GEMAS: Cadmium distribution and its sources in agricultural and grazing land soil of Europe â\u80\u94 Original data versus clr-transformed data

Over 4000 agricultural and grazing land soil samples were collected for the â\u80\u9cGeochemical Mapping of Agricultural and Grazing Land Soil of Europeâ\u80\u9d (GEMAS) project carried out by the EuroGeoSurveys Geochemistry Expert Group. The samples were collected in 33 European countries, covering 5.6 million km2at a density of 1 sample site per 2500 km2. All samples were analysed by ICP-MS following an aqua regia extraction. The European median Cd concentration is 0.182 mg/kg in agricultural soil and 0.197 mg/kg in grazing land soil (including eastern Ukraine). The Cd map demonstrates the existence of two different geochemical background regimes in northern and southern Europe, separated by the southern limit of the Quaternary glaciation. Cadmium shows two times higher background concentrations in the older and more weathered southern European soil than in northern European soil. The spatial distribution patterns of Cd in the collected soil samples are mainly governed by geology (parent material and mineralisation), as well as weathering, soil formation and climate since the last glaciation period. Locally, in several areas, the natural anomaly pattern is overprinted by anthropogenic emissions from former mining, ore processing and related metal industries. Some Cd anomalies can be attributed to urbanisation and the use of fertilisers. A comparison of the raw data Cd concentration map with its clr-transformed counterpart and selected single element ratio maps demonstrates that substantial additional information about sources and processes governing the distribution of Cd in agricultural soil at the European scale can be obtained. Results of a PCA, carried out following the classical approach (standardised) versus a PCA based on the statistically acceptable approach, using clr-transformed data, are quite comparable

GEMAS: Cadmium distribution and its sources in agricultural and grazing land soil of Europe - Original data versus clr-transformed data

Over 4000 agricultural and grazing land soil samples were collected for the “Geochemical Mapping of Agricultural and Grazing Land Soil of Europe” (GEMAS) project carried out by the EuroGeoSurveys Geochemistry Expert Group. The samples were collected in 33 European countries, covering 5.6 million km² at a density of 1 sample site per 2500 km². All samples were analysed by ICP-MS following an aqua regia extraction. The European median Cd concentration is 0.182 mg/kg in agricultural soil and 0.197 mg/kg in grazing land soil (including eastern Ukraine). The Cd map demonstrates the existence of two different geochemical background regimes in northern and southern Europe, separated by the southern limit of the Quaternary glaciation. Cadmium shows two times higher background concentrations in the older and more weathered southern European soil than in northern European soil

GEMAS: Establishing geochemical background and threshold for 53 chemical elements in European agricultural soil

International audienc

GEMAS: establishing geochemical background and threshold for 53 chemical elements in European agricultural soil

The GEMAS (geochemical mapping of agricultural soil) project collected 2108 Ap horizon soil samples from regularly ploughed fields in 33 European countries, covering 5.6 million km2. The <2 mm fraction of these samples was analysed for 53 elements by ICP-MS and ICP-AES, following a HNO3/HCl/H2O (modified aqua regia) digestion. Results are used here to establish the geochemical background variation and threshold values, derived statistically from the data set, in order to identify unusually high element concentrations for these elements in the Ap samples. Potentially toxic elements (PTEs), namely Ag, B, As, Ba, Bi, Cd, Co, Cr, Cu, Hg, Mn, Mo, Ni, Pb, Sb, Se, Sn, U, V and Zn, and emerging ‘high-tech’ critical elements (HTCEs), i.e., lanthanides (e.g., Ce, La), Be, Ga, Ge, In, Li and Tl, are of particular interest. For the latter, neither geochemical background nor threshold at the European scale has been established before. Large differences in the spatial distribution of many elements are observed between northern and southern Europe. It was thus necessary to establish three different sets of geochemical threshold values, one for the whole of Europe, a second for northern and a third for southern Europe. These values were then compared to existing soil guideline values for (eco)toxicological effects of these elements, as defined by various European authorities. The regional sample distribution with concentrations above the threshold values is studied, based on the GEMAS data set, following different methods of determination. Occasionally local contamination sources (e.g., cities, metal smelters, power plants, agriculture) can be identified. No indications could be detected at the continental scale for a significant impact of diffuse contamination on the regional distribution of element concentrations in the European agricultural soil samples. At this European scale, the variation in the natural background concentration of all investigated elements in the agricultural soil samples is much larger than any anthropogenic impact

Use of GEMAS data for risk assessment of cadmium in European agricultural and grazing land soil under the REACH Regulation

Over 4000 soil samples were collected for the “Geochemical Mapping of Agricultural and Grazing Land Soil of Europe” (GEMAS) project carried out by the EuroGeoSurveys Geochemistry Expert Group. Cadmium concentrations are reported for the <2 mm fraction of soil samples from regularly ploughed fields (agricultural soil, Ap, 0–20 cm, N = 2218) and grazing land soil (Gr, 0–10 cm, N = 2127). The samples were collected in 33 European countries, covering 5.6 million km2 at a sample density of 1 sample each per 2500 km2 and were analysed in an aqua regia extraction followed by an ICP-MS finish. The median Cd value is 0.181 mg/kg for the Ap and 0.202 mg/kg for the Gr soil samples. The data allow a directly comparable country-specific regional exposure and risk characterisation for all EU countries covered. Direct risks of Cd for terrestrial organisms are only predicted for a few isolated sample sites: 2.3% of the Ap and 4.5% of the Gr sites, respectively

GEMAS: Establishing geochemical background and threshold for 53 chemical elements in European agricultural soil

The GEMAS (geochemical mapping of agricultural soil) project collected 2108 Ap horizon soil samples from regularly ploughed fields in 33 European countries, covering 5.6 million km2. The &lt;2 mm fraction of these samples was analysed for 53 elements by ICP-MS and ICP-AES, following a HNO3/HCl/H2O (modified aqua regia) digestion. Results are used here to establish the geochemical background variation and threshold values, derived statistically from the data set, in order to identify unusually high element concentrations for these elements in the Ap samples. Potentially toxic elements (PTEs), namely Ag, B, As, Ba, Bi, Cd, Co, Cr, Cu, Hg, Mn, Mo, Ni, Pb, Sb, Se, Sn, U, V and Zn, and emerging ‘high-tech’ critical elements (HTCEs), i.e., lanthanides (e.g., Ce, La), Be, Ga, Ge, In, Li and Tl, are of particular interest. For the latter, neither geochemical background nor threshold at the European scale has been established before. Large differences in the spatial distribution of many elements are observed between northern and southern Europe. It was thus necessary to establish three different sets of geochemical threshold values, one for the whole of Europe, a second for northern and a third for southern Europe. These values were then compared to existing soil guideline values for (eco)toxicological effects of these elements, as defined by various European authorities. The regional sample distribution with concentrations above the threshold values is studied, based on the GEMAS data set, following different methods of determination. Occasionally local contamination sources (e.g., cities, metal smelters, power plants, agriculture) can be identified. No indications could be detected at the continental scale for a significant impact of diffuse contamination on the regional distribution of element concentrations in the European agricultural soil samples. At this European scale, the variation in the natural background concentration of all investigated elements in the agricultural soil samples is much larger than any anthropogenic impact

GEMAS: CNS concentrations and C/N ratios in European agricultural soil

A reliable overview of measured concentrations of TC, TN and TS, TOC/TN ratios, and their regional distribution patterns in agricultural soil at the continental scale and based on measured data has been missing â\u80\u93 despite much previous work on local and the European scales. Detection and mapping of natural (ambient) background element concentrations and variability in Europe was the focus of this work. While total C and S data had been presented in the GEMAS atlas already, this work delivers more precise (lower limit of determination) and fully quantitative data, and for the first time high-quality TN data. Samples were collected from the uppermost 20 cm of ploughed soil (Aphorizon) at 2108 sites with an even sampling density of one site per 2500 km2for one individual land-use class (agricultural) across Europe (33 countries). Laboratory-independent quality control from sampling to analysis guaranteed very good data reliability and accuracy. Total carbon concentrations ranged from 0.37 to 46.3 wt% (median: 2.20 wt%) and TOC from 0.40 to 46.0 wt% (median: 1.80 wt%). Total nitrogen ranged from 0.018 to 2.64 wt% (median: 0.169 wt%) and TS from 0.008 to 9.74 wt% (median: 0.034 wt%), all with large variations in most countries. The TOC/TN ratios ranged from 1.8 to 252 (median: 10.1), with the largest variation in Spain and the smallest in some eastern European countries. Distinct and repetitive patterns emerge at the European scale, reflecting mostly geogenic and longer-term climatic influence responsible for the spatial distribution of TC, TN and TS. Different processes become visible at the continental scale when examining TC, TN and TS concentrations in agricultural soil Europe-wide. This facilitates large-scale land-use management and allows specific areas (subregional to local) to be identified that may require more detailed research