排序方式: 共有24条查询结果,搜索用时 15 毫秒
21.
Didier Brunet Thierry Woignier Magalie Lesueur-Jannoyer Raphaël Achard Luc Rangon Bernard G. Barths 《Environmental pollution (Barking, Essex : 1987)》2009,157(11):3120-3125
Chlordecone is a toxic organochlorine insecticide that was used in banana plantations until 1993 in the French West Indies. This study aimed at assessing the potential of near infrared reflectance spectroscopy (NIRS) for determining chlordecone content in Andosols, Nitisols and Ferralsols from Martinique. Using partial least square regression, chlordecone content conventionally determined through gas chromatography–mass spectrometry could be correctly predicted by NIRS (Q2 = 0.75, R2 = 0.82 for the total set), especially for samples with chlordecone content <12 mg kg−1 or when the sample set was rather homogeneous (Q2 = 0.91, R2 = 0.82 for the Andosols). Conventional measures and NIRS predictions were poorly correlated for chlordecone content >12 mg kg−1, nevertheless ca. 80% samples were correctly predicted when the set was divided into three or four classes of chlordecone content. Thus NIRS could be considered a time- and cost-effective method for characterising soil contamination by chlordecone. 相似文献
22.
Florence Clostre Magalie Lesueur-Jannoyer Raphaël Achard Philippe Letourmy Yves-Marie Cabidoche Philippe Cattan 《Environmental science and pollution research international》2014,21(3):1980-1992
When field pollution is heterogeneous due to localized pesticide application, as is the case of chlordecone (CLD), the mean level of pollution is difficult to assess. Our objective was to design a decision support tool to optimize soil sampling. We analyzed the CLD heterogeneity of soil content at 0–30- and 30–60-cm depth. This was done within and between nine plots (0.4 to 1.8 ha) on andosol and ferralsol. We determined that 20 pooled subsamples per plot were a satisfactory compromise with respect to both cost and accuracy. Globally, CLD content was greater for andosols and the upper soil horizon (0–30 cm). Soil organic carbon cannot account for CLD intra-field variability. Cropping systems and tillage practices influence the CLD content and distribution; that is CLD pollution was higher under intensive banana cropping systems and, while upper soil horizon was more polluted than the lower one with shallow tillage (<40 cm), deeper tillage led to a homogenization and a dilution of the pollution in the soil profile. The decision tool we proposed compiles and organizes these results to better assess CLD soil pollution in terms of sampling depth, distance, and unit at field scale. It accounts for sampling objectives, farming practices (cropping system, tillage), type of soil, and topographical characteristics (slope) to design a relevant sampling plan. This decision support tool is also adaptable to other types of heterogeneous agricultural pollution at field level. 相似文献
23.
Laurent Lanceleur Jörg Schäfer Gérard Blanc Alexandra Coynel Cécile Bossy Magalie Baudrimont Corine Glé Aurélie Larrose Sophie Renault Emilie Strady 《Environmental science and pollution research international》2013,20(3):1352-1366
Dissolved and particulate Ag concentrations (AgD and AgP, respectively) were measured in surface water and suspended particulate matter (SPM) along the salinity gradient of the Gironde Estuary, South West France, during three cruises (2008–2009) covering contrasting hydrological conditions, i.e. two cruises during intermediate and one during high freshwater discharge (~740 and ~2,300 m3/s). Silver distribution reflected non-conservative behaviour with 60–70 % of AgP in freshwater particles being desorbed by chlorocomplexation. The amount of AgP desorbed was similar to the so-called reactive, potentially bioavailable AgP fraction (60?±?4 %) extracted from river SPM by 1 M HCl. Both AgP (0.22?±?0.05 mg/kg) and AgP/ThP (0.025–0.028) in the residual fraction of fluvial and estuarine SPM were similar to those in SPM from the estuary mouth and in coastal sediments from the shelf off the Gironde Estuary, indicating that chlorocomplexation desorbs the reactive AgP. The data show that desorption of reactive AgP mainly occurs inside the estuary during low and intermediate discharge, whereas expulsion of partially AgP-depleted SPM (AgP/ThP ~0.040) during the flood implies ongoing desorption in the coastal ocean, e.g. in the nearby oyster production areas (Marennes-Oléron Bay). The highest AgD levels (6–8 ng/L) occurred in the mid-salinity range (15–20) of the Gironde Estuary and were decoupled from freshwater discharge. In the maximum turbidity zone, AgD were at minimum, showing that high SPM concentrations (a) induce AgD adsorption in estuarine freshwater and (b) counterbalance AgP desorption in the low salinity range (1–3). Accordingly, Ag behaviour in turbid estuaries appears to be controlled by the balance between salinity and SPM levels. The first estimates of daily AgD net fluxes for the Gironde Estuary (Boyle’s method) showed relatively stable theoretical AgD at zero salinity (Ag D 0 = 25–30 ng/L) for the contrasting hydrological situations. Accordingly, AgD net fluxes were very similar for the situations with intermediate discharge (1.7 and 1.6 g/day) and clearly higher during the flood (5.0 g/day) despite incomplete desorption. Applying Ag D 0 to the annual freshwater inputs provided an annual net AgD flux (0.64–0.89 t/year in 2008 and 0.56–0.77 t/year in 2009) that was 12–50 times greater than the AgD gross flux. This estimate was consistent with net AgD flux estimates obtained from gross AgP flux considering 60 % desorption in the estuarine salinity gradient. 相似文献
24.
Lanceleur L Schäfer J Chiffoleau JF Blanc G Auger D Renault S Baudrimont M Audry S 《Chemosphere》2011,85(8):1299-1305
The Gironde fluvial estuarine system is impacted by historic metal pollution (e.g. Cd, Zn, Hg) and oysters (Crassostrea gigas) from the estuary mouth have shown extremely high Cd concentrations for decades. Based on recent work (Chiffoleau et al., 2005) revealing anomalously high Ag concentrations (up to 65 mg kg−1; dry weight) in Gironde oysters, we compared long-term (∼1955-2001) records of Ag and Cd concentrations in reservoir sediment with the respective concentrations in oysters collected between 1979 and 2010 to identify the origin and historical trend of the recently discovered Ag anomaly. Sediment cores from two reservoirs upstream and downstream from the main metal pollution source provided information on (i) geochemical background (upstream; Ag: ∼0.3 mg kg−1; Cd: ∼0.8 mg kg−1) and (ii) historical trends in Ag and Cd pollution. The results showed parallel concentration-depth profiles of Ag and Cd supporting a common source and transport. Decreasing concentrations since 1986 (Cd: from 300 to 11 mg kg−1; Ag: from 6.7 to 0.43 mg kg−1) reflected the termination of Zn ore treatment in the Decazeville basin followed by remediation actions. Accordingly, Cd concentrations in oysters decreased after 1988 (from 109 to 26 mg kg−1, dry weight (dw)), while Ag bioaccumulation increased from 38 up to 116 mg kg−1, dw after 1993. Based on the Cd/Ag ratio (Cd/Ag ∼ 2) in oysters sampled before the termination of zinc ore treatment (1981-1985) and assuming that nearly all Cd in oysters originated from the metal point source, we estimated the respective contribution of Ag from this source to Ag concentrations in oysters. The evolution over the past 30 years clearly suggested that the recent, unexplained Ag concentrations in oysters are due to increasing contributions (>70% after 1999) by other sources, such as photography, electronics and emerging Ag applications/materials. 相似文献