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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
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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
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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
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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
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The impacts of N,N-dimethylformamide (DMF) from domestic effluents on rivers were evaluated. The hourly DMF concentrations in the inflows (0.21–0.52 μg/L in mean) and the outflows (0.18–0.62 μg/L in mean) of two sewage treatment plants did not show any characteristic variations, and DMF was not removed at both plants. The monthly variations of DMF in the outflows of four sewage treatment plants (0.16–0.62 μg/L in mean) and three rivers (0.06–0.11 μg/L in mean) into which the outflows of the plants were discharged did not show any significant variations. The domestic DMF load per person was calculated to be 0.25 mg/d/person. The percent DMF loads of domestic effluents in the rivers were estimated to be below (8%–32%). 相似文献
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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
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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
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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
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Maria Cristina Verdenelli Francesca Ghelfi Stefania Silvi Carla Orpianesi Cinzia Cecchini Alberto Cresci 《European journal of nutrition》2009,48(6):355-363
Background
The possibility of using microbes to maintain health, and to prevent or treat disease is a topic as old as microbiology. The research of novel probiotic strains is important in order to satisfy the increasing request of the market and to obtain functional products in which the probiotic cultures are more active and with better probiotic characteristics than those already present on the market. 相似文献14.
Rodriguez JH Carreras HA Pignata ML González CM 《Archives of environmental contamination and toxicology》2007,53(4):533-540
In the present study, the effect of nickel incorporation on the chemical response of Ramalina celastri (Spreng.) Krog & Swinsc. and Usnea amblyoclada (Müll. Arg.) Zahlbr. exposed to urban atmospheric pollutants was assessed. Lichen thalli were treated with Ni solutions and
then transplanted to two areas of the city of Córdoba with different levels of pollution. After exposure, the concentration
of chlorophyll a, chlorophyll b, phaeophytin a, hydroperoxy conjugated dienes, malondialdehyde, sulphur content, electric
conductivity of the immersion water, and nickel content were measured. Also, a Pollution Index was calculated for each lichen
species. The exposure to Ni altered the physiological response to atmospheric pollutants in both lichen species, making them
more sensitive to any damage caused by them. When the species were compared, it was observed that R. celastri accumulated more sulphur than U. amblyoclada. 相似文献
15.
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
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Oyama T Kagawa N Kim YD Matsumoto A Isse T Kawamoto T 《Environmental health and preventive medicine》2003,7(6):230-234
Most chemical carcinogens are metabolized and activated in vivo by phase I enzymes including the microsomal cytochromes P450
and epoxide hydroxylases. The carcinogens and their metabolites are detoxified by phase II enzymes that in clude various transferases
such as glutathion-S-transferases (GST). Increasing numbers of studies have demonstrated the association of the polymorphisms
inGSTM1 (a member of GST) andCYP1A1 genes with the susceptibility to lung cancer. Subsequently, the polymorphisms appear to be important biomarkers that provide
information for assessment of exposure and total burden of environmental carcinogens. Therefore, the investigation of the
polymorphisms in these genes will provide information not only for the prediction of individual cancer risk but also for the
prevention of cancer. In this review, we will summarize the polymorphisms in theGSTM1 andCYP1A1 genes and their relation to lung cancer susceptibility. 相似文献
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Alan M MacEachren Michael S Stryker Ian J Turton Scott Pezanowski 《International journal of health geographics》2010,9(1):23
Background
The volume of health science publications is escalating rapidly. Thus, keeping up with developments is becoming harder as is the task of finding important cross-domain connections. When geographic location is a relevant component of research reported in publications, these tasks are more difficult because standard search and indexing facilities have limited or no ability to identify geographic foci in documents. This paper introduces HEALTH GeoJunction, a web application that supports researchers in the task of quickly finding scientific publications that are relevant geographically and temporally as well as thematically. 相似文献19.
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Mei Liu Xianghu Huang Rui Zhang Changling Li Binhe Gu 《Bulletin of environmental contamination and toxicology》2018,101(5):586-591
The goal of this study was to assess the rate of urea nitrogen uptake (ρ) by Oocystis borgei and the relationship between environmental factors and ρ. Light intensity, temperature, pH, salinity, and algal concentration, were used to construct an empirical model. The results showed that light intensity, algal concentration, pH and salinity had significant effects on ρ, and the optimal combination of environmental conditions for ρ was a temperature of 25°C, pH of 7.0, light intensity of 81 µmol m?2 s?1, salinity of 15‰, and algal concentration of 4.5?×?108 cell L?1–5.5?×?108 cell L?1. The model equation was ρ?=?2?×?10?5?×?(A0.363B0.783C0.045D?0.503E)?+?0.0017, with a coefficient of determination (R2) of 0.83. No significant difference in variance was observed between the model-predicted values and the measured values (F?=?0.238, p?>?0.05), which demonstrated the high fitting degree of the simulation equation. This study provided valuable insight into the reduction of urea nitrogen levels in aquaculture water by O. borgei. 相似文献