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Analysis of a decade of Asian outflow of PM10 and TSP to Gosan, Korea; also incorporating Radon–222 全文
2015
Crawford, Jagoda | Chambers, Scott | Kang, Ch'ang-hŭi | Griffiths, Alan | Kim, Won-Hyung
Ten years of aerosol and Radon–222 (radon) data from Gosan, Korea, were analyzed. Seasonal cycles were strongly linked to changes in fetch and time of year. We estimated that 7.21t/m y of PMio aerosol pass Gosan in the atmospheric boundary layer, increasing annually by 0.3t/m y. Contributions to aerosol loading were characterized by fetch: South China, North China, Korea and Japan. While the highest, and most variable, contributions typically originated from South China, these air masses contributed to only 6% of the overall dataset. PM10 distributions were broader from South and North China than for Korea or Japan, reflecting differences in natural/anthropogenic soil sources, and number/distribution of large point sources. Employing radon to select air masses more representative of targeted fetch regions typically resulted in greater reported pollutant concentrations and rates of change over the decade. Estimated rates of PM10 increase from North China and Korea over the decade were 1.4 and 0.9μg/m3 y, respectively. Total suspended particulate (TSP) elemental analysis indicated that the (non–sea–salt) nss–SO42− content of aerosols has been gradually increasing over the past decade and more recently an increase in NO3− was seen. However, on average, rates of increase in nss–SO42− have reduced since 2007, which were higher in South than North China.
显示更多 [+] 显示较少 [-]Water quality assessment using water quality index and geographical information system methods in the coastal waters of Andaman Sea, India 全文
2015
Jha, Dilip Kumar | Devi, Marimuthu Prashanthi | Vidyalakshmi, Rajendran | Brindha, Balan | Vinithkumar, Nambali Valsalan | Kirubagaran, Ramalingam
Seawater samples at 54 stations in the year 2011–2012 from Chidiyatappu, Port Blair, Rangat and Aerial Bays of Andaman Sea, have been investigated in the present study. Datasets obtained have been converted into simple maps using coastal water quality index (CWQI) and Geographical Information System (GIS) based overlay mapping technique to demarcate healthy and polluted areas. Analysis of multiple parameters revealed poor water quality in Port Blair and Rangat Bays. The anthropogenic activities may be the likely cause for poor water quality. Whereas, good water quality was witnessed at Chidiyatappu Bay. Higher CWQI scores were perceived in the open sea. However, less exploitation of coastal resources owing to minimal anthropogenic activity indicated good water quality index at Chidiyatappu Bay. This study is an attempt to integrate CWQI and GIS based mapping technique to derive a reliable, simple and useful output for water quality monitoring in coastal environment.
显示更多 [+] 显示较少 [-]Trace metal variability in coastal waters of San Jorge Bay, Antofagasta, Chile: An environmental evaluation and statistical approach to propose local background levels 全文
2015
Valdés, J. | Román, D. | Guiñez, M. | Rivera, L. | Ávila, J. | Cortés, P. | Castillo, A.
Between 2008 and 2011, twelve metals from 384 coastal waters samples from San Jorge Bay (Antofagasta, northern Chile) were collected and analyzed. The goal was to evaluate the quality of the bay's water bodies according to the current Chilean Quality Guideline and to establish background levels for these metals.The result suggests that the coastal waters of San Jorge Bay are of very good quality suitable for recreational activities involving human body contact. The natural background thresholds established for this bay were significantly lower than primary and secondary water quality guidelines. The distribution of Cu, Zn and Pb, along the bay's coastline provides evidence of the effects of industrial activity. Both situations suggest that the threshold indicated in the environmental guidelines of the Chilean legislation may be overestimated and do not represent pollution-free environments.
显示更多 [+] 显示较少 [-]Heavy metals and TPH effects on microbial abundance and diversity in two estuarine areas of the southern-central coast of São Paulo State, Brazil 全文
2015
Pinto, Aline Bartelochi | Pagnocca, Fernando Carlos | Pinheiro, Marcelo Antonio Amaro | Fontes, Roberto Fioravanti Carelli | Oliveira, Ana Júlia Fernandes Cardoso de
Coastal areas may be impacted by human and industrial activities, including contamination by wastewater, heavy metals and hydrocarbons. This study aimed to evaluate the impact of hydrocarbons (TPH) and metals on the microbiota composition and abundance in two estuarine systems in the coast of São Paulo: the Santos (SE) and Itanhaém (IE) estuaries. The SE was found to be chronically contaminated by heavy metals and highly contaminated by hydrocarbons. This finding was correlated with the increased density of cyanobacteria in sediments and suggests the possible use of cyanobacteria for bioremediation. These contaminants influence the density and composition of estuarine microbiota that respond to stress caused by human activity. The results are troubling because quantitative and qualitative changes in the microbiota of estuarine sediments may alter microbiological processes such as decomposition of organic matter. Moreover, this pollution can result in damage to the environment, biota and human health.
显示更多 [+] 显示较少 [-]Multivariate and geo-spatial approach for seawater quality of Chidiyatappu Bay, south Andaman Islands, India 全文
2015
Jha, Dilip Kumar | Vinithkumar, Nambali Valsalan | Sahu, Biraja Kumar | Dheenan, Palaiya Sukumaran | Das, Apurba Kumar | Begum, Mehmuna | Devi, Marimuthu Prashanthi | Kirubagaran, Ramalingam
Chidiyatappu Bay is one of the least disturbed marine environments of Andaman & Nicobar Islands, the union territory of India. Oceanic flushing from southeast and northwest direction is prevalent in this bay. Further, anthropogenic activity is minimal in the adjoining environment. Considering the pristine nature of this bay, seawater samples collected from 12 sampling stations covering three seasons were analyzed. Principal Component Analysis (PCA) revealed 69.9% of total variance and exhibited strong factor loading for nitrite, chlorophyll a and phaeophytin. In addition, analysis of variance (ANOVA-one way), regression analysis, box-whisker plots and Geographical Information System based hot spot analysis further simplified and supported multivariate results. The results obtained are important to establish reference conditions for comparative study with other similar ecosystems in the region.
显示更多 [+] 显示较少 [-]Mercury concentrations in Atlantic bottlenose dolphins (Tursiops truncatus) inhabiting the Indian River Lagoon, Florida: Patterns of spatial and temporal distribution 全文
2015
Schaefer, Adam M. | Titcomb, Elizabeth Murdoch | Fair, Patricia A. | Stavros, Hui-Chen W. | Mazzoil, Marilyn | Bossart, Gregory D. | Reif, John S.
Bottlenose dolphins (Tursiops truncatus) inhabiting the Indian River Lagoon, FL (IRL) have tissue mercury concentrations among the highest reported worldwide. Analysis of total mercury (THg) concentrations in blood collected between 2003 and 2012 showed a significant linear decrease over time (p=0.04). Significant differences in the spatial distribution of THg in resident IRL dolphins were also observed with a general gradient in concentration from north to south. Evaluation of local biogeochemistry and accumulation of mercury in prey species is needed to better understand factors influencing the distribution of Hg in the apex predator. Analyses of temporal and spatial patterns of exposure to THg in this sentinel species may have implications for both ecosystem and public health in the region.
显示更多 [+] 显示较少 [-]Distribution and assessment of heavy metals off the Changjiang River mouth and adjacent area during the past century and the relationship of the heavy metals with anthropogenic activity 全文
2015
Hu, Gang | Bi, Shipu | Xu, Gang | Zhang, Yong | Mei, Xi | Li, Anchun
Forty-three surface sediment samples and one gravity core obtained from the offshore area of the Changjiang River were analyzed for selected heavy metals (Cu, Pb, Zn, Cd, As, Hg) to evaluate the spatial distribution and potential ecological risk during the last century. The results indicated that the sediments are composed of silty sand, sandy silt and silt and were deposited in a relatively stable environment over the last century. The studied marine sediments are fine and easily adsorb heavy metals from aquatic systems. The heavy metal concentrations were found to be enriched in the sediments and were generally closely related to anthropogenic activities. However, the data analysis demonstrated that the levels of heavy metal contamination were below background values during the last century, indicating low ecological risk. Spatially, a higher concentration was found at the entrance to the Changjiang River, while it decreased to the northeast. The vertical distribution of contamination levels and ecological risk can be divided into four periods based on the downcore variation in heavy metals: pre-1940s, 1940s–1970s, 1970s–1990s and the late 1990s to the present. These conclusions form the basis for implementing appropriate policies to protect marine sediment quality.
显示更多 [+] 显示较少 [-]Assessment of metal contamination in coastal sediments of the Maluan Bay (China) using geochemical indices and multivariate statistical approaches 全文
2015
Wang, Zaosheng | Wang, Yushao | Chen, Liuqin | Yan, Changzhou | Yan, Yijun | Chi, Qiaoqiao
Total concentrations and chemical forms of heavy metals in surface sediments of Maluan Bay were determined and multiple geochemical indices and guidelines were applied to assess potential contamination and environmental risks. Metal concentrations exhibited significant spatial variation and the speciation of Cr was presented dominantly in the residual fraction, while Cd was found mostly in the non-residual fraction and thus of high potential bioavailability. Cluster analysis separated four subgroups of sampling sites with different levels of contamination. Further, a multivariate method offered the specific interpretation of possible contaminant sources and/or pathways. Factor scores characterized the sampling locations and elucidated the pollution status, pointing out the impact of multiple “hidden hotspots” of contaminants and providing further evidence of the existence of clear pollution-risk gradients in lagoon areas. The study supports the integrative approach as powerful tool to diagnose the pollution status scientifically for management decisions in coastal sediment of complex environment.
显示更多 [+] 显示较少 [-]Trace elements in eggs of common eiders (Somateria mollissima) breeding in Nova Scotia, Canada 全文
2015
Pratte, Isabeau | Tomlik, Molly D. | Betsch, Taylor A. | Braune, Birgit M. | Milton, G Randy | Mallory, Mark L.
We provide the first report on trace element concentrations in eggs of common eiders (Somateria mollissima), a coastal benthic foraging sea duck, from Nova Scotia, Canada, and compare those to known values from this species elsewhere. Most trace elements of toxicological concern (Hg, Se, Cd, Cu, Zn) were lower in eider eggs from Nova Scotia than from eider eggs collected farther north in Canada, although As was elevated. Our data provide strong support for a pattern of increasing Hg at higher latitudes for this species.
显示更多 [+] 显示较少 [-]Changes in abundance and composition of anthropogenic marine debris on the continental slope off the Pacific coast of northern Japan, after the March 2011 Tohoku earthquake 全文
2015
Goto, Tomoaki | Shibata, Haruka
Abundance and composition of anthropogenic marine debris were assessed on the basis of six bottom trawl surveys conducted on the continental slope off Iwate Prefecture, Pacific coast of northern Japan, in 2003, 2004 and 2011, and the temporal changes due to the Tohoku earthquake and tsunami in March 2011 evaluated. In 2003 and 2004, 54–94 items km−2 of marine debris, dominated by sea-base sourced items mainly comprising fishing gear and related items from adjacent fishing grounds on the continental shelf, were quantified. In the post-earthquake period, the density increased drastically to 233–332 items km−2, due to an increase in land-base sourced items generated by the tsunami. However, a major increase in abundance after the disaster, compared to the total amount of tsunami debris swept into the sea, was not found. Additional sources of land-based debris from the adjacent continental shelf are suggested in the present waters.
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