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A preliminary approach of the spatio-temporal distribution of cationic aerosol components in the ambient atmosphere of Kochi, India Full text
2016
Gayathree Devi, P.K. | Sujatha, C.H.
Kochi City, situated in the vicinity of the industrial hub and marine niche, is significantly loaded with ionic compounds and get into the atmospheric aerosols which deteriorate the health status of the environment. The distribution of both acid and water extractable cations (Na+, NH4+, K+, Mg2+ and Ca2+) with respect to time and space, in the two phases (I and II) were performed at distinct sites of Kochi, Kerala, India. The study revealed that the water soluble Na+ ion is highlighted in the estuarine site (E1) with momentous load at the coastal site (C1) implying the sea salt influence at these two sites. The average NH4+ and K+ concentration (acid and water soluble fractions) recorded is mostly at the industrial site (R2) which may be endorsed due to the application of NPK fertilizers and also from the process of wood burning sources. Further, K+ is the prominent acid and water soluble cation recorded in the study. Mg2+ ion having both oceanic and anthropogenic origin contributes the present observed pollution load. Average acid soluble Ca2+ content is noted maximum at the estuarine spot E1, where as the hike with respect to water soluble fraction of this ion is noticed at the industrial site, R2. These inferences justify the influence of point sources such as industrial, crustal and construction related activities affecting in and around this metropolis.
Show more [+] Less [-]Effect of abalone farming on seawater movement and benthic foraminiferal assemblage of Zostera marina in the inner bay of Wando, South Korea Full text
2016
Lee, Yeon Gyu | Choi, Yang Ho | Jeong, Da Un | Lee, Jung Sick | Kim, Yong-wan | Park, Jung Jun | Choi, Jae Ung
Tidal current survey as well as geochemical and benthic foraminiferal analyses of sediment cores were conducted in an abalone farm and a Zostera bed to understand the degree to which the abalone farm facilities installed along a channel in a shallow sea affect the benthic environment and ecology. In the abalone farm, Ammonia beccarii-Pseudoparrella naraensis-Elphidium somaense-Rosalina globularis-Trochammina hadai and P. naraensis-E. somaense-A. beccarii-T. hadai assemblages appeared owing to an increase in the total nitrogen content from the biodeposits. The Zostera bed consisted of A. beccarii-P. naraensis-Buccella frigida-T. hadai assemblage owing to the gradual expansion of a brackish shallow-water environment by the rapidly decreasing current speed, and it may have flourished. Moreover, the total sulfur, Zn, Cr, and Cu contents in the sediments decreased remarkably more than those of the pre-abalone farming did, caused by the vigorous activity of Zostera marina physiology.
Show more [+] Less [-]Sources and sinks of plastic debris in estuaries: A conceptual model integrating biological, physical and chemical distribution mechanisms Full text
2016
Vermeiren, Peter | Muñoz, Cynthia C. | Ikejima, Kou
Micro- and macroplastic accumulation threatens estuaries worldwide because of the often dense human populations, diverse plastic inputs and high potential for plastic degradation and storage in these ecosystems. Nonetheless, our understanding of plastic sources and sinks remains limited. We designed conceptual models of the local and estuary-wide transport of plastics. We identify processes affecting the position of plastics in the water column; processes related to the mixing of fresh and salt water; and processes resulting from the influences of wind, topography, and organism–plastic interactions. The models identify gaps in the spatial context of plastic–organisms interactions, the chemical behavior of plastics in estuaries, effects of wind on plastic suspension–deposition cycles, and the relative importance of processes affecting the position in the water column. When interpreted in the context of current understanding, sinks with high management potential can be identified. However, source–sink patterns vary among estuary types and with local scale processes.
Show more [+] Less [-]Development of an analytical method for determining hindered phenolic antioxidants in exhaust emissions from light-duty vehicles Full text
2016
Wang, Jingxian | Thomson, Meghan | Connolly, Trevor | Tong, Anthony Z.
Six hindered phenolic antioxidants (HPAs) from emissions of light-duty diesel and gasoline vehicles were determined. Vehicles were tested on a dynamometer that conducted a typical city-driving protocol and their exhaust samples were collected on filters. A high-performance liquid chromatography coupled with tandem mass spectrometry (HPLC-MS/MS) method was developed for the determination of HPAs in the exhaust samples. Method detection limits reached low ng/m3 in exhaust after optimization of experimental conditions. Identification and quantification were proven to be reliable for these phenols in lightly-loaded and ambient filter samples. In heavily loaded samples, matrix interferences existed, which decreased recoveries of surrogate in both filter and disk. However, matrix spike samples showed good recoveries of target HPAs. In vehicle emission samples, the highest level of HPAs was 2,6-di-tert-butylphenol at 52.7 ng/m3 (28.9 pg/mm2 on filter) in emission of a 2009 Volkswagen Jetta with a diesel engine. Most HPAs were not detected or near detection limits. Therefore, the additives of phenol antioxidants in fuels were mostly oxidized during the combustion process. Further, the 2009 diesel Jetta produced about 7 times more of HPAs than the 2008 Pontiac G5 with a gasoline engine. In addition, it is discovered that engines operated at a colder ambient temperature (−7 °C) yielded more HPA emissions than at the warmer condition (25 °C), because the combustion efficiency of engines are normally reduced at a lower temperature.
Show more [+] Less [-]Comparison of plume lateral dispersion coefficients schemes: Effect of averaging time Full text
2016
Hoinaski, Leonardo | Franco, Davide | de Melo Lisboa, Henrique
Dispersion modeling is an important decision tool for estimating the impact of human activities on the environment and its populations. However, it was proved by researchers that AERMOD and CALPUFF, the current regulatory models, do not account for the effect of averaging time. In consequence, these models do not have the ability to predict short-term time peak concentrations. This inability arises from the errors in the lateral and vertical dispersion estimates, which are reliable only to predict 10 min or longer average concentrations. In this paper, a novel evaluation based on Irwin (1983) was conducted to investigate the effect of averaging time on the lateral dispersion and maximum concentration estimates. The Pasquill-Gifford, Högström, Draxler (embedded in CALPUFF) and AERMOD lateral dispersion schemes were tested using the Round Hill II experiment, developed to investigate the effects of averaging time on atmospheric transport and diffusion. The observed lateral dispersion was derived from the lateral concentration profiles along 3 sampling arcs (50, 100 and 200 m), measured on 3 different averaging times (0.5; 3 and 10 min). The observed lateral dispersion was compared to those estimates. The results of the comparison show that AERMOD and Draxler correlate better with measured data than the PG and Högström methods. However, their estimates are biased and the magnitude of systematic errors tends to grow as the averaging time decreases. Moreover, AERMOD and Draxler, with Peak-to-Mean (P-M) adjustment, tend to overestimate the lateral dispersion farther from the source and underestimate at downwind distances less than 200 m. The analysis also highlights some concerns on the P-M ratio application due its subjectivity. The present investigation on the effect of short-term averaging times on atmospheric transport and diffusion may help to understand some issues related to the use of dispersion models in the case of flammability, malodor nuisance and toxicity
Show more [+] Less [-]Study on the association between air pollution and mortality in İstanbul, 2007–2012 Full text
2016
Çapraz, Özkan | Efe, Bahtiyar | Deniz, Ali
We examined the associations between the daily variations of air pollutants and mortality in the population of İstanbul, Turkey, using generalized linear models while controlling for time trends and meteorological factors over a 6-year period (2007–2012) at different time lags (0–10 days). Effects of the pollutants (Relative Risk (RR) on current-day (lag 0) mortality to the first ten days (lag 10) were determined. Data on daily mortality, daily mean concentrations of air pollutants of PM10, SO2 and NO2 and daily mean concentrations of temperature and humidity for İstanbul were used in the study. We found significant associations between air pollution and daily mortality from cardiovascular disease, respiratory diseases, and total non-accidental causes in İstanbul. An increase of 10 μg/m3 in concentrations of PM10, SO2 and NO2 over 10 days of lag corresponds to RR = 1.0222 (95% Confidence Interval (CI) = 0.9957–1.0494), RR = 1.1639 (95% CI = 1.0279–1.3177) and RR = 1.0327 (95% CI = 1.0105–1.0554) increase of cardiovascular mortality, respectively. The associations for total non-accidental and respiratory mortality were also positive. Among the three air pollutants, SO2 was associated with the largest RR for deaths from cardiovascular disease, respiratory disease and total mortality. In conclusion, our study showed that short-term exposure to air pollution was associated with increased cardiovascular, respiratory and total non-accidental mortality in the city during 2007–2012. These findings may have implications for local environmental and social policies.
Show more [+] Less [-]Priority pesticides in sediments of European coastal lagoons: A review Full text
2016
Pinto, M.I. | Burrows, Hugh | Sontag, G. | Vale, C. | Noronha, J.P.
This review summarizes the legislation applied to pesticides and highlights the physicochemical properties of the past and recently listed PPs under Water Framework Directive (WFD). It reports important information regarding the analysis, occurrence and long-term screening of PPs in sediments of European coastal lagoons. Among the entire list of PPs, those analyzed have been the organochloride insecticides, such as lindane, hexachlorobenzene and DDT. Although flood events pointed to the possible redistribution of pesticides, which may increase under climate change conditions, few studies are available concerning PPs screening in sediments of European coastal lagoons. Data is scarce not only in terms of the number of listed PPs that have been analyzed but also in terms of their long-term screening. This lack of data on PP concentrations is probably a consequence of the fact that less importance is given to the sediments contamination/quality.
Show more [+] Less [-]Bioaccumulation and retention kinetics of cesium in the Milkfish Chanos chanos from Jakarta Bay Full text
2016
Prihatiningsih, Wahyu Retno | Suseno, Heny | Zamani, Neviaty P. | Soedharma, Dedy
Laboratory radiotracer experiments were conducted to study the uptake, assimilation, and retention of cesium (137Cs) in milkfish (Chanos chanos) from Jakarta Bay. In this study, we have examined the bioaccumulation and distribution of 137Cs in C. chanos obtained from 137Cs-labeled seawater and 137Cs-labeled Artemia sp. feeding. The uptake of 137Cs via seawater displayed a one-compartment model suggesting that the concentration factors of 137Cs within the milkfish (weight 2.46–9.86g) at a steady-state period were between 10.66 and 3.98mLg−1 after 10days of exposure. The depuration rate was observed to be low, with only 22.80–49.14% of 137Cs absorbed by C. chanos, which was absent 6days after exposure. By contrast, depuration occurred quickly for radiolabeled food uptake, reaching 20% of retention within 10days after exposure. Muscles and viscera of the milkfish exhibited the highest degree of end uptake and end depuration of 137Cs from seawater and feeding.
Show more [+] Less [-]Polycyclic aromatic hydrocarbons (PAHs) in water from three estuaries of China: Distribution, seasonal variations and ecological risk assessment Full text
2016
Yan, Jinxia | Liu, Jingling | Shi, Xuan | You, Xiaoguang | Cao, Zhiguo
The distribution, seasonal variations and ecological risk assessment of polycyclic aromatic hydrocarbons (PAHs) in water from three estuaries in Hai River Basin of China, which has been suffering from different anthropogenic pressures, were investigated. In three estuaries, the average concentration of ΣPAHs was the lowest in Luan River estuary, followed by Hai River estuary, and the highest in Zhangweixin River estuary. There were significant seasonal variations in ΣPAHs, the concentrations of ΣPAHs were higher in November than in May and August. The composition profiles of PAHs in different sites were significantly different, and illustrated seasonal variations. Generally, 2-ring (Nap) and 3-ring PAHs (Acp, Fl and Phe) were the most abundant components at most sampling sites in three estuaries. The PAHs in three estuaries were mainly originated from pyrogenic sources. A method based on toxic equivalency factors (TEFs) and risk quotient (RQ) was proposed to assess the ecological risk of ΣPAHs, with the ecological risk of individual PAHs being considered separately. The results showed that the ecological risks caused by ΣPAHs were high in Hai River estuary and Zhangweixin River estuary, and moderate in Luan River estuary. The mean values of ecological risk in August were lower than those in November. The contributions of individual PAHs to ecological risk were different in May, August and November. 3-ring and 4-ring PAHs accounted for much more ecological risk than 2-ring, 5-ring and 6-ring, although the contributions of 5-ring and 6-ring to ecological risk were higher than these to PAHs concentrations.
Show more [+] Less [-]The implications of recurrent disturbances within the world's hottest coral reef Full text
2016
Bento, Rita | Hoey, Andrew S. | Bauman, Andrew G. | Feary, David A. | Burt, John A.
Determining how coral ecosystems are structured within extreme environments may provide insights into how coral reefs are impacted by future climate change. Benthic community structure was examined within the Persian Gulf, and adjacent Musandam and northern Oman regions across a 3-year period (2008–2011) in which all regions were exposed to major disturbances. Although there was evidence of temporal switching in coral composition within regions, communities predominantly reflected local environmental conditions and the disturbance history of each region. Gulf reefs showed little change in coral composition, being dominated by stress-tolerant Faviidae and Poritidae across the 3years. In comparison, Musandam and Oman coral communities were comprised of stress-sensitive Acroporidae and Pocilloporidae; Oman communities showed substantial declines in such taxa and increased cover of stress-tolerant communities. Our results suggest that coral communities may persist within an increasingly disturbed future environment, albeit in a much more structurally simple configuration.
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