[Temporal and Spatial Characteristics of Heavy Metals in Suspended Particulate Matter in Pearl River Estuary and Its Influencing Factors].

Simultaneous sampling and observation were conducted at 16 stations in the Pearl River Estuary, and the temporal and spatial characteristics of the contents of six heavy metals (Cr, Cu, Zn, Pb, As, and Cd) were analyzed. The influencing factors of suspended particulate matter (SPM) were explored through the combined results of our statistical analyses. With the influence of discharge, temperature and particle size, the content of heavy metals in the dry season is higher than that in flood season. Regarding the estuary filter, the content of heavy metals in the estuary segment was lower than that in the far mouth segment, which was principally caused by the difference in salinity and sediment concentration between the two segments during the dry season. Both the sediment quality standard and enrichment factor methods were used to evaluate heavy metals. The results showed that the threat of heavy metals in the dry season was stronger than that in the flood season. As and Zn were more harmful to the ecological risk, while Cd, As, and Zn were the more abundant pollutants in the Pearl River Estuary. Heavy metal pollution was more severe in the far mouth segment. The degree of pollution for Cu, Zn, As, and Cd- which are classified as heavy pollution, severe to extremely heavy pollution, severe heavy pollution, and extremely heavy pollution, respectively-in the Beijiang River were higher compared to the Xijiang River and Dongjiang River. The pollution level of the six heavy metals in the four eastern outlets and four western outlets were similar, and the most serious pollution in Humen may be related to local industrial development. The source of heavy metals in SPM of the Pearl River Estuary is related to geological background, industry, and the mining area.

[Effect of Yunnan herb Laggera pterodonta against influenza A (H1N1) virus in vitro].

Laggera pterodonta is commonly used for treating influenza in Southwest China, especially in Yunnnan province. The main clinical effects of L. pterodonta include anti-influenza, anti-microbial, anti-inflammatory. To investigate the anti-influenza A (H1N1) virus effect of L. pterodonta, neutralization inhibition and proliferation inhibition tests were performed. MDCK culture method was used to observe the cytopathic effect (CPE) of extracts from L. pterodonta in inhibiting influenza A (H1N1) virus and haemagglutination titre of H1N1 virus in vitro. The culture medium were collected at 24 h, 48 h, 72 h, 96 h, and detected by Real time RT-PCR, in order to compare the effect of different extracts from L. pterodonta on in vitro proliferation of H1N1, virus. The result of neutralization inhibition test showed that hemagglutination titer of ethyl acetate extract were 8 times lower at 72 h; in proliferation inhibition test, hemagglutination titer of ethyl acetate extracts reduced by 2 and 4 times. According to the results of Real time RT-PCR test, the H1N1 inhibition ratio of ethyl acetate extract was 72.5%, while the proliferation inhibition ratio of ethyl acetate extract was 25.3%; as for petroleum ether extracts, the H1N1 inhibition ratio was 60.2%, while the proliferation inhibition ratio was 81.4%. In conclusion, both ethyl acetate extract and petroleum ether extract of L. pterodonta have significant neutralization and direct proliferation inhibition effects on influenza A virus.

Historical development and future perspectives of Environmental Specimen Bank in China: a mini review.

Environmental problems as well as their related ecosystem stress and human health risk in China have raised wide concerns along with the rapid economic development in recent years. Numerous studies with a sharp increase in publication number have addressed the ubiquitous of anthropogenic chemicals in various environmental compartments and human tissues. However, very few data were available to clarify the temporal trend and to give the retrospective analysis of chemical pollution in China. Environmental Specimen Bank (ESB) is a system for the systematic collection and long-term storage of specimens, which has been established since the 1970s in developed counties and recognized as a fundamental complement for environmental monitoring and scientific research. Currently, the value of ESB is becoming more broadly recognized globally, and China is still at the early stage. This article described the history and status and put forwarded the future key points of Chinese ESB development for illustrating the intensive environmental changes in China and the world.

[Linking optical properties of dissolved organic matter with NDMA formation potential in the Huangpu River].

Surface water samples from the Huangpu River were filtered to measure the UV absorption and fluorescence spectrum. Dissolved organic carbon (DOC), N-nitrosodimethylamine (NDMA), and its formation potential (NDMA-FP) were also analyzed to explore relationships between the properties of dissolved organic matter (DOM) and the formation potential of disinfection byproducts-NDMA in the Huangpu River. The study found that: NDMA-FP concentration increased with the increasing of DOC concentration (r = 0.487, P < 0.01), but it had negative relationships with SUVA254 and HIX (r = -0.605, P < 0.01; r = -0.396, P < 0.01). NDMA-FP concentration had positive relationships with the fluorescence intensity of protein-like substances such as low-molecular-weight (LMW) tyrosine-like and tryptophan-like substances (r = 0.421, P < 0.01; r = 0.426, P < 0.01), but had a negative relationship with humic-like substance (r = -0.422, P < 0.01). Therefore, NDMA formation potential increases with the increasing DOM content in the Huangpu River, which is significantly related with the protein-like substances, but decreases with the increasing aromaticity and humification of DOM.

Effects of dissolved organic matter from a eutrophic lake on the freely dissolved concentrations of emerging organic contaminants.

The authors studied the effects of dissolved organic matter (DOM) on the bioavailability of bisphenol A (BPA) and chloramphenicol by measuring the freely dissolved concentrations of the contaminants in solutions containing DOM that had been isolated from a mesocosm in a eutrophic lake. The abundance and aromaticity of the chromophoric DOM increased over the 25-d mesocosm experiment. The BPA freely dissolved concentration was 72.3% lower and the chloramphenicol freely dissolved concentration was 56.2% lower using DOM collected on day 25 than using DOM collected on day 1 of the mesocosm experiment. The freely dissolved concentrations negatively correlated with the ultraviolent absorption coefficient at 254 nm and positively correlated with the spectral slope of chromophoric DOM, suggesting that the bioavailability of these emerging organic contaminants depends on the characteristics of the DOM present. The DOM-water partition coefficients (log KOC ) for the emerging organic contaminants positively correlated with the aromaticity of the DOM, measured as humic acid-like fluorescent components C1 (excitation/emission=250[313]/412 nm) and C2 (excitation/emission=268[379]/456 nm). The authors conclude that the bioavailability of emerging organic contaminants in eutrophic lakes can be affected by changes in the DOM.

[Microbial bioavailability of dissolved nucleic acids across the estuarine salinity gradient].

As an important component of dissolved organic matter (DOM), nucleic acids (DNA and RNA) are essential nutrient and energy sources in aquatic microbial food web. Therefore, it is important to understand the bioavailability of nucleic acids. The bioavailability of nucleic acids was investigated by a batch of incubation experiments, adding fish DNA and yeast RNA into water samples with different salinity collected from the Yangtze River estuary in the spring of 2012. According to the results, 20%-50% of dissolved DNA was transformed into particulate DNA quickly with the conversion rates increasing with salinity, only 10% dissolved RNA was transformed into particulate RNA and the salinity had no effect on the conversation rates. In each incubation experiment, the microbial utilization kinetic curves of dissolved nucleic acids were fitted to the Sigmoid model. There were lag periods of 30-80 hours followed by the rapid utilization phase and then the stagnation phase. The results also showed that the bacteria in seawater had higher maximum utilization rate than the bacteria in estuarine and fresh water. Dissolved nucleic acids spiked in estuarine water can be bound to colloids and particles at some extent, only those free dissolved or enzymatically hydrolysable forms are bioavailable. The percentage of bioavailable RNA (80%-90%) was significantly higher than that of bioavailable DNA and it did not change significantly with salinity while the percent of bioavailable DNA decreased from 78% to 50% with salinity. Therefore, the speciation and bioavailability are significantly different between DNA and RNA across the estuarine salinity gradient.

[Spectral characteristics variations of chromophoric dissolved organic matter during growth of filamentous green macroalgae].

As an important component of dissolved organic matter (DOM), chromophoric dissolved organic matter (CDOM) plays a central role in the global biogeochemical carbon cycle. Macroalgae are essential producers in aquatic ecosystems. They can release a considerable part of photosynthetic products as CDOM. So changes in optical properties of CDOM are studied on filamentous green macroalgae-Chadophorasle found in tidal flats of a brackish Lake Beihu in natural field condition by using spectrometry. Humic-like fluorescence peaks and protein-like fluorescence peaks detected by fluorescence excitation-emission matrix spectrum (EEMS) change little in control experiment but increase dramatically in incubation experiment. Applying parallel factor analysis (PARAFAC) together with fluorescence excitation-emission matrix can get four components of CDOM (C1, C2, C3 and C4) which are relative to humic-like fluorescence peak A(C), M and protein-like fluorescence peak B, T respectively. In incubation experiment four components increase by 211.5%, 255.8%, 75.3% and 129.3% respectively while in control experiment components have little changes except C1 decreasing by 34.3%. Absorption coefficient alpha (355) increases by 92.9% and has positive significant correlation (P < 0.01) with the four components in incubation-experiment while alpha (355) decreases by 59.8% and only has correlation (P < 0.05) with C1 in control experiment. As the parameters representing CDOM molecular weight and composition, M and S values in incubation experiment are smaller than in control experiment, which illustrate that aromatic and macromolecular CDOM is produced in growth of Chadophorasle. All results indicate that growth of Chadophorasle can change the content and composition of CDOM.

[Distribution of phosphorus species in the sediment from Weishanhu district in Lake Nansihu].

In order to learn the phosphorus (P) species distribution in sediments of Lake Nansihu, 0-25 cm sediments from Weishanhu district in Lake Nansihu were analyzed with a sequential extraction method. The results show that: the average values of Ex-P, Al-P, Fe-P, Oc-P, Ca-P, De-P, Org-P in Weishanhu district sediments are 5.62 mg/kg, 4.08 mg/kg, 12.25 mg/kg, 13.34 mg/kg, 116.67 mg/kg, 232.36 mg/kg and 396.79 mg/kg respectively, and the rank order of P-fractionation for Lake Nansihu is Al-P < Ex-P < Fe-P < Oc-P < Ca-P < De-P < Org-P. The vertical phosphorous species distribution exhibits the obvious rule that exchangeable P (Ex-P), Fe-bound P (Fe-P), occluded P (Oc-P), organic P (Org-P) value decrease with depth, while the values of Al-bound P (Al-P), authigenic calcium bound P (A Ca-P), detrital apatite P (De-P) increase. The Sum1 content (the sum of Ex-P, Al-P and Fe-P) in surficial sediments is remarkably positively correlated with the PO4(3-) concentration of overlaying water, to which Fe-P content contributes the most with the correlation index 0.72. In spatial phosphorous species distribution, the discrepancy of potential active species(Ex-P, Al-P and Fe-P) is greater than those inert ones (Oc-P, Ca-P and De-P), and Org-P is only second to those potential active species.

Source apportionment of polycyclic aromatic hydrocarbons (PAHs) in surface sediments of the Huangpu River, Shanghai, China.

We applied cluster analysis and principal component analysis (PCA) with multivariate linear regression (MLR) to apportion sources of polycyclic aromatic hydrocarbons (PAHs) in surface sediments of the Huangpu River in Shanghai, China, based on the measured PAH concentrations of 32 samples collected at eight sites in four seasons in 2006. The results indicate that petrogenic and pyrogenic sources are the important sources of PAHs. Further analysis shows that the contributions of coal combustion, traffic-related pollution and spills of oil products (petrogenic) are 40%, 36% and 24% using PCA/MLR, respectively. Pyrogenic sources (coal combustion and traffic related pollution) contribute 76% of anthropogenic PAHs to sediments, which indicates that energy consumption is a predominant factor of PAH pollution in Shanghai. Rainfall, the monsoon and temperature play important roles in the distinct seasonal variation of PAH pollution, such that the contamination level of PAHs in spring is significantly higher than in the other seasons. BRIEF: We apportion PAHs in surface sediments of the Huangpu River and show that coal combustion, traffic-related pollution, and petroleum spillage are the major sources.

[Arsenic speciation and bioavailability in the Yangtze estuary in spring, 2006].

Field work was conducted in the Yangtze (Changjiang River) estuary in April, 2006. Water and surface sediment samples were collected to analyze total arsenic and different arsenic species, and to assess the bioavailability. Water samples were filtered through 0.45 microm filter membrane to determine the concentrations of dissolved arsenic, while the unfiltered water samples were digested by acid to determine the concentrations of total arsenic, and the difference between them was the concentrations of particulate arsenic. It is showed that the concentrations of total arsenic varied from 0.88 microg x L(-1) to 1.35 microg x L(-) at the slack of flood tide, and from 2.37 microg x L(-1) to 3.35 microg x L(-1) at the slack of ebb tide in water column of the Qingcaosha waters in the Yangtze estuary. The concentrations of both dissolved and particulate arsenic varied with the tide time. The concentrations of arsenic species at the slack of ebb tide were higher than those at the slack of flood tide, so did the percentage of particulate arsenic accounting for total arsenic. Phosphoric acid of 0.3 mol x L(-1) can effectively extract arsenate, arsenite, monomethylarsenate (MMA) and dimethylarsenite (DMA) from the sediments with the aid of microwave. The arsenic species in the extracts were detected by the hyphenated method of High Performance Liquid Chromatography-Hydrogenation-Atom Absorption Spectrometry (HPLC-HGAAS). The concentrations of total arsenic in surface sediments varied between 6.3 mg x kg(-1) and 30.7 mg x kg(-1), which were mainly contributed by inorganic arsenic species. Arsenate was dominated in the sediments in the offshore waters while arsenite was dominated in the sediments in longshore waters. The concentrations of available arsenic in the sediments, which were estimated by the method of acetate cellulose composite membrane embedded with iron oxides (FeO/CAM), accounted for 0.6% to 3.9% (averaged as 2.1%) of the total arsenic concentrations. The available arsenic concentrations had no significant correlation with the total arsenic concentrations, but had significant positive correlation with the arsenate concentrations and had significant negative correlation with the arsenite concentrations. The results also showed that the distribution of arsenic species in the sediments and their bioavailability in the South Branch of the Yangtze estuary were significantly influenced by the tributary river flows and effluents from the urban area.

[New method to assess phosphorus bioavailability in the sediments and soils].

A new method to assess phosphorus bioavailability in the sediments and soils was developed by using a homemade iron oxide/ cellulose acetate membrane(FeO/CAM). The results show that the amount of bioavailable phosphorus(FeO-P) desorbed from the sediment and soil increased with the shaking time,and FeO-P desorption would come to equilibrium after 16 ot 20h. With the increase of the ratio between soil mass and water volume, the quantity of the desorbed FeO-P would decrease and then went planar after 20 to 30g/L. The quantity of the desorbed FeO-P had no significant difference between the FeO/CAMs of 20 to 30cm2. The dynamics of FeO-P desorption from the sediments and soils would be accelerated by appropriately increasing the shaking frequency. In short, FeO/ CAMs overcome many disadvantages of iron oxide impregnated filter paper and are easy to be commercialized; therefore it may have a better future in the application to assessing phosphorus hioavailability in the sediments and soils.

Origins and mobility of phosphorus forms in the sediments of Lakes Taihu and Chaohu, China.

Phosphorus release from the sediment is generally an important factor for lake eutrophication. We have investigated phosphorus forms in surface sediments from Lake Taihu and Lake Chaohu by a chemical extraction method. The results showed that the concentrations of Fe/Al-bound phosphorus (Fe/Al-P) and organic phosphorus (Org-P) had significant correlations with those of amorphous Fe/Al oxides and organic matter in the sediments. Furthermore, Ca-bound phosphorus (Ca-P) concentrations were well related to total organic carbon (TOC) concentrations. The results also indicated that higher pH weakened the association of phosphates with the Fe/Al hydroxides and then resulted in Fe/Al-P release. The increase of pH was companied with autogenetic progresses of calcium carbonate and then elevated Ca-P concentrations in the sediments. In conclusion, external P loadings determine spatial distribution of P fractions, especially Fe/Al-P and Org-P, and partially contribute to additional Ca-P fractions in these highly human-disturbed lakes. The pH-induced phosphorus mobility in the sediments is very important for these lakes.