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Particulate matter modifies the magnitude and time course of the non-linear temperature-mortality association
2015
Li, Li | Yang, Jun | Guo, Cui | Chen, Ping-Yan | Ou, Chun-Quan | Guo, Yuming
It remains uncertain whether air pollution modifies the magnitude and time course of the temperature-mortality association. We applied a distributed lag non-linear model (DLNM) combined with non-linear interaction terms to assess the modifying effects of particulate matter with an aerodynamic diameter of 10 μm or less (PM10) on the association between mean temperature and mortality in Guangzhou, China. We found that both cold and hot effects increased with the quartiles of PM10. The elderly were more vulnerable to cold and hot effects. Men suffered more from cold-related mortality than women, with the gender difference enlarging with the quartiles of PM10. We identified statistically significant interaction effects between PM10 and mean temperature on mortality (except for respiratory mortality). Cold and hot effects basically appeared acutely on highly polluted days, while effects were delayed on lowly polluted days. The findings indicate the importance of reducing PM10 emission on extremely temperature days.
Afficher plus [+] Moins [-]Sedimentology and geochemistry of mud volcanoes in the Anaximander Mountain Region from the Eastern Mediterranean Sea
2015
Talas, Ezgi | Duman, Muhammet | Küçüksezgin, Filiz | Brennan, Michael L. | Raineault, Nicole A.
Investigations carried out on surface sediments collected from the Anaximander mud volcanoes in the Eastern Mediterranean Sea to determine sedimentary and geochemical properties. The sediment grain size distribution and geochemical contents were determined by grain size analysis, organic carbon, carbonate contents and element analysis. The results of element contents were compared to background levels of Earth’s crust. The factors that affect element distribution in sediments were calculated by the nine push core samples taken from the surface of mud volcanoes by the E/V Nautilus. The grain size of the samples varies from sand to sandy silt. Enrichment and Contamination factor analysis showed that these analyses can also be used to evaluate of deep sea environmental and source parameters. It is concluded that the biological and cold seep effects are the main drivers of surface sediment characteristics from the Anaximander mud volcanoes.
Afficher plus [+] Moins [-]Distributions and sources of volatile chlorocarbons and bromocarbons in the Yellow Sea and East China Sea
2015
Yang, Bin | Yang, Gui-Peng | Lu, Xiao-Lan | Li, Li | He, Zhen
Six volatile halogenated organic compounds (VHOC), namely, chloroform, carbon tetrachloride, trichloroethylene, bromodichloromethane, dibromochloromethane, and bromoform, were studied in the Yellow Sea and East China Sea from April to May, 2009. The spatial variability of these VHOC was influenced by various factors, including anthropogenic inputs, biogenic production and complicated hydrographic features such as Changjiang Diluted Water, Yellow Sea Cold Water Mass, and Kuroshio Current. Diurnal study results showed that factors such as solar irradiation, biological activity, and tide affected the abundance of these VHOC. Correlation analyses revealed that bromodichloromethane was positively correlated with chlorophyll a in surface seawater. Principal component analysis suggested that chlorinated compounds like carbon tetrachloride originated from anthropogenic sources whereas brominated compounds such as bromodichloromethane originated from biogenic sources. Sources of other chlorinated and brominated compounds may not be governed by biological processes in the marine environment.
Afficher plus [+] Moins [-]Evaluating the potential of ecological niche modelling as a component in marine non-indigenous species risk assessments
2015
Leidenberger, Sonja | Obst, Matthias | Kulawik, Robert | Stelzer, Kerstin | Heyer, Karin | Hardisty, Alex | Bourlat, Sarah J.
Marine biological invasions have increased with the development of global trading, causing the homogenization of communities and the decline of biodiversity. A main vector is ballast water exchange from shipping. This study evaluates the use of ecological niche modelling (ENM) to predict the spread of 18 non-indigenous species (NIS) along shipping routes and their potential habitat suitability (hot/cold spots) in the Baltic Sea and Northeast Atlantic. Results show that, contrary to current risk assessment methods, temperature and sea ice concentration determine habitat suitability for 61% of species, rather than salinity (11%). We show high habitat suitability for NIS in the Skagerrak and Kattegat, a transitional area for NIS entering or leaving the Baltic Sea. As many cases of NIS introduction in the marine environment are associated with shipping pathways, we explore how ENM can be used to provide valuable information on the potential spread of NIS for ballast water risk assessment.
Afficher plus [+] Moins [-]Temporal variations of PM1 major components in an urban street canyon
2015
Yubero, E. | Galindo, N. | Nicolás, J. F. | Crespo, J. | Calzolai, G. | Lucarelli, F.
Seasonal changes in the levels of PM₁ and its main components (organic carbon (OC), elemental carbon (EC), SO₄ ²⁻, NO₃ ⁻ and NH₄ ⁺) were studied in an urban street canyon in southeastern Spain. Although PM₁ levels did not show an evident seasonal cycle, strong variations in the concentrations of its major components were observed. Ammonium sulfate, the main secondary inorganic compound, was found to be of regional origin. Its formation was favored during summer due to increased photochemical activity. In contrast, the concentrations of particulate ammonium nitrate, which is thermally unstable, were highest in winter. Although traffic emissions are the dominant source of EC in the city, variations in traffic intensity could not explain the seasonal cycle of this component. The higher EC concentrations during the cold months were attributed to the lower dispersion conditions and the increase in EC emissions. Special attention has been given to variations in organic carbon levels since it accounted for about one third of the total PM₁ mass. The concentrations of both total OC and secondary OC (SOC) were maxima in winter. The observed seasonal variation in SOC levels is similar to that found in other southern European cities where the frequency of sunny days in winter is high enough to promote photochemical processes.
Afficher plus [+] Moins [-]Elements and polycyclic aromatic hydrocarbons in exhaust particles emitted by light-duty vehicles
2015
Alves, Célia A. | Barbosa, Cátia | Rocha, Sonia | Calvo, Ana | Nunes, Teresa | Cerqueira, Mário | Pio, Casimiro | Karanasiou, Angeliki | Querol, X. (Xavier)
The main purpose of this work was to evaluate the chemical composition of particulate matter (PM) emitted by eight different light-duty vehicles. Exhaust samples from petrol and diesel cars (Euro 3 to Euro 5) were collected in a chassis dynamometer facility. To simulate the real-world driving conditions, three ARTEMIS cycles were followed: road, to simulate a fluid traffic flow and urban with hot and cold starts, to simulate driving conditions in cities. Samples were analysed for the water-soluble ions, for the elemental composition and for polycyclic aromatic hydrocarbons (PAHs), respectively, by ion chromatography, inductively coupled plasma atomic emission spectroscopy (ICP-AES), inductively coupled plasma mass spectrometry (ICP-MS) and gas chromatography-mass spectrometry (GC-MS). Nitrate and phosphate were the major water-soluble ions in the exhaust particles emitted from diesel and petrol vehicles, respectively. The amount of material emitted is affected by the vehicle age. For vehicles ≥Euro 4, most elements were below the detection limits. Sodium, with emission factors in the ranges 23.5–62.4 and 78.2–227μg km⁻¹, for petrol and diesel Euro 3 vehicles, respectively, was the major element. The emission factors of metallic elements indicated that diesel vehicles release three to five times more than petrol automobiles. Element emissions under urban cycles are higher than those found for on-road driving, being three or four times higher, for petrol vehicles, and two or three times, for diesel vehicles. The difference between cycles is mainly due to the high emissions for the urban cycle with hot start-up. As registered for elements, most of the PAH emissions for vehicles ≥Euro 4 were also below the detection limits. Regardless of the vehicle models or driving cycles, the two- to four-ring PAHs were always dominant. Naphthalene, with emission factors up to 925 μg km⁻¹, was always the most abundant PAH. The relative cancer risk associated with naphthalene was estimated to be up to several orders of magnitude higher than any of the chemical species found in the PM phase. The highest PAH emission factors were registered for diesel-powered vehicles. The condition of the vehicle can exert a decisive influence on both element and PAH emissions.
Afficher plus [+] Moins [-]A margin of exposure approach to assessment of non-cancerous risk of diethyl phthalate based on human exposure from bottled water consumption
2015
Zare Jeddi, Maryam | Rastkari, Noushin | Ahmadkhaniha, Reza | Yunesian, Masud | Nabizadeh, Ramin | Daryabeygi, Reza
Phthalates may be present in food due to their widespread presence as environmental contaminants or due to migration from food contact materials. Exposure to phthalates is considered to be potentially harmful to human health as well. Therefore, determining the main source of exposure is an important issue. So, the purpose of this study was (1) to measure the release of diethyl phthalate (DEP) in bottled water consumed in common storage conditions specially low temperature and freezing conditions; (2) to evaluate the intake of DEP from polyethylene terephthalate (PET) bottled water and health risk assessment; and (3) to assess the contribution of the bottled water to the DEP intake against the tolerable daily intake (TDI) values. DEP migration was investigated in six brands of PET-bottled water under different storage conditions room temperature, refrigerator temperature, freezing conditions (40 °C ,0 °C and −18 °C) and outdoor] at various time intervals by magnetic solid extraction (MSPE) using gas chromatography–mass spectroscopy (GC-MS). Eventually, a health risk assessment was conducted and the margin of exposure (MOE) was calculated. The results indicate that contact time with packaging and storage temperatures caused DEP to be released into water from PET bottles. But, when comprising the DEP concentration with initial level, the results demonstrated that the release of phthalates were not substantial in all storage conditions especially at low temperatures (<25 °C) and freezing conditions. The daily intake of DEP from bottled water was much lower than the reference value. However, the lowest MOE was estimated for high water consumers (preschooler > children > lactating women > teenagers > adults > pregnant women), but in all target groups, the MOE was much higher than 1000, thus, low risk is implied. Consequently, PET-bottled water is not a major source of human exposure to DEP and from this perspective is safe for consumption.
Afficher plus [+] Moins [-]Evaluation of a permeable reactive barrier to capture and degrade hydrocarbon contaminants
2015
Mumford, K. A. | Powell, S. M. | Rayner, J. L. | Hince, G. | Snape, I. | Stevens, G. W.
A permeable reactive barrier (PRB) was installed during 2005/2006 to intercept, capture and degrade a fuel spill at the Main Power House, Casey Station, Antarctica. Here, evaluation of the performance of the PRB is conducted via interpretation of total petroleum hydrocarbon (TPH) concentrations, degradation indices and most probable number (MPN) counts of total heterotroph and fuel degrading microbial populations. Results indicate that locations which contained the lowest TPH concentrations also exhibited the highest levels of degradation and numbers of fuel degrading microbes, based on the degradation indices and MPN methods selected. This provides insights to the most appropriate reactive materials for use in PRB’s in cold and nutrient-limited environments.
Afficher plus [+] Moins [-]One-year intensive characterization on PM2.5 nearby port area of Thessaloniki, Greece
2015
Tolis, Evangelos I. | Saraga, Dikaia E. | Filiou, Katerina F. | Tziavos, Nikolaos I. | Tsiaousis, Chistos P. | Dinas, Athanasios | Bartzis, John G.
The chemical characterization of particulate matter (PM) 2.5 fraction was studied during a 1-year sampling campaign conducted at a site near Thessaloniki’s port area. PM2.5 collected samples were chemically analyzed for polycyclic aromatic hydrocarbons, minerals, and trace elements (Pb, Ni, Cu, V, Mn, Cr, Zn, Mg, K, Ti, Fe, Ca, and Al); water-soluble ions (Cl⁻, NO₃⁻, SO₄²⁻, K⁺, Na⁺, NH₄⁺, Mg²⁺, Ca²⁺); and organic and elemental carbon. The average annual PM2.5 concentration (66.0 μg/m³) was at the highest level compared with other studies reported for the same city but different sampling sites. The average daily sum of the measured concentration of polycyclic aromatic hydrocarbons (PAHs) was 12.76 ng/m³; this value decreased to 6.73 ng/m³for the warm period and reached the value of 19.8 ng/m³for the cold period. The average concentration of benzo[a]pyrene during the sampling period was 0.75 ng/m³, which is below the European Union limit value of 1.0 ng/m³. The ionic content comprised, on average, 22.6 % of the PM2.5 mass, with sulfate and ammonium being the most abundant species (31 and 26 %, respectively, of measured ions during the whole sampling period). The annual mean concentrations of organic carbon (OC) and elemental carbon (EC) were 10.5 ± 6.3 and 2.3 ± 1.5 μg/m³, respectively. The OC/EC ratio ranged from 1.6 to 9.9, suggesting that there is a significant influence of residential wood burning for heating as well as ship and vehicle emissions to the sampling area. Finally, the elemental composition of associated PM2.5 was dominated by Ca, Fe, and Al. Although conclusions based only on PM2.5 measurements cannot entirely estimate all harbor sources’ contribution, there is evidence to support that port activities affect the city’s air quality and vice versa.
Afficher plus [+] Moins [-]Size distribution of total and water-soluble fractions of particle-bound elements—assessment of possible risks via inhalation
2015
Voutsa, D. | Anthemidis, A. | Giakisikli, G. | Mitani, K. | Besis, A. | Tsolakidou, A. | Samara, C.
The size distribution of total and water-soluble elemental concentrations in six particle sizes <0.49, 0.49–0.97, 0.97–1.5, 1.5–3.0, 3.0–7.2, and 7.2–30 μm was investigated in Thessaloniki area, N. Greece, at two sites representing urban-traffic and urban-background character during the cold and warm period. The elements As, Cd, Cr, Cu, Pb, Ni, Zn, Ru, and Ir exhibited their highest mass portion in the fine particle mode (0.97–1.5 μm), whereas Al, Ba, Ca, Fe, and Mn occurred predominately in the coarse particle mode (3.0–7.2 μm). The water-soluble elemental fractions exhibited significant spatiotemporal variations and particle size dependence. Possible non-carcinogenic and carcinogenic risks associated with inhalation of particle-bound elements based on total and water-soluble concentrations were in acceptable levels. However, the cumulative risk for all potential particle-bound constituents has to be considered.
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