共查询到20条相似文献,搜索用时 15 毫秒
1.
Xueying Wang Libin Wu Jing Sun Yangyang Wei Yongli Zhou Zixuan Rao Linxi Yuan Xiaodong Liu 《Bulletin of environmental contamination and toxicology》2018,101(1):42-48
We measured total mercury (Hg) and selenium (Se) concentrations as well as stable nitrogen (N) isotopic composition in flyingfish and squid muscle tissues from the eastern Indian Ocean and western South China Sea. The results showed that the mean Hg concentration in squid muscle from the western South China Sea was lower than that in the eastern Indian Ocean. The Hg concentrations in flyingfish and squid muscle samples were positively correlated with organism size (length and weight) and δ15N in all the study areas. Furthermore, we found a negative correlation between Se and Hg in molar content of flyingfish and squid muscle from the western South China Sea. The Se:Hg molar ratio was significantly negative correlated with fish weight and δ15N, suggesting that the Se:Hg molar ratio decreases with the increase of fish size and trophic level in the food web. 相似文献
2.
Chirality in pesticides has become a challenge because of enantiomers’ different toxicities to non-target organisms. Acute
and chronic toxicities of Rac-metalaxyl and R-metalaxyl to Daphnia magna were determined and compared. The 48-h LC50 for Rac- and R-metalaxyl to Daphnia magna were 51.5 and 41.9 mg/L. In a 14-day chronic test, the lowest-observed-effective concentration (LOEC) and no-observed-effective
concentration (NOEC) of Rac-metalaxyl were 2 and 1 mg/L, respectively, whereas those of R-metalaxyl were 1 and 0.1 mg/L. Body length, days-to-first-brood and number of broods per female were significantly (p < 0.05) affected by R-metalaxyl at >1.0 mg/L, but affected by Rac-metalaxyl at ≥2.0 mg/L. 相似文献
3.
In the present study, the growth of Chrysanthemum coronarium L. and Sorghum sudanense L. and their copper accumulation were studied using hydroponic experiments. Results showed that the root elongation, dry
biomass yield, and chlorophyll content in both plant species decreased significantly with the increasing level of Cu in solution.
The concentrations of Cu in the two plants increased greatly with the increasing Cu level in the treatments. However, most
of the Cu was accumulated in roots, and only a small portion was translocated into shoots. Compared with S. sudanense, the shoots of C. coronarium had a significantly higher concentration of Cu. The total amount and percentage of water-soluble Cu, and the nonprotein thiol
were also higher in the shoots of C. coronarium. In the roots, however, S. sudanense accumulated more Cu than C. coronarium. The treatments with 5 to 50 μmol L−1 Cu significantly increased the uronic acid content in the roots of S. sudanens, but did not have any significant effect for C. coronarium. Higher concentrations of Cu bound to the cell wall and uronic acid in the roots of S. sudanense were speculated to be the main reason to restrain Cu translocation from roots to shoots. 相似文献
4.
Song ZH 《Bulletin of environmental contamination and toxicology》2007,79(3):278-282
The 24-h median lethal concentrations of pentachlorophenol to Chironomus
plumousus, Tubifex sinicus and Galba pervia were 0.302, 0.977 and 0.293 mg/L, respectively. Bioconcentration factors of C. plumousus, T. sinicus and G. pervia to pentachlorophenol were 108, 367 and 85 at 0.02 mg/L pentachlorophenol, respectively. As pentachlorophenol concentration
increased, the G. pervia egg hatching rates became lower, and the total hatched time became longer. Pentachlorophenol teratogenesis was demonstrated
by observing the deformation of C. plumousus larvae mentum. 相似文献
5.
Rezayi M Esmaeli AS Valinasab T 《Bulletin of environmental contamination and toxicology》2011,86(5):511-514
In this paper the level of selenium and mercury is analyzed in edible part and liver of Psettodes erumei and Otolithes ruber two commercial fish in Persian Gulf. The average concentration of Hg and Se in edible parts of P. erumei was 0.077 ± 0.062 and 0.044 ± 0.018 (μg g−1ww), and in liver was 0.127 ± 0.122 and 0.132 ± 0.610 (μg g−1ww) respectively. In O. ruber, the average concentration of Hg and Se in edible parts was 0.348–0.27 and 0.06 ± 0.021 (μg g−1ww) and in liver was 0.176 ± 0.174 and 0.093 ± 0.022 (μg g−1ww), respectively. P. erumei has higher mean molar ratio Se/Hg (1.98) compared to O. ruber (0.88). 相似文献
6.
7.
Haiping Wang Feng Liu Pei Luo Zihan Li Liguo Zheng Hua Wang Dongsheng Zou Jinshui Wu 《Bulletin of environmental contamination and toxicology》2017,98(4):556-561
Allelopathy has been proposed as a sustainable means to control undesired algal growth and to reduce blooms threatening freshwater systems worldwide. In this study, the allelopathic effects of Myriophyllum aquaticum and its exudate on two typical bloom-forming cyanobacteria, Microcystis aeruginosa and Anabaena flos-aquae, were investigated under laboratory conditions. The growth of the cyanobacteria was strongly inhibited by live M. aquaticum while the primary addition of M. Aquaticum exudates had a significant inhibitory effect on the growth of M. aeruginosa but not A. flos-aquae. The results suggested that the persistent release of allelochemicals from live M. aquaticum was needed to effectively constrain the growth of A. flos-aquae. Analysis of cyanobacterial physiological indexes indicated that M. aquaticum produced an inhibitory effect on SOD enzyme activity of A. flos-aquae, while it affected membrane lipid peroxidation in M. aeruginosa. The results show the potential of M. aquaticum to mitigate cyanobacterial blooms in coexistence systems. 相似文献
8.
Haihua Wang Lili Cui Huamin Cheng Yu Zhang Xiaoping Diao Jun Wang 《Bulletin of environmental contamination and toxicology》2017,98(5):649-655
Research on the kinetics of Benzo[a]pyrene (B[a]P) bioaccumulation in the clam Pinctada martensii and mussel Perna viridis showed that the initial rate of uptake was directly related to the PAH concentrations in the ambient environment. The uptake and depuration rate constants were different at the four B[a]P exposure levels, which indicated that the toxicokinetic rate constants mainly depended on the exposure levels of pollutants to the environment. In addition, the uptake rate constants of B[a]P were higher than the depuration rate constants in the entire experiment. The comparison demonstrated that mussels release B[a]P more rapidly than clams. The bioconcentration factors (BCFs) of B[a]P varied from 3335 to 12892 in the clam and 2373–6235 in the mussel. These findings on the bioaccumulation kinetics for petroleum hydrocarbons, in association with the critical body residue, will be valuable when choosing sensitive organisms to assess the potential ecotoxicological risk to the marine environment. 相似文献
9.
10.
11.
12.
López D Chamorro S Silva J Bay-Schmith E Vidal G 《Bulletin of environmental contamination and toxicology》2011,87(6):633-637
Two kraft pulp mill effluents were compared in terms of their chronic toxicity to Daphnia magna. One resulted from pulping Pinus radiata and the other came from a parallel processing of Pinus radiata and Eucalyptus globulus (mixed kraft pulp mill effluent). The concentration of phytosterols found in the mixed kraft pulp mill effluent was higher than in the effluent from Pinus radiata, with values of 0.1082 and 0.02 μg/L, respectively. The phytosterols per se are responsible for 12.9% and 8.1% of the deviation from the natural shape, while the kraft pulp mill effluents account for
25.6%–27.8% of shape deviation. The role of β-sitosterol and stigmasterol is discussed in relation to endocrine disruption. 相似文献
13.
Rours GI de Krijger RR Ott A Willemse HF de Groot R Zimmermann LJ Kornelisse RF Verbrugh HA Verkooijen RP 《European journal of epidemiology》2011,26(5):421-428
Chlamydia
trachomatis may infect the placenta and subsequently lead to preterm delivery. Our aim was to evaluate the relationship between the presence
of Chlamydia
trachomatis and signs of placental inflammation in women who delivered at 32 weeks gestation or less. Setting: placental histology and
clinical data were prospectively obtained from 304 women and newborns at the Erasmus MC-Sophia, Rotterdam, the Netherlands.
C.
trachomatis testing of placentas was done retrospectively using PCR. C.
trachomatis was detected in 76 (25%) placentas. Histological evidence of placental inflammation was present in 123 (40%) placentas: in
41/76 (54%) placentas with C.
trachomatis versus 82/228 (36%) placentas without C.
trachomatis infection (OR 2.1, 95% CI 1.2–3.5). C.
trachomatis infection correlated with the progression (P = 0.009) and intensity (P = 0.007) of materno-fetal placental inflammation. C.
trachomatis DNA was frequently detected in the placenta of women with early preterm delivery, and was associated with histopathological
signs of placental inflammation. 相似文献
14.
15.
Ancora S Rossi R Simplicio PD Lusini L Leonzio C 《Archives of environmental contamination and toxicology》2002,42(3):348-353
The biochemical behavior of methylmercury (MeHg) in dolphin blood was investigated in vitro. MeHg distribution between plasma and erythrocytes and its release from erythrocytes into plasma or medium without SH group
was determined. At the subcellular level its distribution among different thiol-containing molecules was also investigated
in erythrocytes and plasma. When blood was treated with 0.1 mM MeHg, about 98.1% was found in red cells and 1.9% in plasma;
only 0.6% of MeHg present in the cellular compartment was bound to membranes.
Hemoglobin (Hb) and albumin, principal proteins containing SH groups (PSH), and glutathione (GSH) appeared to be the main
targets of MeHg in dolphin blood. Gel filtration of stroma-free hemolysate of treated red blood cells (RBCs) revealed that
MeHg was almost equally present in high (52.5%) and low (47.5%) molecular weight fractions, whereas in plasma it only eluted
with proteins (high molecular weight fractions). Hemoglobin was identified as the main intracellular protein binding MeHg.
The exchange reaction of MeHg between GSH and dolphin hemoglobin was also evaluated and the equilibrium constants calculated.
Received: 14 May 2001/Accepted: 1 October 2001 相似文献
16.
17.
Yuping Ding Donald P. Weston Jing You Amanda K. Rothert Michael J. Lydy 《Archives of environmental contamination and toxicology》2011,61(1):83-92
Two hundred sediment samples were collected and their toxicity evaluated to aquatic species in a previous study in the agriculturally
dominated Central Valley of California, United States. Pyrethroid insecticides were the main contributors to the observed
toxicity. However, mortality in approximately one third of the toxic samples could not be explained solely by the presence
of pyrethroids in the matrices. Hundreds of pesticides are currently used in the Central Valley of California, but only a
few dozen are analyzed in standard environmental monitoring. A significant amount of unexplained sediment toxicity may be
due to pesticides that are in widespread use that but have not been routinely monitored in the environment, and even if some
of them were, the concentrations harmful to aquatic organisms are unknown. In this study, toxicity thresholds for nine sediment-associated
pesticides including abamectin, diazinon, dicofol, fenpropathrin, indoxacarb, methyl parathion, oxyfluorfen, propargite, and
pyraclostrobin were established for two aquatic species, the midge Chironomus dilutus and the amphipod Hyalella azteca. For midges, the median lethal concentration (LC50) of the pesticides ranged from 0.18 to 964 μg/g organic carbon (OC), with abamectin being the most toxic and propargite being
the least toxic pesticide. A sublethal growth endpoint using average individual ash-free dry mass was also measured for the
midges. The no–observable effect concentration values for growth ranged from 0.10 to 633 μg/g OC for the nine pesticides.
For the amphipods, fenpropathrin was the most toxic, with an LC50 of 1–2 μg/g OC. Abamectin, diazinon, and methyl parathion were all moderately toxic (LC50s 2.8–26 μg/g OC). Dicofol, indoxacarb, oxyfluorfen, propargite, and pyraclostrobin were all relatively nontoxic, with LC50s greater than the highest concentrations tested. The toxicity information collected in the present study will be helpful
in decreasing the frequency of unexplained sediment toxicity in agricultural waterways. 相似文献
18.
Background
Diarrhea is a major contributor to the burden of morbidity and mortality in children; it accounts for a median of 11% of all deaths among children aged less than 5 years, amounting to approximately 0.8 million deaths per year. Currently there is a dearth of literature exploring the effectiveness of antibiotics for diarrhea due to Cholera, Shigella and cryptosporidiosis in children.Methods
We reviewed the literature reporting the effect of antibiotics for the treatment of diarrhea due to Cholera, Shigella and Cryptosporidium in children under five years. We used a standardized abstraction and grading format and performed meta-analyses to determine the effect of the treatment with various antibiotics on mortality and rates of clinical and bacteriological/parasitological failure. The CHERG Standard Rules were applied to determine the final effect of treatment with antibiotics on diarrhea morbidity and mortality.Results
For Cholera; the evidence was weak to recommend any effect on mortality. For Shigella; there was no data on mortality; either all-cause or cause specific, hence we used clinical failure rates as a proxy for Shigella deaths and propose that treatment of Shigella dysentery with antibiotics can result in a 82% reduction in diarrhea mortality due to Shigella. For cryptosporidiosis; there was data on all-cause mortality but the evidence was weak hence we used clinical failure rates as a proxy for mortality to estimate that antimicrobial treatment of diarrhea due to cryptosporidiosis can result in a 54% reduction in mortality.Conclusions
There is evidence to recommend antibiotic use for reduction of morbidity and mortality due to Cholera, Shigella and Cryptosporidium. We recommend that more clinical trials should be conducted to evaluate the efficacy and safety of first- and second- line drugs currently in use for treatment for diarrhea and dysentery in both developing and developed countries.19.
Wei-Dong Yang Jie-Sheng Liu Hong-Ye Li Xin-Lian Zhang Yu-Zao Qi 《Bulletin of environmental contamination and toxicology》2009,83(4):537-541
The wood sawdust from Chinese fir (Cunninghamia lanceolata) exhibited stronger inhibition on the growth of Alexandrium tamarense than those from alder (Alnus cremastogyne), pine (Pinus massoniana), birch (Betula alnoides) and sapele (Entandrophragma cylindricum). The water extract, acetone-water extract and essential oil from fir sawdust were all shown to inhibit the growth of A. tamarense. The inhibition of fir essential oil was the strongest among all the above wood sources while the half effective concentration
was only 0.65 mg/L. These results suggested that the fir essential oil may play an important role in the algicidal effect
of Chinese fir. 相似文献