Уточнить поиск
Результаты 1121-1130 из 4,044
The monetary valuation of acute respiratory illness from air pollution in Turkey Полный текст
2016
Ara, Shihomi | Tekeşin, Cem
A contingent valuation study is conducted in three locations in Turkey using a total of 1362 observations to elicit willingness to pay (WTP) to avoid the acute respiratory illness (three days of severe coughing and throat pain). This is the first research of this kind in Turkey, and also one of a few studies conducted in developing countries. Median WTPs are estimated as 65, 51, and 83 PPP-adjusted 2012 USD for Afsin-Elbistan, Kutahya-Tavsanli and Ankara, respectively. Income elasticities of WTP are derived as 0.8 for Afsin-Elbistan and tested statistically indifferent from 1.0 for Kutahya-Tavsanli, and Ankara, and are found to be greater than the cases in existing studies conducted both in developed and developing countries. We also find that 60 to 90 percent of WTP are devoted for avoiding pain and discomfort/restricted activity days, and much less weights are given for avoiding possible financial losses. As for the determinants of WTP, university graduates, those who have experienced coughing within one month, have spent out-of-pocket medical expenses and actually lost some part of their income due the last experienced minor symptoms are willing to pay more to avoid the future acute respiratory illness while women and the household using coal as the main source of home-heating are willing to pay less in one or more study areas. New air quality standard for PM10 (transition from 150 μg/m3 to 40 μg/m3 by 2019) causes the reductions in minor respiratory symptoms by 11, 8, and 4.4 per person, and the resulting welfare gains are calculated as 157 million, 123 million, and 1464 million PPP-adjusted 2012 USD for Afsin-Elbistan, Kutahya-Tavsanli and Ankara, respectively.
Показать больше [+] Меньше [-]Islands in the oil: Quantifying salt marsh shoreline erosion after the Deepwater Horizon oiling Полный текст
2016
Turner, R Eugene | McClenachan, Giovanna | Tweel, Andrew W.
Qualitative inferences and sparse bay-wide measurements suggest that shoreline erosion increased after the 2010 BP Deepwater Horizon (DWH) disaster, but quantifying the impacts has been elusive at the landscape scale. We quantified the shoreline erosion of 46 islands for before and after the DWH oil spill to determine how much shoreline was lost, if the losses were temporary, and if recovery/restoration occurred. The erosion rates at the oiled islands increased to 275% in the first six months after the oiling, were 200% of that of the unoiled islands for the first 2.5years after the oiling, and twelve times the average land loss in the deltaic plain of 0.4%y−1 from 1988 to 2011. These results support the hypothesis that oiling compromised the belowground biomass of the emergent vegetation. The islands are, in effect, sentinels of marsh stability already in decline before the oil spill.
Показать больше [+] Меньше [-]Effects of hypoxia caused by mussel farming on benthic foraminifera in semi-closed Gamak Bay, South Korea Полный текст
2016
Lee, Yeon Gyu | Jeong, Da Un | Lee, Jung Sick | Choi, Yang Ho | Lee, Moon-ok
Seawater monitoring and geochemical and benthic foraminiferal analysis of sediments were conducted to identify the effects of hypoxia created by a mussel farm on benthic foraminifera in a semi-closed bay. Extremely polluted reductive conditions with a high content of organic matter (OM) at >12.0% and oxygen minimum zones (OMZs) with dissolved oxygen (DO) <0.4mg∙L–1 were formed below the mussel farm in the northwest area of Gamak Bay, and gradually diffused toward the south. Highly similar patterns of variation were observed in species diversity, abundance frequency, and benthic foraminiferal assemblage distributed from Elphidium subarcticum–Ammonia beccarii in the northwest area through E. subarcticum–A. beccarii–Trochammina hadai, E. subarcticum–A. beccarii–Elphidiumclavatum, and E. clavatum–Ammonia ketienziensis in the southern area. These phenomena were caused by hydrodynamics in the current water mass. It was thought that E. subarcticum is a bioindicator of organic pollution caused by the mussel farm.
Показать больше [+] Меньше [-]Bioaugmentation strategy employing a microbial consortium immobilized in chitosan beads for oil degradation in mesocosm scale Полный текст
2016
Dellagnezze, B.M. | Vasconcellos, S.P. | Angelim, A.L. | Melo, V.M.M. | Santisi, S. | Cappello, S. | Oliveira, V.M.
A bacterial consortium composed by four metagenomic clones and Bacillus subtilis strain CBMAI 707, all derived from petroleum reservoirs, was entrapped in chitosan beads and evaluated regarding hydrocarbon degradation capability. Experiments were carried out in mesocosm scale (3000L) with seawater artificially polluted with crude oil. At different time intervals, mesocosms were sampled and subjected to GC-FID and microbiological analyses, as total and heterotrophic culturable bacterial abundance (DAPI and CFU count), biological oxygen demand (BOD) and taxonomic diversity (massive sequencing of 16S rRNA genes). The results obtained showed that degradation of n-alkane hydrocarbons was similar between both treatments. However, aromatic compound degradation was more efficient in bioaugmentation treatment, with biodegradation percentages reaching up to 99% in 30days. Community dynamics was different between treatments and the consortium used in the bioaugmentation treatment contributed to a significant increase in aromatic hydrocarbon degradation.
Показать больше [+] Меньше [-]Heavy metal accumulation in surface sediments at the port of Cagliari (Sardinia, western Mediterranean): Environmental assessment using sequential extractions and benthic foraminifera Полный текст
2016
Schintu, Marco | Marrucci, Alessandro | Marras, Barbara | Galgani, François | Buosi, Carla | Ibba, Angelo | Cherchi, A. (Antonietta)
Superficial sediments were taken at the port of Cagliari (Sardinia, Italy), which includes the oil terminal of one of the largest oil refineries in the Mediterranean. Significant trace metal concentrations were found in the whole port area. Sequential extraction of metals from the different sediment fractions (BCR method) showed a higher risk of remobilisation for Cd, which is mostly bound to the exchangeable fraction. Foraminiferal density and richness of species were variable across the study area. The living assemblages were characterized by low diversity in samples collected close to the port areas. Ammonia tepida and bolivinids, which were positively correlated with concentrations of heavy metals and organic matter content, appeared to show tolerance to the environmental disturbance. The sampling sites characterized by the highest values of biotic indices were located far from the port areas and present an epiphytic and epifaunal biocoenosis.
Показать больше [+] Меньше [-]Application of novel image base estimation of invisible leaf injuries in relation to morphological and photosynthetic changes of Phaseolus vulgaris L. exposed to tropospheric ozone Полный текст
2016
Drapikowska, M. | Drapikowski, P. | Borowiak, K. | Hayes, F. | Harmens, H. | Dziewiątka, T. | Byczkowska, K.
This study aimed to evaluate the degree of Phaseolus vulgaris L. (bean) leaf tissue injury caused by tropospheric ozone. To validate O3 symptoms at the microscopic level, Evans blue staining together with an image processing method for the removal of distortions and calculation of dead leaf areas was applied. Net photosynthetic rate (PN), stomatal conductance (gs) and intercellular CO2 concentration (Ci) were determined to evaluate leaf physiological responses to ozone. It was found that both resistant and sensitive varieties of bean were damaged by ozone; however, the size of necrotic and partially destroyed leaf area in the sensitive genotype (S156) was bigger (1.18%, 2.18%) than in the resistant genotype (R123), i.e. 0.02% and 0.50%. Values of net photosynthetic rates were lower in the sensitive genotype in ambient air conditions, than in the resistant genotype in ambient air conditions. We further found that there was a correlation between physiological and anatomical injuries; net photosynthetic rate (PN) was negatively correlated with percentage of necrotic area of both genotypes, while stomatal conductance (gs), intercellular CO2 concentration (Ci) were positively correlated with percentage of necrotic tissue of both genotypes. Moreover, visible injures in both genotypes were positively correlated with percentage of anatomical injures. In conclusion, the presented combinations of morphological, anatomical and physiological markers allowed differential diagnosis of ozone injury.
Показать больше [+] Меньше [-]Nutrient distribution and structure affect the acidification of eutrophic ocean margins: A case study in southwestern coast of the Laizhou Bay, China Полный текст
2016
Zhang, Jinfeng | Gao, Xuelu
The effects of nutrient distribution and structure on the acidity of coastal waters were analyzed based on the data of 48 surface water samples collected in the southwestern coast of the Laizhou Bay and its adjacent rivers (SWLZB) which are heavily influenced by nutrient-laden discharges. The concentration and structure of nutrients varied considerably along the coast owing to different contributors. The studied inshore waters exhibited a sign of acidification. The pH was significantly negatively correlated with the concentration of NO3-N, NO2-N, NH4-N and DSi, but showed no obvious correlation with the concentration of PO4-P and the ratio of TDN/TDP, DSi/DIN and DSi/PO4-P, respectively. The results indicated that the distribution of nutrients might well be an important environmental factor affecting the acidification of the SWLZB in warmer months.
Показать больше [+] Меньше [-]Anthropogenic microfibres pollution in marine biota. A new and simple methodology to minimize airborne contamination Полный текст
2016
Torre, Michele | Digka, Nikoletta | Anastasopoulou, Aikaterini | Tsangaris, Catherine | Mytilineou, Chryssi
Research studies on the effects of microlitter on marine biota have become more and more frequent the last few years. However, there is strong evidence that scientific results based on microlitter analyses can be biased by contamination from air transported fibres. This study demonstrates a low cost and easy to apply methodology to minimize the background contamination and thus to increase results validity. The contamination during the gastrointestinal content analysis of 400 fishes was tested for several sample processing steps of high risk airborne contamination (e.g. dissection, stereomicroscopic analysis, and chemical digestion treatment for microlitter extraction). It was demonstrated that, using our methodology based on hermetic enclosure devices, isolating the working areas during the various processing steps, airborne contamination reduced by 95.3%. The simplicity and low cost of this methodology provide the benefit that it could be applied not only to laboratory but also to field or on board work.
Показать больше [+] Меньше [-]Plastic debris in great skua (Stercorarius skua) pellets corresponds to seabird prey species Полный текст
2016
Hammer, S. | Nager, R.G. | Johnson, P.C.D. | Furness, R.W. | Provencher, J.F.
Plastic is a common item in marine environments. Studies assessing seabird ingestion of plastics have focused on species that ingest plastics mistaken for prey items. Few studies have examined a scavenger and predatory species that are likely to ingest plastics indirectly through their prey items, such as the great skua (Stercorarius skua). We examined 1034 regurgitated pellets from a great skua colony in the Faroe Islands for plastics and found approximately 6% contained plastics. Pellets containing remains of Northern fulmars (Fulmarus glacialis) had the highest prevalence of plastic. Our findings support previous work showing that Northern fulmars have higher loads of plastics than other sympatric species. This study demonstrates that marine plastic debris is transferred from surface feeding seabird species to predatory great skuas. Examination of plastic ingestion in species that do not ingest plastics directly can provide insights into how plastic particles transfer vertically within the food web.
Показать больше [+] Меньше [-]Transcriptomic response to water accommodated fraction of crude oil exposure in the gill of Japanese flounder, Paralichthys olivaceus Полный текст
2016
Zhu, Lin | Qu, Keming | Xia, Bin | Sun, Xuemei | Chen, Bijuan
Illumina-based RNA-seq was used to determine the short-term transcriptomic responses of Paralichthys olivaceus gill to an environmentally relevant level of water accommodated fraction (WAF) of crude oil. 213,979 transcripts and 128,482 unigenes were obtained. Differential expression analysis revealed that 1641 and 2142 genes were significantly up- and down-regulated. Enrichment analysis identified a set of GO terms and putative pathways involved in the response of P. olivaceus to WAF exposure. Analysis of the transcripts revealed the effective protective mechanisms of P. olivaceus to reduce the toxic effects of WAF. Moreover, WAF exposure induced the metabolism of energy substrates, and downstream pathway genes were modified to provide protection against toxic damage. Transcripts analysis demonstrated that the genes involved in circadian rhythm signaling were regulated in gills of P. olivaceus exposed to WAF. These results provide insights into the mechanisms of WAF-induced toxicity in fishes and into the WAF-sensitive biomarkers in P. olivaceus.
Показать больше [+] Меньше [-]