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A semi-automated Raman micro-spectroscopy method for morphological and chemical characterizations of microplastic litter
2016
L., Frère | I., Paul-Pont | J., Moreau | P., Soudant | C., Lambert | A., Huvet | E., Rinnert
Every step of microplastic analysis (collection, extraction and characterization) is time-consuming, representing an obstacle to the implementation of large scale monitoring. This study proposes a semi-automated Raman micro-spectroscopy method coupled to static image analysis that allows the screening of a large quantity of microplastic in a time-effective way with minimal machine operator intervention. The method was validated using 103 particles collected at the sea surface spiked with 7 standard plastics: morphological and chemical characterization of particles was performed in <3h. The method was then applied to a larger environmental sample (n=962 particles). The identification rate was 75% and significantly decreased as a function of particle size. Microplastics represented 71% of the identified particles and significant size differences were observed: polystyrene was mainly found in the 2–5mm range (59%), polyethylene in the 1–2mm range (40%) and polypropylene in the 0.335–1mm range (42%).
Show more [+] Less [-]Variations in nitrate isotope composition of wastewater effluents by treatment type in Hong Kong
2016
Archana, A. | Li, Luo | Shuh-Ji, Kao | Thibodeau, Benoit | Baker, David M.
Stable isotopes (δ15N, δ18O) can serve as tracers for sources of nitrogen in the receiving environment. Hong Kong discharges ~3×106m3d−1 of treated wastewater into the ocean from 68 facilities implementing preliminary to tertiary treatment. We sampled treated sewage from 18 plants across 5 treatment types and examined receiving seawater from northeast Hong Kong. We analyzed nitrate and nitrite (NO3−+NO2−, hereafter NOx) ammonium (NH4+), phosphate (PO4+) concentrations and δ15NNOx, δ18ONOx. Sewage effluents contained high mean nutrient concentrations (NO3−=260μmolL−1, NH4+=1400μmolL−1, PO4+=50μmolL−1) with some indication of nitrogen removal in advanced treatment types. Mean δ15NNOx of sewage effluents from all plants and treatment types (12‰) was higher than natural sources and varied spatially and seasonally. There was no overall effect of sewage treatment type on δ15NNOx. A mass balance model indicated that sewage (>68%) remains a dominant source of nitrate pollution in seawater in Tolo Harbor.
Show more [+] Less [-]Environmental sensitivity mapping and risk assessment for oil spill along the Chennai Coast in India
2016
Kankara, R.S. | Arockiaraj, S. | Prabhu, K.
Integration of oil spill modeling with coastal resource information could be useful for protecting the coastal environment from oil spills. A scenario-based risk assessment and sensitivity indexing were performed for the Chennai coast by integrating a coastal resource information system and an oil spill trajectory model. The fate analysis of spilled oil showed that 55% of oil out of a total volume of 100m3 remained in the water column, affecting 800m of the shoreline. The seasonal scenarios show major impact during the southwest (SW) and northeast (NE) monsoons and more fatal effects on marine pelagic organisms during SW monsoon. The Oil Spill Risk Assessment Modeler tool was constructed in a geographic information systems (GIS) platform to analyze the risks, sensitivity mapping, and priority indexing of resources that are likely to be affected by oil spills along the Chennai coast. The results of sensitivity mapping and the risk assessment results can help organizations take measures to combat oil spills in a timely manner.
Show more [+] Less [-]Comparison of heavy metal contamination during the last decade along the coastal sediment of Pakistan: Multiple pollution indices approach
2016
Saher, Noor Us | Siddiqui, Asmat Saleem
Heavy metals concentrations (Fe, Cu, Zn, Ni, Cr, Co, Pb, and Cd) were scrutinized during two monitoring years (2001 and 2011) in the coastal sediment of Pakistan. The status of metal contamination in coastal sediment was interpreted using sediment quality guidelines, and single and combined metal pollution indices. Ni, Cr, and Cd were recognized for their significant (p<0.05) intensification in the sediment during the last decade. Sediment quality guidelines recognized the frequent adverse biological effect of Ni and the occasional adverse biological effect of Cu, Cr, Pb and Cd. Single metal pollution indices (Igeo, EF, CF, and ER) revealed that sediment pollution is predominantly caused by Pb and Cd. Low to moderate contamination was appraised along the coast by multi-metal pollution indices (CD and PERI). Correlation study specifies that heavy metals were presented diverse affiliations and carriers for distribution in the sediment during the last decade.
Show more [+] Less [-]Assessment of metal enrichment and their bioavailability in sediment and bioaccumulation by mangrove plant pneumatophores in a tropical (Zuari) estuary, west coast of India
2016
Noronha-D'Mello, Cheryl A. | Nayak, G.N.
Sediment collected from the estuarine mangroves of the Zuari estuary and Cumbharjua canal were analyzed to assess the concentration, contamination and bioavailability of metals. Mangrove pneumatophores were also analyzed to understand the metal bioaccumulation in mangrove plants. The results indicated the variation of metal concentrations in sediment along the estuary was attributed to changing hydrodynamic conditions, type of sediment and metal sources. Further, speciation studies revealed that Fe, Cr, Co, Ni, Cu and Zn were mainly of lithogenic origin and less bioavailable while high Mn content in the sediment raised concerns over its potential mobility, bioavailability and subsequent toxicity. The mangrove plants exhibited difference in metal accumulation due to variations in sediment parameters and metal availability, in addition to difference in plant species and tissue physiology that affect metal uptake. Moreover, the mangrove plants reflected the quality of the underlying sediment and can be used as a potential bio-indicator tool.
Show more [+] Less [-]Combined nutrient and macroalgae loads lead to response in seagrass indicator properties
2016
Han, Qiuying | Soissons, Laura M. | Bouma, Tjeerd J. | van Katwijk, Marieke M. | Liu, Dongyan
Excess nutrients are potential factors that drive phase shifts from seagrasses to macroalgae. We carried out a manipulative field experiment to study the effects of macroalgae Ulva pertusa loading and nutrient addition to the water column on the nitrogen (N) and carbon (C) contents (i.e., fast indicators) as well as on the morphology and structure (i.e., slow indicators) of Zostera marina. Our results showed rapid impact of increased macroalgae and nutrient load on Z. marina C/N ratios. Also, macroalgae addition resulted in a trend of decreasing belowground biomass of seagrasses, and nutrient load significantly decreased above to belowground biomass ratio. Although some morphological/structural variables showed relatively fast responses, the effects of short-term disturbance by macroalgae and nutrients were less often significant than on physiological variables. Monitoring of seagrass physiological indicators may allow for early detection of eutrophication, which may initiate timely management interventions to avert seagrass loss.
Show more [+] Less [-]Study on the association between air pollution and mortality in İstanbul, 2007–2012
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 [-]Using an integrated approach to assess the sediment quality of an estuary from the semi-arid coast of Brazil
2016
Souza, Ivanildo Surini | Araujo, Giuliana Seraphim | Cruz, Ana Carolina Feitosa | Fonseca, Tainá Garcia | Camargo, Julia Beatriz Duarte Alves | Medeiros, Guilherme Fulgêncio | Abessa, Denis M.S.
The Jundiaí–Potengi Estuary (JPE) on the semi-arid coast of Brazil is influenced by multiple sources of pollution. Sediment quality at 10 JPE sites was evaluated through an integrated approach. Rainy and dry seasons were considered. Collected sediments were analyzed for texture, metal, nitrogen, phosphorus concentrations, and toxicity to invertebrates. Geochemical and ecotoxicological data were integrated using qualitative approaches and multivariate techniques. We observed decreased sediment quality in both seasons, particularly in the mid-estuary. In the dry season, the contamination–toxicity relationship was clearer, as hydrological conditions favor contaminant retention within the estuary. Rainy season conditions were found to be worse, since stormwater drainage from agricultural and urban areas carries the contamination into the estuary. Because of the contamination sources and dissolved and particle-bound metal transport, contamination and toxicity did not correlate as clearly in the rainy season. The results suggest that unmeasured contaminants are contributing to JPE sediment degradation.
Show more [+] Less [-]Trace/heavy metal pollution monitoring in estuary and coastal area of Bay of Bengal, Bangladesh and implicated impacts
2016
Kibria, Golam | Hossain, Md Maruf | Mallick, Debbrota | Lau, T.C. | Wu, R. S. S. (Rudolf Shiu-sun)
Using artificial mussels (AMs), this study reports and compares time-integrated level of eleven trace metals (Cd, Co, Cr, Cu, Fe, Hg, Mn, Ni, Pb, U, Zn) in Karnafuli River estuary and coastal area of the Bay of Bengal, Bangladesh.Through this study, “hot spots” of metal pollution were identified. The results may demonstrate that the Karnafuli Estuary, and adjacent coastal area of Chittagong, Bangladesh are highly polluted by high risk metals (cadmium, chromium, copper, mercury, nickel, lead, uranium). Agricultural, domestic and industrial wastes directly discharged into the waterways have been identified as the main causes of metal pollution in Chittagong, Bangladesh. The high level of metal pollution identified may impact on local water quality, and seafood catch, livelihoods of people and public health resulting from seafood consumption. There is a need for regular monitoring to ascertain that local water quality with respect to metal levels are within acceptable levels to safeguards both environmental health and public health.
Show more [+] Less [-]Succession in an intertidal benthic community affected by untreated sewage effluent: A case of study in the SW Atlantic shore
2016
Becherucci, M.E. | Llanos, E.N. | Garaffo, G.V. | Vallarino, E.A.
A study of benthic succession related with sewage pollution was conducted in a warm-temperate coastal area of Mar del Plata city, Argentina. The effect of nutrient enrichment and starting period of the succession was tested after cleared space in the intertidal rocky shore benthic community. The time of recovery after a disturbance in enriched sites was considerably lower (20–29weeks) than in non-enriched sites based on the diatom Berkeleya sp. and the polychaete Boccardia proboscidea developed in the early succession stage, and Brachidontes rodriguezii or B. proboscidea occurring with Polysiphonia sp., Petalonia fascia and Ulva spp. developed in the late succession stage of the enriched sites. The very low time at which the community recovered in the enriched environments turned out to be one of the assets of the present study and this parameter can be used as a quick indicator of sewage pollution in the area.
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