An inventory of trace elements inputs to French agricultural soils.

The inputs of ten trace elements (As, Cd, Cu, Cr, Hg, Mo, Ni, Pb, Se, Zn) to French agricultural soils have been assessed. The six main sources considered were: pesticides, mineral fertilizers, animal manure, liming materials, sludge and composts and atmospheric deposition. Data were collected to compute inputs at both national and regional (departmental) scales. The inventory methodology is based on two principles: data are traceable and easy to update. At a national scale, the inventory showed that trace elements inputs can be ranked: Zn≫Cu≫Cr>Pb>Ni>As=Mo>Se>Cd>Hg. Animal manure, mineral fertilizers and pesticides are the predominant sources of TEs. These results are globally in agreement with literature data though atmospheric deposition is shown to be lower than in more industrial countries such as China and United Kingdom where similar surveys were conducted. The inputs of trace elements vary strongly between regions in relation with agricultural activities. This inventory (and the related database) provides basis for developing and monitoring policies to control and reduce trace elements contamination of agricultural soils at both national and regional (departmental) scales.

Multianalysis of trace elements in mosses with inductively coupled plasma-mass spectrometry.

As a part of an air-pollution biomonitoring survey, a procedure using inductively coupled plasma-mass spectrometry (ICP-MS) and microwave digestion was developed to achieve a high sample throughput and guarantee the accuracy of the results. This article presents an analytical method to measure 22 trace elements. As, Ba, Cd, Ce, Co, Cr, Cs, Cu, Fe, Hg, La, Mo, Ni, Pb, Rb, Sb, Sr, Th, Tl, U, V, W were analyzed in 563 mosses collected in France. The digestion was performed in polytetrafluoroethylene (PTFE) vessel using the mixture HNO3-H2O2-HF. The data were reprocessed taking into account the drift curve calculated for each element. The detection limits (DL) calculation was based on the standard deviations of the reagent blanks concentrations. The DL varied from one batch to another, because of the heterogeneity of the mosses' elemental contents. The DL ranged between 0.001 microg/g (Cs, Tl) and 70 microg/g (Fe) and were mainly around 0.01 microg/g (As, Cd, Ce, Co, Hg, La, Mo, Sb, Sr, U, V, W). The detection limits obtained were in agreement with the concentrations observed in the samples, except for Hg and Ni. The reproducibility between duplicates and the analytical precision were near 10%. The procedure was tested with the mosses' reference materials.