Biomedical subjects

Shu Tao

Publications and source records attributed to Shu Tao.

At least 37 records · Page 2Linked to original sources

PubMed2005

Distribution and characteristics of organic micropollutants in surface sediments from Bohai Sea.

Spatial distribution and compositional characteristics of PAHs, DDTs and PCBs in surface sediments from Bohai Sea were investigated. Proportion of LMW PAHs at Jinzhou Bay was significant, due probably to the petrogenic sources from neighboring oil wells and plants, while HMW PAHs were dominant in the other sea areas, inferred pyrogenic origins mainly from coal or petroleum combustion. The average ERL quotient for the PAH species in Qinhuangdao and Liaodong Bay indicated relatively stronger potential ecological risk. The concentration ratios of DDT to metabolites (DDD + DDE) exceeded 1.0 in the coastal areas of Qinhuangdao, Liaodong Bay and Bohai Bay, demonstrated some recent inputs of DDT nearby, and DDD as the major degradation product. The concentrations of PCBs were generally low, however, the contents of DDTs were greater than the ERL guidelines in the coastal areas of Qinhuangdao, Liaodong Bay and Bohai Bay, and suggested the potential ecological risk.

Chromatography, Gas↗

PubMed2005

Trophodynamic behavior of 4-nonylphenol and nonylphenol polyethoxylate in a marine aquatic food web from Bohai Bay, north China: comparison to DDTs.

4-Nonylphenol (4-NP) is of particular concern because of its ubiquity in aquatic environment and its endocrine-disrupting effects in aquatic organisms. On the basis of its octanol-water partition coefficient (104.6), it has a potential to bioaccumulate in aquatic food webs. However, there are no reported field studies on the trophodynamics of 4-NP and its precursor, nonylphenol polyethoxylate (NPEOs) surfactants, in aquatic food webs. This study reports the trophodynamics of 4-NP and NPEOs (4 < s < 16) in a marine aquatic food web from Bohai Bay, North China. 4-NP and NPEOs (4 < s < 16) were determined in 14 marine species including plankton, benthic invertebrates, fish, and marine birds. This paper provides the first report on the occurrence of NPEOs with s > 5 in marine biota. Co-analysis of DDTs in all samples allowed a direct comparison of the bioaccumulation behavior of DDTs with that of NP and NPEOs. The lipid equivalent concentration of DDE and 2,2-bis(chlorophenyl)-1-chloroethylene (DDMU) increased with increasing trophic level, and the trophic level was determined by stable isotope ratios. The trophic magnification factors (TMFs) of DDE and DDMU were 3.26 and 3.7, respectively. Lipid equivalent concentrations of 4-NP and of all NPEOs did not exhibit a statistically significant correlation with trophic levels in the food web, and the TMF of NP was 0.83, which was similar to those of all NPEOs (0.45-1.22). These results show that in the studied aquatic food web, there was no trophic magnification for 4-NP and NPEOs, whereas DDE and DDMU biomagnified.

Animals↗

PubMed2005

Synchronous-scan fluorescence spectra of Chlorella vulgaris solution.

The characterization of the Chlorella vulgaris solution was carried out using synchronous-scan spectroscopy. The range of concentration of algae and Fe(III) in aqueous solutions were 5 x 10(8)-8 x 10(9) cells l(-1) and 10-60 microM, respectively. Effective characterization method used was synchronous-scan fluorescence spectroscopy. The wavelength difference (Deltalambda) of 90 nm was maintained between excitation and emission wavelengths; 90 nm was found to be the best Deltalambda for effective characterization of Chlorella vulgaris solution with or without quencher species (e.g., Fe(III), humic acid (HA)) for the first time. The peak was observed at about EX 236.6 nm/EM 326.6 nm for synchronous-scan fluorescence spectra. The fluorescence quenching of algae in system of algae-Fe(III)-HA was studied using synchronous-scan spectroscopy for the first time. Fe(III) was clearly the effective quencher. The relationship between I0/I (quenching efficiency) and c (concentration of Fe(III) added) was a linear correlation for the algae solution with Fe(III). Also, Aldrich humic acid was found to be an effective quencher. pH effect on synchronous-scan fluorescence intensity of algal solution with Fe(III) and/or HA was evident.

Chlorella vulgaris↗

PubMed2005

Nonylphenol and nonylphenol ethoxylates in river water, drinking water,and fish tissues in the area of Chongqing, China.

Little attention has been paid to the estrogenic-like compounds, such as 4-nonylphenol (4-NP) and its potential precursor nonylphenol ethoxylates (NPEOs), in China although its usage is huge. Water samples and corresponding drinking water samples were seasonally collected at five sites of each of the two main rivers in Chongqing Area. Individual nonylphenol ethoxylates (NPEOs) and 4-NP in the Changjiang River and Jialingjiang River were detected by normal-phase liquid chromatography electrospray ionization mass spectrometry and gas chromatography-mass spectrometry. The results indicated that of the five sampling points in the two rivers, NPEOs were the dominant pollutant in April and December with the similar distribution profile, and total NPEOs with different ethylene oxide lengths were 6.9-97.6 microg/L in April and 2.5-52.7 microg/L in December. However, NP was the dominant pollutant in July with a concentration of 1.7-7.3 microg/L. Corresponding drinking water samples derived from river water as source suggested that the conventional water treatment process used in the five waterworks could remove NPEOs from the source water with high removal efficiency (>99%). The 4-NP removal efficiency, however, varied in a range of 62% to 95%, leaving a significantly high concentration of NP (0.1 to 2.7 microg/L) in drinking water in July. Fish samples taken in December 2000 contained 4-NP of approximately 1.9 microg/g and NPEOs of 0.4-48.3 microg/g, with the highest concentration level found in liver.

Animals↗

PubMed2005

The 7-decade degradation of a large freshwater lake in central Yangtze River, China.

Freshwater lakes store water for human use and agricultural irrigation and provide habitats for aquatic fauna and flora. However, a number of these lakes have been degraded by human activities at a rapid rate. Here, we used historical land cover information and remotely sensed data to explore a 7-decade (between 1930s and 1998) shrinkage and fragmentation of Dongting Lake, the second largest freshwater lake in China, located in the drainage basin of Central Yangtze River. The water surface area of Dongting Lake decreased by 49.2%, from 4955 km2 in the 1930s to 2518 km2 in 1998, with an average decrease rate of 38.1 km2/yr in the past 7 decades. The lake was also fragmented, as indicated by a decreasing mean patch size from 4.2 km2 in the 1930s to 1.7 km2 in 1998. The degradation of the lake is largely attributed to a rapidly growing human population in the lake region that led to extensive impoldering. The degradation of the lake has resulted in negative ecological consequences, such as frequent flooding, a decline of biodiversity, and extinction of some endemic species. Our results also suggest that lake restoration projects implemented in this region since the end of the 1990s will help to decrease the lake degradation.

Animals↗

PubMed2005

Hexachlorocyclohexane and dichlorodiphenyltrichloroethane residues in the dustfall of Tianjin, China.

Heating and nonheating season dustfall samples were collected from 23 sites in Tianjin, China during 2002-2003 to determine residues of hexachlorocyclohexane isomers (a-HCH, beta-HCH, gamma-HCH, and beta-HCH) and dichlorodiphenyltrichloroethane and metabolites (p,p'-DDE, p,p'-DDD, and p,p'-DDT). Concentrations of sumHCH (sum of alpha-, beta-, gamma-, and delta-HCH) and sumDDT (sum of p,p'-DDE, p,p'-DDD, and p,p'-DDT) varied in ranges of 10.9-3.16 x 10(3) and 37.9-1.53 x 10(3) ng g(-1) dry weight in heating season and in ranges of 6.9-1.12 x 10(3) and 18.6-626 ng g(-1) dry weight in nonheating season, respectively. It was found that HCHs and DDTs concentrations of the most heating season samples were higher than those of nonheating season samples collected from the same sites. Among studied compounds of the HCH family, beta-HCH prevailed in most samples, suggesting a possible volatilization or resuspension from contaminated topsoil. As for DDTs, p,p'-DDT and p,p'-DDE prevailed in most samples, indicating a possible "fresh" input. Correlations between HCHs/DDTs and total organic carbon and particle size are discussed. Atmospheric deposition fluxes were calculated for the heating and nonheating seasons, and the results showed that the annual input of particulate sumHCH and sumDDT from air to surface in the studied area of 1.19 x 10(4) km2 were 89 t and 80 t, respectively.

Air↗

PubMed2005

Induction of vitellogenin mRNA in juvenile Chinese sturgeon (Acipenser sinensis Gray) treated with 17beta-estradiol and 4-nonylphenol.

It has been demonstrated that 4-nonylphenol (4-NP) exerts estrogenic effects in diverse fishes. The present study investigated the effects of 4-NP on Chinese sturgeon (Acipenser sinensis Gray) vitellogenin (VTG) gene expression. By reverse transcription-polymerase chain reaction (RT-PCR) using degenerate primers, a 462-base pair fragment of Chinese sturgeon VTG, corresponding to a 154-amino acid sequence, was amplified and sequenced. This sequence exhibited 152/154 identity to the amino acid sequence of white sturgeon (A. transmontano) VTG. Conventional RT-PCR and quantitative real-time RT-PCR were established and used to study the VTG and beta-actin gene expression in the liver of juvenile Chinese sturgeon injected three times with 17beta-estradiol (5 mg/kg body wt/week) or 4-NP (10 or 100 mg/kg/week) in the course of three weeks. Significant induction of VTG gene expression was detected in all treated groups, and no VTG mRNA was detected in the control group. The ratio of VTG to beta-actin analyzed from the results of quantitative real-time RT-PCR reached 0.041 +/- 0.024 (mean +/- SD) in the group receiving 10 mg/kg/week of 4-NP and 4.51 +/- 1.68 in the group receiving 100 mg/kg/week of 4-NP. Chemical analysis of 4-NP showed that the concentrations of 4-NP in the 10 mg/kg/week group and the 100 mg/kg/week group were 2.78 +/- 2.41 and 31.38 +/- 0.26 mcirog/ g wet weight, respectively. Compared with the 4-NP concentrations (0.8-1.92 microg/g wet wt) in fish from the Yangtze River, China, a potential hazard exists regarding 4-NP in Chinese sturgeon. These results represent the first indication of the risk of endocrine-disrupting chemicals for Chinese sturgeon.

Actins↗

PubMed2005

[Multi-scale spatial relations of PAHs and soil properties in Tianjin area].

Polycyclic aromatic hydrocarbons(PAHs) in soil have serious latent danger to our human health. Based on the sampling data, the spatial scale-dependent correlations of PAHs content and some soil properties are analyzed by Factorial Kriging for top soil in Tianjin area. Based on 1 88 topsoil samples in Tianjin area, pH, TOC, CLAY and sum of 16prior PAHs are tested. Resultsshow that significant difference on spatial correlations at different spatial scales between the PAHs content and soil properties such as pH, TOC and CLAY existed in the studies area.

China↗

PubMed2005

[Population exposure to HCH in Tianjin area].

The population exposure to HCH in Tianjin area is estimated based on field data on media concentration and other data from the literature. A multimedia /multipathway human exposure model is employed to calculate the population' s Chronic Daily Intake (CDI) of HCH. The population's lifetime CDI was 0.05microg x (kg x d)-1, and the daily exposures of child, youth and adult were 0.10, 0.06, and 0.04microg x (kg x d)-1, respectively. The result indicates that diet exposure was the most important route, accounting for 87% of total dose. Respiration ranked second and contributed 5% - 10% of the total dose.

China↗

PubMed2005

[Loss of life expectancy analysis for cancer risk in Tianjin area].

Loss of Life Expectancy was proposed as the single metric for health risk assessment. Based on the statistical data of population in Tianjin, it was calculated that the unit cancer risk (10(-5)) equivalents to 58.47 and 66.82 minutes of life expectancy loss for male and female, respectively. The results depend strongly on the background rate of cancer, with little response for associated parameters.

China↗

PubMed2005

[Influences of surfactant on the transport of PAHs in artificially contaminated soil columns].

The effect of anionic surfactant LAS on leaching of PAHs from artificially contaminated soil was studied. The interaction of these processes were studied in a two-layer column experiment with a base layer of uncontaminated soil(9cm) and a top layer of artificially contaminated soil(1cm). Results show that 5 critical micelle concentration (CMC) LAS enhanced the transport of PAHs. The breakthrough curves of low ring PAHs followed the normal distribution and the relative leaching ratios of 4 or more rings PAHs were low, and not more than 10%. The transport of PAHs was retarded compared with LAS, and the high ring PAHs were retarded more significantly. Linear correlation was observed between the relative leachability of the individual PAHs and the octanol/water coefficient of PAHs.

Polycyclic Aromatic Hydrocarbons↗

PubMed2005

[Influence of water soluble organic carbon on determination of adsorption coefficient of phenanthrene].

Organic carbon normalized sorption coefficient of phenanthrene in soils was determined in a batch experiment. The influence of the presence of dissolved organic carbon (DOC) on sorption coefficient was also investigated. The results demonstrated that, the DOC dissolved from the soil would enhance the water solubility of phenanthrene and change the sorption behavior of phenanthrene between soil and water, consequently leading to an underestimation of sorption coefficient. When the binding coefficient of DOC and phenanthrene (K(doc)) from the literatures was adopted for correction of measured data, a better estimation of sorption coefficient could be achieved. In this study, lgK(oc) and lgK(Foc) were 4.35 and 7.01, respectively. Comparison between the uncorrected/corrected lgK(oc) and the literature data could partially reflect the deviation caused by the influence from various concentrations of DOC may occur in many sorption studies in water-soil system. It was significant to compare the sorption coefficient derived from different studies considering this influence.

Adsorption↗

PubMed2005

Thermodynamics of phenanthrene partition into solid organic matter from water.

The thermodynamic behavior of organic contaminants in soils is essential to develop remediation technologies and assess risk from alternative technologies. Thermodynamics of phenanthrene partition into four solids(three soils and a bentonite) from water were investigated. The thermodynamics parameters (deltaH, deltaG degrees, deltaS degrees) were calculated according to experimental data. The total sorption heats of phenanthrene to solids from water ranged from -7.93 to -17.1 kJ/mol, which were less exothermic than the condensation heat of phenanthrene-solid (i.e., -18.6 kJ/mol). The partition heats of phenanthrene dissolved into solid organic matter ranged from 23.1 to 32.2 kJ/mol, which were less endothermic than the aqueous dissolved heat of phenanthrene (i.e., 40.2 kJ/mol), and were more endothermic than the fusion heat of phenanthrene-solid (i.e., 18.6 kJ/mol). The standard free energy changes, deltaG degrees, are all negative which suggested that phenanthrene sorption into solid was a spontaneous process. The positive values of standard entropy changes, deltaS degrees, show a gain in entropy for the transfer of phenanthrene at the stated standard state. Due to solubility-enhancement of phenanthrene, the partition coefficients normalized by organic carbon contents decrease with increasing system temperature (i.e., ln Koc = -0.284 ln S + 9.82 (n = 4, r2 = 0.992)). The solubility of phenanthrene in solid organic matter increased with increasing temperatures. Transports of phenanthrene in different latitude locations and seasons would be predicted according to its sorption thermodynamics behavior.

Adsorption↗

PubMed2005

The role of arbuscular mycorrhiza on change of heavy metal speciation in rhizosphere of maize in wastewater irrigated agriculture soil.

To understand the roles of mycorrhiza in metal speciation in the rhizosphere and the impact on increasing host plant tolerance against excessive heavy metals in soil, maize (Zea mays L.) inoculated with arbuscular mycorrhizal fungus (Glomus mosseae) was cultivated in heavy metal contaminated soil. Speciations of copper, zinc and lead in the soil were analyzed with the technique of sequential extraction. The results showed that, in comparison to the bolked soil, the exchangeable copper increased from 26% to 43% in non-infected and AM-infected rhizoshpere respectively; while other speciation (organic, carbonate and Fe-Mn oxide copper) remained constant and the organic bound zinc and lead also increased but the exchangeable zinc and lead were undetectable. The organic bound copper, zinc and lead were higher by 15%, 40% and 20%, respectively, in the rhizosphere of arbuscular mycorrhiza infected maize in comparison to the non-infected maize. The results might indicate that mycorrhiza could protect its host plants from the phytotoxicity of excessive copper, zinc and lead by changing the speciation from bio-available to the non-bio-available form. The fact that copper and zinc accumulation in the roots and shoots of mycorrhia infected plants were significantly lower than those in the non-infected plants might also suggest that mycorrhiza efficiently restricted excessive copper and zinc absorptions into the host plants. Compared to the non-infected seedlings, the lead content of infected seedlings was 60% higher in shoots. This might illustrate that mycorrhiza have a different mechanism for protecting its host from excessive lead phytotoxicity by chelating lead in the shoots.

Analysis of Variance↗

PubMed2004

Multimedia fate model for hexachlorocyclohexane in Tianjin, China.

A level III fugacity model was applied to characterize the fate of gamma-HCH in Tianjin, China, before the 1990s when the contamination reached its maximum at steady state. Geometric means were used as model inputs. The concentrations of gamma-HCH in air, surface water, soil, sediment, crops, and fish as well as transfer fluxes across the interface between the compartments were derived under the assumption of steady state. The calculated concentrations were validated by independent data collected from the literature. There was generally good agreement between the estimated and the observed concentrations, and the differences were all less than 0.6 log units for air, water, soil, sediment, and fish and approximately 1 order of magnitude for crops. Around 97% of gamma-HCH accumulated in soil and sediment. Wastewater irrigation was not an important pathway for delivering gamma-HCH to soil as compared to the dominant source of agricultural application. Degradation and advective airflow carried much gamma-HCH out of the system. Sensitivities of the model estimates to input parameters were tested, and a coefficient of variation normalized sensitivity coefficient was defined for the test. The most influential parameters were degradation rates in sediment and soil, application rates, concentrations in wastewater, and adsorption coefficients. Monte Carlo simulation was conducted for model uncertainty analysis. The model was run 20 000 times using randomly generated data from predefined log-normal distribution density functions. All calculated concentrations and fluxes were log-normally distributed. The dispersions of the calculated and observed concentrations were compared in terms of coefficients of variation to distinguish between true variability and model uncertainty.

Air↗

PubMed2004

Long-term temporal-spatial dynamics of marine coastal water quality in the Tolo Harbor, Hong Kong, China.

The long-term temporal and spatial dynamics of marine coastal water quality in Tolo Harbor, Hong Kong were explored. The Harbor is divided into three zones represented as Harbor, Buffer, and Channel Subzones. The time range for the study covers the period from the 1970s to the 1990s. The selected indicators for the comprehensive assessment of water quality consist of physical, chemical and biological aspects, including suspended solids(SS), Secchi disk depth(SD), 5-day biochemical oxygen demand(BOD5), total nitrogen (TN), total phosphorus(TP), faecal coliform, chlorophyll-a(Chl-a), and the number of red tide occurrences. The results indicated the presence of obvious temporal and spatial trends with regard to changes in water quality. Spatially, water quality in the Channel Subzone is the best, while that in the Harbor Subzone is the worst. On a temporal basis, the average trend from bad to good was 1980s > 1990s > 1970s as indicated by most of the selected water quality indicators. Water quality during the late 1980s reached its worst level with the lowest SD, the highest BOD5, TN, TP, Chl-a concentrations, and the number of red tide occurrences. These long-term temporal-spatial water quality trends were also found in other studies of the Tolo Harbor. The large quantity of pollutants produced as a result of increasing population, industrial and commercial actives, and urbanization and industrialization trends in both Shatin and Tai Po seem to be primarily responsible for the changes in marine coastal water quality.

Commerce↗

PubMed2004

[Risk analysis of naphthalene pollution in soils of Tianjin].

Three approaches were applied and evaluated for probabilistic risk assessment of naphthalene in soils of Tianjin, China, based on the observed naphthalene concentration of 188 top soil samples from the area and LC50 of naphthalene to ten typical soil fauna species from the literature. It was found that the overlapping area of the two probability density functions of concentration and LC50 was 6.4%, the joint probability curve bend towards and very close to the bottom and left axis, and the calculated probability that exposure concentration exceeds LC50 of various species was as low as 1.67%, all indicating a very much acceptable risk of naphthalene to the soil fauna ecosystem and only some of very sensitive species or individual animals are threaten by localized extremely high concentration. The three approaches revealed similar results from different viewpoints.

Animals↗

PubMed2004

[PAHs in foliar dust from Beijing urban area].

A five-step sequential elution procedure with or without supersonic effect was tested for extraction of foliar dust from leaves of Euonymus japonicus collected at two locations of Beijing urban area. The samples were collected from either roadside or campus far away from any motor traffic. The foliar dust was characterized for size distribution, organic carbon content, and PAHs content. It was found that majority of the foliar dust can be eluted in 4 min by distill water under supersonic effect at room temperature without shaking. The amount of foliar dust on the sample from roadside was almost twice as much as those from campus, while the particle size of the former was relatively large. Large amount of coarse particles came from disturbance of motor vehicles. Slightly high concentrations of PAH species were detected in the sample from campus compared to those in the samples collected from roadside.

Cities↗