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Polychlorinated naphthalenes (PCNs) in Chinese forest soil: Will combustion become a major source? Texte intégral
2015
Xu, Yue | Li, Jun | Zheng, Qian | Pan, Suhong | Luo, Chunling | Zhu, Haolin | Nizzetto, Luca | Zhang, Gan
We collected O- and A-horizon soil samples in 26 Chinese mountainous forests to investigate the content, spatial pattern, and potential sources of polychlorinated naphthalenes (PCNs). Spatial patterns were influenced mainly by the approximation to sources and soil organic contents. High concentrations often occurred close to populated or industrialized areas. Combustion-related activities contributed to PCN pollution. Relatively high proportions of CN-73 in northern China may be attributed to coke consumption, while CN-51 could be an indicator of biomass burning in Southwest China. There are evidences that PCNs may largely derived from unintentional production. If uncontrolled, UP-PCN (unintentionally produced PCNs) emissions could increase with industrial development. The abnormally high concentrations at Gongga and Changbai Mountains appear to be associated with the high efficient of forest filter of atmospheric contaminants at these densely forested sites. We question whether this is caused by ecotones between forests, and raise additional questions for future analyses.
Afficher plus [+] Moins [-]Levels of short chain chlorinated paraffins in pine needles and bark and their vegetation-air partitioning in urban areas Texte intégral
2015
Wang, Thanh | Yu, Junchao | Han, Shanlong | Wang, Yawei | Jiang, Guibin
Short chain chlorinated paraffins (SCCPs) have been of considerable concern in recent years due to their high production volumes, environmental persistency and potential for long range atmospheric transport. Vegetation can take up considerable amounts of semivolatile organic compounds from the atmosphere and can act as indicators of local contamination. Paired pine needles and bark were sampled around Beijing during winter and summertime to investigate the distribution of SCCPs in urban areas. Levels in bark samples ranged 5.79–37.5 μg/g on a lipid normalized basis (lw) with a geometric mean (GM) of 16.9 μg/g lw whereas levels were 3.03–40.8 (GM 11.8) μg/g lw for needles. Average congener group abundance profiles showed equal contribution of all four carbon groups (C10–13) in wintertime whereas higher abundances of C10 and C11 groups were found during summer. Uptake of SCCPs occurred mainly via kinetically limited gaseous deposition and particle bound deposition in the investigated area.
Afficher plus [+] Moins [-]Detection of Copper (II) and Cadmium (II) binding to dissolved organic matter from macrophyte decomposition by fluorescence excitation-emission matrix spectra combined with parallel factor analysis Texte intégral
2015
Yuan, Dong-hai | Guo, Xu-jing | Wen, Li | He, Lian-sheng | Wang, Jing-gang | Li, Jun-qi
Fluorescence excitation-emission matrix (EEM) spectra coupled with parallel factor analysis (PARAFAC) was used to characterize dissolved organic matter (DOM) derived from macrophyte decomposition, and to study its complexation with Cu (II) and Cd (II). Both the protein-like and the humic-like components showed a marked quenching effect by Cu (II). Negligible quenching effects were found for Cd (II) by components 1, 5 and 6. The stability constants and the fraction of the binding fluorophores for humic-like components and Cu (II) can be influenced by macrophyte decomposition of various weight gradients in aquatic plants. Macrophyte decomposition within the scope of the appropriate aquatic phytomass can maximize the stability constant of DOM-metal complexes. A large amount of organic matter was introduced into the aquatic environment by macrophyte decomposition, suggesting that the potential risk of DOM as a carrier of heavy metal contamination in macrophytic lakes should not be ignored.
Afficher plus [+] Moins [-]Organochlorine pesticides in follicular fluid of women undergoing assisted reproductive technologies from central China Texte intégral
2015
Zhu, Yindi | Huang, Bo | Li, Qing X. | Wang, Jun
Female infertility rates have increased by approximately 4% since the 1980s. There is evidence of adverse effects on female fertility in relation to exposure of chemical pollution in recent years. Follicular fluid samples were collected from 127 woman patients (aged 20–35) who underwent assisted reproductive technologies (ART) and had no records indicating occupational exposure to OCPs. Seventeen OCPs were analyzed in this study. The results showed that methoxychlor was dominant, accounted for 13.4% of total OCPs with a mean concentration of 167.9 ± 33.9 ng/g lipid weight (lw), followed by heptachlor-epoxide, hexachlorocyclohexanes, endrin and DDT. The concentrations of OCPs in the follicular fluid samples in the present study were moderate in comparison with those reported from developed or industrialized countries. All these pollutants can accumulate in different tissues of human body through diet, drinking water and respiration. No correlation between patient age and OCP concentrations was observed in this study.
Afficher plus [+] Moins [-]CO2 dose–response functions for wheat grain, protein and mineral yield based on FACE and open-top chamber experiments Texte intégral
2015
Pleijel, Håkan | Högy, Petra
Data from three Swedish open-top chamber and four German FACE experiments were combined to derive response functions for elevated CO2 (eCO2) effects on Cd, Zn, Mn, protein, grain yield, grain mass and grain number of wheat. Grain yield and grain number were increased by ∼6% and ∼7%, respectively, per 100 ppm CO2; the former effect was linked to plant nitrogen status. Grain mass was not influenced by eCO2, whereas Cd concentration was reduced. Unlike Zn, Mn and protein, effects on Cd yield were not related to effects on grain yield. Yields of Mn, Zn and (weakly) protein were positively affected by eCO2. For protein, grain yield, grain mass and grain number, the results were consistent among the FACE and OTC experiments. A key conclusion was that yields of essential nutrients were enhanced (Mn > Zn > protein), although less than grain yield, which would not be expected from a simple dilution model.
Afficher plus [+] Moins [-]Determination of dechlorane flame retardants in soil and fish at Guiyu, an electronic waste recycling site in south China Texte intégral
2015
Tao, Wuqun | Zhou, Zhiguang | Shen, Li | Zhao, Bin
Dechlorane 602 (Dec 602), Dechlorane 603 (Dec 603), Dechlorane 604 (Dec 604), Dechlorane 604 component B (Dec 604 CB) and Dechlorane Plus (DP) were analyzed in soil and fish collected across e-waste recycling sites in Guiyu. The results indicate that soil and fish are contaminated with dechlorane compounds especially Dec 602 and DP which show high concentrations in the samples near recycling sites. Dec 604 and Dec 604 CB are not detected. The photo-degradation experiment indicates that Dec 604 and Dec 604 CB have much faster degradation rates compared to other dechloranes, suggesting they might be more vulnerable to degradation during recycling processes and further studies are needed for assessing the environmental fate and persistence of their degradation products. Dec 602 has not been manufactured in China, the detection of Dec 602 in soil and fish implies that it might be from imports of recyclable materials from developed countries.
Afficher plus [+] Moins [-]Canopy-level stomatal narrowing in adult Fagus sylvatica under O3 stress – Means of preventing enhanced O3 uptake under high O3 exposure? Texte intégral
2015
Matyssek, R. | Baumgarten, M. | Hummel, U. | Häberle, K.-H. | Kitao, M. | Wieser, G.
Spatio-temporally consistent O3 doses are demonstrated in adult Fagus sylvatica from the Kranzberg Forest free-air fumigation experiment, covering cross-canopy and whole-seasonal scopes through sap flow measurement. Given O3-driven closure of stomata, we hypothesized enhanced whole-tree level O3 influx to be prevented under enhanced O3 exposure. Although foliage transpiration rate was lowered under twice-ambient O3 around noon by 30% along with canopy conductance, the hypothesis was falsified, as O3 influx was raised by 25%. Nevertheless, the twice-ambient/ambient ratio of O3 uptake was smaller by about 20% than that of O3 exposure, suggesting stomatal limitation of uptake. The O3 response was traceable from leaves across branches to the canopy, where peak transpiration rates resembled those of shade rather than sun branches. Rainy/overcast-day and nightly O3 uptake is quantified and discussed. Whole-seasonal canopy-level validation of modelled with sap flow-derived O3 flux becomes available in assessing O3 risk for forest trees.
Afficher plus [+] Moins [-]Multigenerational contaminant exposures produce non-monotonic, transgenerational responses in Daphnia magna Texte intégral
2015
Kimberly, David A. | Salice, Christopher J.
Generally, ecotoxicologists rely on short-term tests that assume populations to be static. Conversely, natural populations may be exposed to the same stressors for many generations, which can alter tolerance to the same (or other) stressors. The objective of this study was to improve our understanding of how multigenerational stressors alter life history traits and stressor tolerance. After continuously exposing Daphnia magna to cadmium for 120 days, we assessed life history traits and conducted a challenge at higher temperature and cadmium concentrations. Predictably, individuals exposed to cadmium showed an overall decrease in reproductive output compared to controls. Interestingly, control D. magna were the most cadmium tolerant to novel cadmium, followed by those exposed to high cadmium. Our data suggest that long-term exposure to cadmium alter tolerance traits in a non-monotonic way. Because we observed effects after one-generation removal from cadmium, transgenerational effects may be possible as a result of multigenerational exposure.
Afficher plus [+] Moins [-]Contrasts in spatial and temporal variability of oxidative capacity and elemental composition in moxibustion, indoor and outdoor environments in Beijing Texte intégral
2015
Huang, Jian | Lim, Min Yee | Hwang, Chaxi | Zhao, Baixiao | Shao, Longyi
Moxibustion is a traditional Chinese medicine therapy that burns moxa floss which produces a substantial amount of PM10 into the environment, thus spawning safety concerns about health impacts of the smoke. We compared the oxidative capacity and elemental composition of moxibustion-derived and ambient PM10 in summer and winter to provide a source-, spatial- and temporal-comparison of PM10 biological responses. The PM10 oxidative capacity was 2.04 and 1.45 fold lower, and dose-dependent slope gradient was 2.36 and 1.76 fold lower in moxibustion environment than indoor or outdoor. Oxidative damage was highly correlated with iron, cesium, aluminum and cobalt in indoor, but moxibustion environment displayed low associations. The total elemental concentration was also lower in moxibustion environment than indoor (2.28 fold) or outdoor (2.79 fold). The source-to-dose modeling and slope gradient analysis in this study can be used as a model for future source-, spatial- and temporal-related moxibustion safety evaluation studies.
Afficher plus [+] Moins [-]How life history influences the responses of the clam Scrobicularia plana to the combined impacts of carbamazepine and pH decrease Texte intégral
2015
Freitas, Rosa | Almeida, Angela Maria da | Calisto, Vânia | Velez, Cátia | Moreira, Anthony | Schneider, Rudolf J. | Esteves, Valdemar I. | Wrona, Frederick J. | Soares, Amadeu M.V. M. | Figueira, Etelvina
How life history influences the responses of the clam Scrobicularia plana to the combined impacts of carbamazepine and pH decrease Texte intégral
2015
Freitas, Rosa | Almeida, Angela Maria da | Calisto, Vânia | Velez, Cátia | Moreira, Anthony | Schneider, Rudolf J. | Esteves, Valdemar I. | Wrona, Frederick J. | Soares, Amadeu M.V. M. | Figueira, Etelvina
In the present study, the bivalve Scrobicularia plana, collected from two contrasting areas (pristine location and mercury contaminated area), was selected to assess the biochemical alterations imposed by pH decrease, carbamazepine (an antiepileptic) and the combined effect of both stressors. The effects on oxidative stress related biomarkers after 96 h exposure revealed that pH decrease and carbamazepine induced alterations on clams, with greater impacts on individuals from the contaminated area which presented higher mortality, higher lipid peroxidation and higher glutathione S-transferase activity. These results emphasize the risk of extrapolating results from one area to another, since the same species inhabiting different areas may be affected differently when exposed to the same stressors. Furthermore, the results obtained showed that, when combined, the impact of pH decrease and carbamazepine was lower than each stressor acting alone, which could be related to the defence mechanism of valves closure when bivalves are under higher stressful conditions.
Afficher plus [+] Moins [-]How life history influences the responses of the clam Scrobicularia plana to the combined impacts of carbamazepine and pH decrease Texte intégral
1000 | 2015
Freitas, Rosa | Almeida, Ângela | Calisto, Vânia | Velez, Cátia | Moreira, Anthony | Schneider, Rudolf J. | Esteves, Valdemar I. | Wrona, Frederick J. | Soares, Amadeu M. V. M. | Figueira, Etelvina
In the present study, the bivalve Scrobicularia plana, collected from two contrasting areas (pristine location and mercury contaminated area), was selected to assess the biochemical alterations imposed by pH decrease, carbamazepine (an antiepileptic) and the combined effect of both stressors. The effects on oxidative stress related biomarkers after 96 h exposure revealed that pH decrease and carbamazepine induced alterations on clams, with greater impacts on individuals from the contaminated area which presented higher mortality, higher lipid peroxidation and higher glutathione S-transferase activity. These results emphasize the risk of extrapolating results from one area to another, since the same species inhabiting different areas may be affected differently when exposed to the same stressors. Furthermore, the results obtained showed that, when combined, the impact of pH decrease and carbamazepine was lower than each stressor acting alone, which could be related to the defence mechanism of valves closure when bivalves are under higher stressful conditions.
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