors to affect ILI frequency. Only rs1051740 was found to be associated with exposure index, whereas it didn’t have interaction effect with exposure index on ILI frequency. In conclusion, IAPCC and SNPs of rs1051740 were both associated with ILI frequency.
Показать больше [+] Меньше [-]Benzo(a)pyrene in Europe: Ambient air concentrations, population exposure and health effects
2016
Guerreiro, C.B.B. | Horálek, J. | de Leeuw, F. | Couvidat, F.
This study estimated current benzo(a)pyrene (BaP) concentration levels, population exposure and potential health impacts of exposure to ambient air BaP in Europe. These estimates were done by combining the best available information from observations and chemical transport models through the use of spatial interpolation methods. Results show large exceedances of the European target value for BaP in 2012 over large areas, particularly in central-eastern Europe. Results also show large uncertainties in the concentration estimates in regions with a few or no measurement stations. The estimation of the population exposure to BaP concentrations and its health impacts was limited to 60% of the European population, covering only the modelled areas which met the data quality requirement for modelling of BaP concentrations set by the European directive 2004/107/EC. The population exposure estimate shows that 20% of the European population is exposed to BaP background ambient concentrations above the EU target value and only 7% live in areas with concentrations under the estimated acceptable risk level of 0.12 ng m−3. This exposure leads to an estimated 370 lung cancer incidences per year, for the 60% of the European population included in the estimation. Emissions of BaP have increased in the last decade with the increase in emissions from household combustion of biomass. At the same time, climate mitigation policies are promoting the use of biomass burning for domestic heating. The current study shows that there is a need for more BaP measurements in areas of low measurement density, particularly where high concentrations are expected, e.g. in Romania, Bulgaria, and other Balkan states. Furthermore, this study shows that the health risk posed by PAH exposure calls for better coordination between air quality and climate mitigation policies in Europe.
Показать больше [+] Меньше [-]Correlations and adsorption mechanisms of aromatic compounds on a high heat temperature treated bamboo biochar
2016
Yang, Kun | Yang, Jingjing | Jiang, Yuan | Wu, Wenhao | Lin, Daohui
Adsorption of aromatic compounds, including polycyclic aromatic hydrocarbons, nitrobenzenes, phenols, and anilines, on a bamboo biochar produced at 700 °C (Ba700) was investigated with the mechanism discussion by isotherm fitting using the Polanyi-theory based Dubinin–Ashtakhov (DA) model. Correlations of adsorption capacity (Q0) of organic compounds with their molecular sizes and melting points, as well as correlations of adsorption affinity (E) with their solvatochromic parameters (i.e., π* and αm), on the biochar, were developed and indicating that adsorption is captured by the pore filling mechanism and derived from the hydrophobic effects of organic compounds and the forming of π-π electron donor-acceptor (EDA) interactions and hydrogen bonding interactions of organic molecules with surface sites of the biochar. The effects of organic molecular sizes and melting points on adsorption capacity are ascribed to the molecular sieving effect and the packing efficiency of the organic molecules in the biochar pores, respectively. These correlations can be used to quantitatively estimate the adsorption of organic compounds on biochars from their commonly physicochemical properties including solvatochromic parameters, melting points and molecular cross-sectional area. The prediction using these correlations is important for assessing the unknown adsorption behaviors of new organic compounds and also helpful to guide the surface modification of biochars and make targeted selection in the environmental applications of biochars as adsorbents.
Показать больше [+] Меньше [-]Synoptic weather evolution and climate drivers associated with winter air pollution in New Zealand
2016
Fiddes, S.L. | Pezza, A.B. | Mitchell, T.A. | Kozyniak, K. | Mills, D.
Particulate matter pollution of less than 10 μm in diameter (PM10) is a problem for some regional and urban centres across New Zealand during the winter period when solid fuel (wood and coal) fires are used for home heating. Elevated levels of PM10 concentrations occur during stable atmospheric conditions, when cool air temperatures and low wind speeds allow for a surface inversion to occur and trap PM10. This study examined the relationships between PM10 and local and large-scale synoptic conditions at daily and seasonal scales. Minimum temperature and wind speed were both negatively correlated with PM10 during the winter season, whilst the combination of the two can explain 30–54% of variability in average PM10. Synoptic-scale daily composites of high PM10 days showed the evolution of an anticyclone in the Tasman Sea, with an injection of cool air over New Zealand and persistent south-westerly winds leading to cold and stable conditions on the day of exceedance. Both of these results indicate that there is some potential for predicting days in which atmospheric conditions could favour elevated PM10 concentrations. Furthermore, at the seasonal scale, weaker westerly winds were found to be associated with winters with higher exceedance days, although the relationship is not straightforward. These characteristics can be associated with other, predictable large-scale climate drivers such as the El Niño-Southern Oscillation, and may aid in identifying years in which a higher risk of PM10 pollution events exists.
Показать больше [+] Меньше [-]Evaluation of two composting strategies for making pig slurry solid fraction suitable for pelletizing
2016
Pampuro, Niccolò | Dinuccio, Elio | Balsari, Paolo | Cavallo, Eugenio
In this study, two composting strategies (not turned and turned windrows) of pig slurry solid fraction (SF) were evaluated and compared in terms of their suitability to obtain a composted manure appropriate for further pelletizing (i.e., moisture content <40%). The effect of the two composting strategies on carbon dioxide (CO2), methane (CH4), nitrous oxide (N2O) and ammonia (NH3) emissions were also investigated.Six identical SF windrows of approximately 4 m3 and 1800 kg were set up outside, on a concrete pad in an open-sided, roofed facility, and composted for a period of 72 days. During the experimental period, three SF windrows were composted unturned (NTW), while the others three SF windrows were turned (TW) six times: at day 7, 16, 28, 35, 50 and 57. Carbon dioxide, methane, nitrous oxide and ammonia emissions were measured three times a week for the first 3 weeks and twice per week thereafter for the 72 days of composting. In correspondence of each turning operation, gases emissions rates from TW, were evaluated two times: before and immediately after turning. Due to the production of heat generated during the composting process, high losses of water occurred from both NTW and TW. However, at the end of the trial the average moisture content in composted manure from NTW and from TW resulted, respectively, 46.7% and 34.6%. Therefore, under the specific conditions adopted in this study, composting of pig slurry SF in NTW did not give a suitable product for further pelletizing. In addition, composted manure from NTW resulted in significantly (p < 0.05) lower total nitrogen (2.9% vs 3.4%) and NO3–N (714 mg kg−1 vs 1358 mg kg−1) content. However, in terms of CO2-eq, total gaseous emissions recorded over 72 days of trial from TW (120.4 kg CO2-eq. t−1) were approximately 95% higher as compared to those (64.7 kg CO2-eq. t−1) obtained from NTW.
Показать больше [+] Меньше [-]Energetic and Entropic Features of Cu(II) Sorption Equilibria on Fibrous Clay Minerals
2016
Khosravi, Parisa | Shirvani, Mehran | Bakhtiary, Somayeh | Shariatmadari, Hossein
Sorption equilibria of copper(II) ions onto palygorskite and sepiolite clay minerals were studied as a function of temperature. The experimental data were fitted to the Langmuir, Freundlich, Temkin, and R-D models to obtain the isothermal constants. van’t Hoff, Gibbs, Clausius–Clapeyron, and modified Arrhenius equations were also employed to evaluate the thermodynamic parameters involved in Cu sorption. The results showed that fibrous clay minerals exhibit enhanced Cu(II) sorption capacities at higher temperatures. Enthalpy changes (ΔH°) were found to be positive, confirming that the process of Cu(II) sorption on both palygorskite and sepiolite was endothermic. Positive values were also obtained for the entropy changes (ΔS°), which suggests increased randomness at the solid-solution interface during the sorption of Cu(II) ions on both fibrous clay minerals investigated. The free energy changes (ΔG°) were negative for all the different temperatures and initial Cu(II) concentrations tested, indicating that sorption on the minerals is spontaneous and favorable. It was, therefore, concluded that sorption of Cu(II) ions on fibrous clay minerals is entropically driven. The values of isosteric heat of sorption (∆H ₓ) decreased with increasing sorption density, which shows that the clay surface is heterogeneous in terms of the active sites available for Cu(II) retention. The values of activation energy (E ₐ) and sticking probability (S *) generally lied within the ranges associated with physisorption for palygorskite and chemisorptions for sepiolite. In conclusion, the thermodynamic parameters investigated revealed the higher tendency and capacity of sepiolite, compared to palygorskite, for the feasible, spontaneous, and endothermic retention of Cu(II). However, the intensity of Cu(II) interactions with the fibrous clay minerals was found to depend to a large extent on the temperature and the initial Cu loading of the systems.
Показать больше [+] Меньше [-]Iron Anode-Mediated Activation of Persulfate
2016
Park, Sang-Min | Lee, Su-Won | Jeon, Pil-Yong | Baek, Kitae
Recently, persulfate (PS) has been applied to the oxidation of organic contaminants in wastewater, groundwater, and soil. However, PS requires activation by UV light, heat, transition metal, or pH control to be useful. In particular, transition metals are able to rapidly activate PS to sulfate radical. However, it is difficult to control the concentration of transition metal solution in an environmental setting. In this study, the potential of an electrochemical reaction using an iron anode to activate PS was investigated with phenol as a model contaminant. Based on Faraday’s law, Fe(II) generated by the electrochemical reaction was regularly supplied to the solution to activate PS to sulfate radical. The activation of PS was influenced by current intensity; however, excess Fe(II) decreased the oxidation rate of phenol because anodic oxidation-generated Fe(II) also scavenged sulfate radical. However, the electrochemical reaction using the iron anode could be readily controlled to supply an optimal amount of Fe(II) for activation of PS. Therefore, it is expected that this electrochemical process using an iron anode could be useful for the effective removal of phenol.
Показать больше [+] Меньше [-]Synthesis of Supported Ruthenium Catalyst for Phenol Degradation in the Presence of Peroxymonosulfate
2016
Anbia, Mansoor | Rezaie, Marzie
Industrial synthesis processes produce high concentration of hazardous organic pollutants into water body, which must be removed before being discharged. Advanced oxidation processes (AOPs) using heterogeneous catalysts has been widely utilized for wastewater treatment. Here, RuO₂-based catalyst was synthesized by a general impregnation method and used to oxidize phenol by peroxymonosulfate (PMS) as an oxidant in aqueous solution. The properties of this supported catalyst were characterized by SEM (scanning electron microscopy), XRD (powder X-ray diffraction), and nitrogen adsorption-desorption. The mesoporous Al₂O₃ support had large surface area and high thermal stability. It is found that ruthenium oxide-based catalyst is highly effective to activate PMS to related sulfate radicals. The effects of catalyst loading, phenol concentration, PMS concentration, reaction temperature, and reusability of the as-prepared catalyst on phenol degradation have been investigated. Overall, our findings demonstrate that in RuO₂/Al₂O₃ mesoporous catalyst, Oxone (PMS) is effectively activated, and 100% phenol degradation occurs in 60 min. To regenerate the deactivated catalyst and improve its catalytic properties, three different methods involving annealing in air, washing with water, and applying ultrasonics were used. The catalyst was recovered thoroughly by heating treatment.
Показать больше [+] Меньше [-]Genotoxic Effect and Carcinogenic Potential of a Mixture of As and Cd in Zebrafish at Permissible Maximum Contamination Levels for Drinking Water
2016
Doganlar, Oguzhan | Doganlar, Zeynep Banu | Muranlı, Fulya Dilek Gokalp | Guner, Utku
Currently, the toxic effects and carcinogenic potential of individually treated arsenic (As) or cadmium (Cd) are well documented both in animal and human tissues. However, there are no data focusing on the genotoxicity of these heavy metals as a mixture at the very low concentrations of permissible limits for drinking water. In this study, we examine the genotoxicity and carcinogenic potential of single and combined treatments of As and Cd, as well as attempt to elucidate the mechanism of action of certain cell defense systems such as antioxidants, gene repair, heat shock, cell cycle control, and the apoptosis pathway. Zebrafish (Danio rerio), reared under controlled conditions with artificial diets, were treated with As and Cd, either individually or in combination, at concentrations commonly found in water (10 ppb for As and 5 ppb for Cd) and tenfold higher concentrations for 48 h. Our results indicate that separately, As and Cd treatments at low dose selectively induce antioxidant enzymes, gene repair, and caspase-independent apoptosis in gill tissue, by targeting the mitochondria, leading to oxidative stress and sub-lethal levels of DNA damage. However, tenfold higher (100 ppb As + 50 ppb Cd) treatment caused significant downregulation of genes involved in double-strand break repair and molecular chaperone genes. Additionally, the highest BCL2/BAX ratio (1.6) and lowest expression levels of caspase-3 (8.4-fold) in all treated groups were observed in same condition. These results demonstrate that both single and combined exposure to As and Cd at permissible levels is potentially safe and causes repairable genotoxicity in gill tissue. However, the highest concentration is potentially carcinogenic due to ineffective DNA repair and insufficient apoptosis.
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