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Spatial representativeness of air quality monitoring stations: A grid model based approach Full text
2015
Piersanti, Antonio | Vitali, Lina | Righini, Gaia | Cremona, Giuseppe | Ciancarella, L. (Luisella)
A methodology for quantifying areas of spatial representativeness of air quality monitoring station is here proposed, exploiting the wide spatial and temporal coverage of chemical transport models results. The method is based on the analysis of time series of model concentrations, extracted at monitoring sites and around, by means of a Concentration Similarity Function (CSF). The method was tested on AMS-MINNI model results, covering Italy and three reference years (2003, 2005, 2007), for assessing the spatial representativeness of PM2.5 and O3 rural background monitoring stations. The CSF methodology shows good performances in describing both the extension and the shape of representativeness areas, taking into account the difference between pollutants and the dependence on averaging time and temporal interval of concentration data. Results show a large variability in the size and shape of the selected stations in Italy, ranging from 220 to 4500 km2. This confirms the importance of carrying out ad-hoc analyses on monitoring stations, as general a priori classifications and qualitative assessments of spatial representativeness are not able to fully capture the complexity of different territorial contexts.
Show more [+] Less [-]Development and laboratory evaluation of a compact swirling aerosol sampler (SAS) for collection of atmospheric bioaerosols Full text
2015
Wubulihairen, Maimaitireyimu | Lü, Xiaoying | Lee, Patrick K.H. | Ning, Zhi
Inhalation of infectious bioaerosols has been linked to a variety of respiratory diseases. However, efficient sampling techniques to allow high temporal resolution sampling are limited to collect and study bioaerosols in the various occupational and ambient micro–environmental atmospheres. This study introduces a medium flow swirling bioaerosol sampler (SAS) approach that collects atmospheric bioaerosols at the flow rate of 167 Lpm (10 cubic meter per hour). The collection of bioaerosols is achieved through a combination of impaction and cyclonic centrifugal motion. Aerosol deposition efficiency tests were performed with monodispersive polystyrene latex (PSL) particles ranging from 0.1 to 10 μm. Results have shown that the sampler has cut–off size of 0.7 μm and 1.5 μm, with and without the assistance of added water vapor, respectively. The bioaerosol collection and viability tests were performed with comparison to the commercially–available BioSampler, and the results show that the collection efficiency of the SAS is 97% at the designed flow rate, while the higher flow of the new system yields more than 13 times of the collection rate compared to the BioSampler. The high collection efficiency and observed viability preservation of the SAS make it an attractive alternative for high time resolution bioaerosol sampling for atmospheric, occupational and indoor air quality monitoring.
Show more [+] Less [-]Legal and institutional tools to mitigate plastic pollution affecting marine species: Argentina as a case study Full text
2015
González Carman, Victoria | Machain, Natalia | Campagna, Claudio
Plastics are the most common form of debris found along the Argentine coastline. The Río de la Plata estuarine area is a relevant case study to describe a situation where ample policy exists against a backdrop of plastics disposed by populated coastal areas, industries, and vessels; with resultant high impacts of plastic pollution on marine turtles and mammals. Policy and institutions are in place but the impact remains due to ineffective waste management, limited public education and awareness, and weaknesses in enforcement of regulations. This context is frequently repeated all over the world. We list possible interventions to increase the effectiveness of policy that require integrating efforts among governments, the private sector, non-governmental organizations and the inhabitants of coastal cities to reduce the amount of plastics reaching the Río de la Plata and protect threatened marine species. What has been identified for Argentina applies to the region and globally.
Show more [+] Less [-]Metal and metalloid concentrations in the tissues of dusky Carcharhinus obscurus, sandbar C. plumbeus and white Carcharodon carcharias sharks from south-eastern Australian waters, and the implications for human consumption Full text
2015
Gilbert, Jann M. | Reichelt-Brushett, Amanda J. | Butcher, Paul A. | McGrath, Shane P. | Peddemors, Victor M. | Bowling, Alison C. | Christidis, Les
Shark fisheries have expanded due to increased demand for shark products. As long-lived apex predators, sharks are susceptible to bioaccumulation of metals and metalloids, and biomagnification of some such as Hg, primarily through diet. This may have negative health implications for human consumers. Concentrations of Hg, As, Cd, Cu, Fe, Se and Zn were analysed in muscle, liver and fin fibres (ceratotrichia) from dusky Carcharhinus obscurus, sandbar Carcharhinus plumbeus, and white Carcharodon carcharias sharks from south-eastern Australian waters. Concentrations of analytes were generally higher in liver than in muscle and lowest in fin fibres. Muscle tissue concentrations of Hg were significantly correlated with total length, and >50% of sampled individuals had concentrations above Food Standards Australia New Zealand’s maximum limit (1mgkg−1ww). Arsenic concentrations were also of concern, particularly in fins. Results warrant further investigation to accurately assess health risks for regular consumption of shark products.
Show more [+] Less [-]Coastal waters environmental monitoring supported by river basin pluviometry and offshore wave data Full text
2015
Abramic, Andrej | Martínez-Alzamora, Nieves | González del Rio Rams, Julio | Ferrer Polo, José
Environmental monitoring in the scope of the Water Framework Directive 2000/60/EC (WFD) is usually expensive and requires considerable human effort. In this study, we analyzed data obtained by a WFD coastal waters monitoring network over a three-year period (35 campaigns), with the aim to ascertain is it possible to increase the monitoring efficiency and obtain more accurate results. As the trophic condition of the coastal waters of Valencia is primarily, but not entirely, determined by continental loads and hydrodynamic conditions, additionally we analyzed related river basin pluviometry (daily frequency) and oceanographic (one hour frequency) data. Chlorophyll a, salinity, rain and wave data time series were analyzed separately, to identify any possible pattern. Analyzing coastal water bodies integrating all four parameters, it is found strong interactions between coastal waters trophic conditions, sea hydrodynamics and related basin pluviometry. Eight phytoplankton biomass scenarios associated to environmental conditions are identified and finally developed basis for a new efficient monitoring strategy and more accurate coastal waters assessment.
Show more [+] Less [-]Evaluation of steelmaking slag as basal media for coastal primary producers Full text
2015
Akiyama, Yoshihiro B. | Yano, Hitomi | Koba, Kyohei | Katayama, Takahiro | Asaoka, Satoshi | Okuda, Tetsuji | Nakai, Satoshi | Yamamoto, Tamiji | Nishijima, Wataru
The use of granular steelmaking slag as a substitute for natural sand in the construction of tidal flats was investigated. Using an intertidal flat simulator, we evaluated dephosphorization slag mixed with 8% by dry weight of dredged sediment (DPS+DS) as a basal medium for the growth of benthic macro- and microalgae in comparison with silica sand mixed with 8% dredged sediment (SS+DS). Species compositions of macro- and microalgae were distinctly different between DPS+DS and SS+DS. The mean dry weight of macroalgae on DPS+DS was three orders of magnitude higher than that on SS+DS. Sediment shear strength and pH were higher in DPS+DS than in SS+DS or in the sediment of natural tidal flats. These results suggest that DPS contributes to changing the sediment environment, thereby changing the algal composition compared to the composition on natural tidal flats.
Show more [+] Less [-]Mapping the Global Dust Storm Records: Review of Dust Data Sources in Supporting Modeling/Climate Study Full text
2015
Wang, Julian X. L.
Dust storms, as extreme environmental events, are one of the Earth’s major natural hazards. Their impact on socio-economics can range from local urban to (trans-) continental and from minutes to decades, such as the dust bowl of the 1930s in the United States. Research on dust storms can be traced back for several decades as a meteorological extension. Latest technology developments have enabled comprehensive studies on dust storms, including sampling improvement, analytic studies, and numerical modeling. However, inhomogeneity of the data has hampered and sometimes even misguided research on comprehensive understanding of dust storms and exploring their feedbacks with climate. This review will focus on currently available observations of dust activities, which include routine meteorological records, in situ air chemistry observations, and satellite remote sensing. The aim is to show data sources and the status of their usage in a common framework for global dust regions. Emphasis is placed on data continuity and the spatial and temporal coverage of dust storms, since it is anticipated that this brief summary of dust data will benefit modeling and climate studies. Therefore, it must be noted that field campaign data are outside of the scope of the current review, although they play an important role in research and understanding.
Show more [+] Less [-]Remediation of DDT and Its Metabolites in Contaminated Sediment Full text
2015
Chattopadhyay, Sandip | Chattopadhyay, Devamita
Chlorinated pesticides and chlorinated organics can be transformed or partially degraded in sediments under appropriate environmental conditions. Although 1,1,1-trichloro-2,2-bis[p-chlorophenyl]ethane (DDT) is very persistent in the environment, 1,1-dichloro-2,2-bis(p-chlorophenyl)ethylene (DDE), a degradation product of DDT, is generally the constituent most widely detected in the environment and DDE is also resistant to further biotransformation. DDT and its degradation products (DDTR) may be transported from one medium to another by sorption, bioaccumulation, dissolution, or volatilization. In sediments, DDT strongly adheres to suspended particles, but once metabolized, DDE, the primary product, is slightly soluble in water. The major migration process for DDTR in sediment-water systems is sorption to sediment or other organic matter and the primary distribution route is the transportation of the particulates to which the compound is bound. Understanding the fate and transport of DDTR in the natural environment based on its specific characteristics is important in determining appropriate remediation option. Common DDT-contaminated sediment remediation options include dredging, capping, and natural attenuation. Sediment washing and phytoremediation have also been used in contaminated sites. Dredging is the most common sediment remediation option to remove the contaminated benthic sediments but often suffers from technical limitations like incomplete removal, unfavorable site conditions, sediment resuspension, and disposal issues. Capping is an in situ, low-cost remediation option for immobilization of DDT in several contaminated sediment sites. Natural or anthropogenic materials containing reactive ingredients, as distinct from a conventional sand or gravel cap, involve placing reactive materials as part of the cap matrix to increase sorption, and to enhance chemical reactivity with DDTR, or accelerate degradation. Natural attenuation can treat the DDT-contaminated sediment, but the time frame for complete remediation may be relatively long. Addition of suitable co-metabolites and acclimatized microorganisms to DDTR-contaminated sediment and alteration of sediment-water micro-environment by manipulating soil pH, moisture content, and other chemical conditions may result in degradation of DDTR associated with sediments at rates faster than the natural attenuation rate.
Show more [+] Less [-]Applying sediment quality guidelines on soft sediments of the Gulf of Finland, Baltic Sea Full text
2015
Vallius, Henry
The Gulf of Finland is known to have been rather largely contaminated by heavy metals during the last half of the 20th century, but indications of recovery have been reported. In order to investigate the recent levels of heavy metals and arsenic in the uppermost soft sediments of the off-shore Gulf of Finland coring of altogether 23 sites were performed. The subsamples of the cores are 605 in total and thus give a good picture of heavy metal levels in the surface sediments during the first decade of this century. In order to evaluate methods and predict sediment toxicity the sediment concentrations are compared to American SQG:s. Majority of the subsamples exceeded the threshold levels of both used SQG:s, but some exceeded also the midrange effects quality guidelines. As, Cd, Hg, and Zn concentrations still occur at unacceptably high levels in sediments of the off-shore Gulf of Finland.
Show more [+] Less [-]Assessment of swimming associated health effects in marine bathing beach: An example from Morib beach (Malaysia) Full text
2015
Praveena, Sarva Mangala | Pauzi, Norfasmawati Mohd | Hamdan, Munashamimi | Sham, Shaharuddin Mohd
A survey among beachgoers was conducted to determine the swimming associated health effects experienced and its relationship with beach water exposure behaviour in Morib beach. For beach water exposure behaviour, the highest frequency of visit among the respondents was once a year (41.9%). For ways of water exposure, whole body exposure including head was the highest (38.5%). For duration of water exposure, 30.8% respondents prefer to be in water for about 30min with low possibilities of accidental ingestion of beach water. A total of 30.8% of beachgoers in Morib beach were reported of having dermal symptoms. Bivariate analysis showed only water activity, water contact and accidental ingestion of beach water showed significant association with swimming associated health effects experienced by swimmers. This study output showed that epidemiological study can be used to identify swimming associated health effects in beach water exposed to faecal contamination.
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