Organochlorine pesticides (OCP) were monitored at the Weissfluhjoch site (Switzerland) and the top of Mt. Sonnblick (Austria) with a low volume active air sampler and semipermeable membrane devices (SPMD). The air sam...Organochlorine pesticides (OCP) were monitored at the Weissfluhjoch site (Switzerland) and the top of Mt. Sonnblick (Austria) with a low volume active air sampler and semipermeable membrane devices (SPMD). The air sampling rates (Rair) of the SPMD for OCP were calculated. Statistical tests showed that there was no significant difference between Rair at the two different sampling sites. Quantitative structure-property relationship (QSPR) models of the Rair of the SPMD were developed for OCP using partial least square (PLS) regression. Quantum chemical descriptors computed by the semi-empirical PM6 method were used as predictor variables. The cumulative variance of the dependent variable explained by the PLS components and determined by cross-validation (Q2cum) was >0.818 for each optimal model. This indicates that the model has good predictive ability and robustness. The Rair of the SPMD for OCP is related to the total energy, the van der Waals area and the total dipole moment of the OCP molecules. The main factors governing Rair values of OCP are intermolecular interactions and the energy required for cavity-formation in dissolution of OCP into triolein of the SPMD. The linear correlation coefficient between predicted and experimental values were all >0.921.展开更多
In the first tier risk assessment（RA） of pesticides, risk for aquatic communities is estimated by using results from standard laboratory tests with algae, daphnids and fish for single pesticides such as herbicides, ...In the first tier risk assessment（RA） of pesticides, risk for aquatic communities is estimated by using results from standard laboratory tests with algae, daphnids and fish for single pesticides such as herbicides, fungicides, and insecticides. However, fungi as key organisms for nutrient cycling in ecosystems as well as multiple pesticide applications are not considered in the RA. In this study, the effects of multiple low pesticide pulses using regulatory acceptable concentrations（RACs） on the dynamics of non-target aquatic fungi were investigated in a study using pond mesocosm. For that, fungi colonizing black alder（Alnus glutinosa） leaves were exposed to multiple, low pulses of 11 different pesticides over a period of 60 days using a real farmer＇s pesticide application protocol for apple cropping.Four pond mesocosms served as treatments and 4 as controls. The composition of fungal communities colonizing the litter material was analyzed using a molecular fingerprinting approach based on the terminal Restriction Fragment Length Polymorphism（t-RFLP） of the fungal Internal Transcribed Spacer（ITS） region of the ribonucleic acid（RNA） gene（s）. Our data indicated a clear fluctuation of fungal communities based on the degree of leaf litter degradation. However significant effects of the applied spraying sequence were not observed. Consequently also degradation rates of the litter material were not affected by the treatments. Our results indicate that the nutrient rich environment of the leaf litter material gave fungal communities the possibility to express genes that induce tolerance against the applied pesticides. Thus our data may not be transferred to other fresh water habitats with lower nutrient availability.展开更多
基金supported by the National Natural Science Foundation of China (20877011)the State Key Laboratory of Environmental Chemistry and Ecotoxicology, Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences (KF2009-17)+2 种基金the Key Laboratory of Industrial Ecology and Environmental Engineering, China Ministry of Education (0802)Scientific Research Foundation for Returned Overseas Chinese ScholarsThe Monitoring Network in the Alpine Region for Persistent and other Organic Pollutants, MONARPOP, was funded by the EU Interreg III B Alpine Space Programme (Alpine Space) and by the participating partners
文摘Organochlorine pesticides (OCP) were monitored at the Weissfluhjoch site (Switzerland) and the top of Mt. Sonnblick (Austria) with a low volume active air sampler and semipermeable membrane devices (SPMD). The air sampling rates (Rair) of the SPMD for OCP were calculated. Statistical tests showed that there was no significant difference between Rair at the two different sampling sites. Quantitative structure-property relationship (QSPR) models of the Rair of the SPMD were developed for OCP using partial least square (PLS) regression. Quantum chemical descriptors computed by the semi-empirical PM6 method were used as predictor variables. The cumulative variance of the dependent variable explained by the PLS components and determined by cross-validation (Q2cum) was >0.818 for each optimal model. This indicates that the model has good predictive ability and robustness. The Rair of the SPMD for OCP is related to the total energy, the van der Waals area and the total dipole moment of the OCP molecules. The main factors governing Rair values of OCP are intermolecular interactions and the energy required for cavity-formation in dissolution of OCP into triolein of the SPMD. The linear correlation coefficient between predicted and experimental values were all >0.921.
文摘In the first tier risk assessment（RA） of pesticides, risk for aquatic communities is estimated by using results from standard laboratory tests with algae, daphnids and fish for single pesticides such as herbicides, fungicides, and insecticides. However, fungi as key organisms for nutrient cycling in ecosystems as well as multiple pesticide applications are not considered in the RA. In this study, the effects of multiple low pesticide pulses using regulatory acceptable concentrations（RACs） on the dynamics of non-target aquatic fungi were investigated in a study using pond mesocosm. For that, fungi colonizing black alder（Alnus glutinosa） leaves were exposed to multiple, low pulses of 11 different pesticides over a period of 60 days using a real farmer＇s pesticide application protocol for apple cropping.Four pond mesocosms served as treatments and 4 as controls. The composition of fungal communities colonizing the litter material was analyzed using a molecular fingerprinting approach based on the terminal Restriction Fragment Length Polymorphism（t-RFLP） of the fungal Internal Transcribed Spacer（ITS） region of the ribonucleic acid（RNA） gene（s）. Our data indicated a clear fluctuation of fungal communities based on the degree of leaf litter degradation. However significant effects of the applied spraying sequence were not observed. Consequently also degradation rates of the litter material were not affected by the treatments. Our results indicate that the nutrient rich environment of the leaf litter material gave fungal communities the possibility to express genes that induce tolerance against the applied pesticides. Thus our data may not be transferred to other fresh water habitats with lower nutrient availability.
