Calcium （Ca）, phosphorus （P）, and chitin are the main components of the exoskeleton of krill. Defluoridation of a solution of sodium fluoride （NaF） using calcium phosphate （Ca3（PO4）2） and chitin as defluorid...Calcium （Ca）, phosphorus （P）, and chitin are the main components of the exoskeleton of krill. Defluoridation of a solution of sodium fluoride （NaF） using calcium phosphate （Ca3（PO4）2） and chitin as defluoridation agents was studied. Orthogonal experiments were designed to find the optimum reaction conditions for defluoridation, to obtain the maximum defluoridation efficiency and fluoride removal capacity of calcium phosphate and chitin. At the same time, a comparison of the capacity of the two defluoridation agents was made. The results suggest that calcium phosphate has a far greater capability than chitin for the removal of fluoride （F） from water under similar reaction conditions. It is also suggested that Antarctic krill is likely to adsorb fluoride via compounds such as calcium phosphate, hydroxyapatite, and other compounds of Ca and P with the general form （Ca, X）x（PO4, HPO4, Y）y（OH, Z）z, in addition to chitin.展开更多
Antarctic krill are a potential food source for humans and animals, but krill are known to contain high levels of fluorine （F）. In this study, we investigated the toxicity of F in Antarctic krill using Wistar rats. ...Antarctic krill are a potential food source for humans and animals, but krill are known to contain high levels of fluorine （F）. In this study, we investigated the toxicity of F in Antarctic krill using Wistar rats. There were three experimental groups： The control group were fed a basal diet, the krill treatment group were fed the same basal diet mixed with krill powder （150 mg＇kg-~ F）, and the sodium fluoride （NaF） treatment group were fed the basal diet with added NaF （150 mg.kg1 F）. General toxicity indicators including body weight and food intake were measured during the experiment. After three months the rats were dissected and tissue samples were collected from the liver, kidney, spleen, brain, and testis. Morphological changes in the cells of these tissues were assessed using HE staining. There were no significant differences in the body weight, the food intake, or the viscera coefficients among the three groups. In both treatment groups some pathological changes were observed in all soft tissue samples except the testis, although there were fewer and less severe pathological changes in the krill treatment group than in the NaF treatment group. The results showed that the toxicity of F in Antarctic krill was lower than for an equivalent amount of F in NaF, but it was still toxic to rats consuming large quantities of krill. The findings of this study highlight the need for further investigation into potential F toxicity if krill is to be used for human consumption.展开更多
The levels and depth distributions of As, Cd, Cu, Zn, Pb, Hg, Fe and Mn in two sediment cores DY2 and DY4 collected from the ＂Cattle Pond＂ of Dongdao Island, South China Sea, were determined and analyzed with the ma...The levels and depth distributions of As, Cd, Cu, Zn, Pb, Hg, Fe and Mn in two sediment cores DY2 and DY4 collected from the ＂Cattle Pond＂ of Dongdao Island, South China Sea, were determined and analyzed with the main objective to identify the sources of these elements and evaluate the corresponding sedimentological and geochemical processes. Lithological characters and sedimentary parameters such as LOI950℃, CaO, LOI550℃ and TOC indicate that the depth of 96 cm and 87 cm are the critical points for DY2 and DY4 cores, respectively. As, Cd, Cu, Zn, Hg and P are remarkably enriched in the ornithogenic sediments above the critical depth points; their concentration-versus-depth profiles are similar to those of TOC and LOI550℃; the ratios of As, Cd, Cu, Zn, Hg over Ca are significantly correlated with P/Ca. Statistical and comparative analyses of these elements＇ levels in the ornithogenic sediments of DY2 and DY4 strongly suggest that seabird droppings are the main source of these elements. Additionally, for the upper sediment layers of DY2 and DY4 cores, Fe oxide sorption mechanism, like organic matter, may also play an important role in the abundances of heavy metals. Heavy metal Pb has geochemical characteristics distinctly different from those of As, Cd, Cu, Zn, Hg and P, and its isotope composition indicates an origin of anthropogenic emissions from the surrounding countries. These geochemical characteristics in the orinithogenic sediments of Xisha Islands are compared with the studies in the remote Antarctic and Arctic regions.展开更多
Antarctic krill is a potentially nutritious food source for humans, but lfuorine （F） toxicity is a matter of concern. To evaluate the toxicity of F in Antarctic krill, 30 Wistar rats were divided into three groups w...Antarctic krill is a potentially nutritious food source for humans, but lfuorine （F） toxicity is a matter of concern. To evaluate the toxicity of F in Antarctic krill, 30 Wistar rats were divided into three groups with different dietary regimens：a control group, a krill treatment group （150 mg＆#183;kg-1 F）, and a sodium lfuoride （NaF） treatment group （150 mg＆#183;kg-1 F）. After three months, F concentrations in feces, plasma, and bone were determined, and the degree of dental and skeletal lfuorosis was assessed. The F concentrations in plasma and bone from the krill treatment group were 0.167 0＆#177;0.020 4 mg.L-1 and 2 709.8＆#177;301.9 mg＆#183;kg-1, respectively, compared with 0.043 8＆#177;0.005 5 mg＆#183;L-1 and 442.4＆#177;60.7 mg＆#183;kg-1, respectively, in samples from the control group. Concentrations of F in plasma and bone in the krill treatment group were higher than in the control group, but lower than in the NaF treatment group. The degree of dental lfuorosis in the krill treatment group was moderate, compared with severe in the NaF treatment group and normal in the control group. The degree of skeletal lfuorosis did not change signiifcantly in any group. These results showed that the toxicity of F in Antarctic krill was lower than for an equivalent concentration of F in NaF, but it was toxic for rats consuming krill in large quantities. To conclude, we discuss possible reasons for the reduced toxicity of F in Antarctic krill. The present study provides a direct toxicological reference for the consideration of Antarctic krill for human consumption.展开更多
基金Financial support from the National Natural Science Foundation of China(Grant nos.40601088,40476001 and 40231002)the Open Research Fund from the Key Laboratory of Polar Science,State Oceanic Administration,P.R.China(Grant no.KP201106)
文摘Calcium （Ca）, phosphorus （P）, and chitin are the main components of the exoskeleton of krill. Defluoridation of a solution of sodium fluoride （NaF） using calcium phosphate （Ca3（PO4）2） and chitin as defluoridation agents was studied. Orthogonal experiments were designed to find the optimum reaction conditions for defluoridation, to obtain the maximum defluoridation efficiency and fluoride removal capacity of calcium phosphate and chitin. At the same time, a comparison of the capacity of the two defluoridation agents was made. The results suggest that calcium phosphate has a far greater capability than chitin for the removal of fluoride （F） from water under similar reaction conditions. It is also suggested that Antarctic krill is likely to adsorb fluoride via compounds such as calcium phosphate, hydroxyapatite, and other compounds of Ca and P with the general form （Ca, X）x（PO4, HPO4, Y）y（OH, Z）z, in addition to chitin.
基金financial support provided by the Open Research Fund from the SOA Key Laboratory for Polar Science,China (Grant no.KP201106)
文摘Antarctic krill are a potential food source for humans and animals, but krill are known to contain high levels of fluorine （F）. In this study, we investigated the toxicity of F in Antarctic krill using Wistar rats. There were three experimental groups： The control group were fed a basal diet, the krill treatment group were fed the same basal diet mixed with krill powder （150 mg＇kg-~ F）, and the sodium fluoride （NaF） treatment group were fed the basal diet with added NaF （150 mg.kg1 F）. General toxicity indicators including body weight and food intake were measured during the experiment. After three months the rats were dissected and tissue samples were collected from the liver, kidney, spleen, brain, and testis. Morphological changes in the cells of these tissues were assessed using HE staining. There were no significant differences in the body weight, the food intake, or the viscera coefficients among the three groups. In both treatment groups some pathological changes were observed in all soft tissue samples except the testis, although there were fewer and less severe pathological changes in the krill treatment group than in the NaF treatment group. The results showed that the toxicity of F in Antarctic krill was lower than for an equivalent amount of F in NaF, but it was still toxic to rats consuming large quantities of krill. The findings of this study highlight the need for further investigation into potential F toxicity if krill is to be used for human consumption.
基金the key project of National Natural Science Foundation of China(No.40730107 and 40606003）.
文摘The levels and depth distributions of As, Cd, Cu, Zn, Pb, Hg, Fe and Mn in two sediment cores DY2 and DY4 collected from the ＂Cattle Pond＂ of Dongdao Island, South China Sea, were determined and analyzed with the main objective to identify the sources of these elements and evaluate the corresponding sedimentological and geochemical processes. Lithological characters and sedimentary parameters such as LOI950℃, CaO, LOI550℃ and TOC indicate that the depth of 96 cm and 87 cm are the critical points for DY2 and DY4 cores, respectively. As, Cd, Cu, Zn, Hg and P are remarkably enriched in the ornithogenic sediments above the critical depth points; their concentration-versus-depth profiles are similar to those of TOC and LOI550℃; the ratios of As, Cd, Cu, Zn, Hg over Ca are significantly correlated with P/Ca. Statistical and comparative analyses of these elements＇ levels in the ornithogenic sediments of DY2 and DY4 strongly suggest that seabird droppings are the main source of these elements. Additionally, for the upper sediment layers of DY2 and DY4 cores, Fe oxide sorption mechanism, like organic matter, may also play an important role in the abundances of heavy metals. Heavy metal Pb has geochemical characteristics distinctly different from those of As, Cd, Cu, Zn, Hg and P, and its isotope composition indicates an origin of anthropogenic emissions from the surrounding countries. These geochemical characteristics in the orinithogenic sediments of Xisha Islands are compared with the studies in the remote Antarctic and Arctic regions.
基金the financial support of the Open Research Fund from the Key Laboratory for Polar Science,State Oceanic Administration,P.R.China(Grant no.KP201106)the Research Industry Joint Innovation Project of Jiangsu(Grant no.BY2011186)
文摘Antarctic krill is a potentially nutritious food source for humans, but lfuorine （F） toxicity is a matter of concern. To evaluate the toxicity of F in Antarctic krill, 30 Wistar rats were divided into three groups with different dietary regimens：a control group, a krill treatment group （150 mg＆#183;kg-1 F）, and a sodium lfuoride （NaF） treatment group （150 mg＆#183;kg-1 F）. After three months, F concentrations in feces, plasma, and bone were determined, and the degree of dental and skeletal lfuorosis was assessed. The F concentrations in plasma and bone from the krill treatment group were 0.167 0＆#177;0.020 4 mg.L-1 and 2 709.8＆#177;301.9 mg＆#183;kg-1, respectively, compared with 0.043 8＆#177;0.005 5 mg＆#183;L-1 and 442.4＆#177;60.7 mg＆#183;kg-1, respectively, in samples from the control group. Concentrations of F in plasma and bone in the krill treatment group were higher than in the control group, but lower than in the NaF treatment group. The degree of dental lfuorosis in the krill treatment group was moderate, compared with severe in the NaF treatment group and normal in the control group. The degree of skeletal lfuorosis did not change signiifcantly in any group. These results showed that the toxicity of F in Antarctic krill was lower than for an equivalent concentration of F in NaF, but it was toxic for rats consuming krill in large quantities. To conclude, we discuss possible reasons for the reduced toxicity of F in Antarctic krill. The present study provides a direct toxicological reference for the consideration of Antarctic krill for human consumption.
