Anthropogenic Character Research Articles

Dry atmospheric inputs of trace metals at the Mediterranean coast of Israel (SE Mediterranean): sources and fluxes

This study presents the first detailed data on aerosol concentrations of trace metals (Cd, Pb, Cu, Zn, Cr, Mn, Fe and Al) at the SE Mediterranean coast of Israel, and assesses their sources and fluxes. Aerosol samples were collected at two sampling stations (Tel-Shikmona and Maagan Michael) along the coast between 1994 and 1997. Two broad categories of aerosol trace metal sources were defined; anthropogenic (Cd, Cu, Pb and Zn) and naturally derived elements (Al, Fe, Mn and Cr). The extent of the anthropogenic contribution was estimated by the degree of enrichment of these elements compared to the average crustal composition (EF crust). High values (median >100) were calculated for Cd, Pb and Zn, minor values for Cu and relatively low values (<10) for Fe, Mn and Cr. The crustal-derived elements exhibited a statistically significant seasonal pattern of higher concentrations during spring and autumn (e.g. Al concentrations in some cases during these periods were observed to be in excess of 1500 ng m −3). In the eastern Mediterranean basin crustal-dominated elements are enriched by 2–3 times while others (Cd and Pb) are comparable to the northwestern Mediterranean. The Pb : Cd ratios of ∼150 are higher than in coastal European sites (60–116) or emission materials (∼50). It is speculated that these differences are attributed mainly to the mixing of crustal material with local and European emissions. At present, it is impossible to quantify the latter two fractions. Back trajectory analysis and the subsequent categorization of two main aerosol populations, ‘European’ and ‘North Africa–Arabian’, exhibited a significantly different geochemical imprint on the aerosol chemical composition. ‘European’-derived air masses indicated significantly higher EF crust values for Cd and Pb due to the greater anthropogenic character of the aerosol population, with a dilution by crustal material of this population leading to comparatively lower EF crust values associated with the North African–Arabian air masses.

Statistical analysis of the concentrations of twelve metals in the Ligurian atmospheric aerosol

A correlation analysis based on the concept of singular-value decomposition of a matrix is applied here to an atmospheric aerosol data set, for twelve metals (Al, Ca, Cd, Co, Cu, Fe, Mg, Mn, Na, Ni, Pb and Zn) in the Ligurian Sea coastal environment. An iterative procedure allows atypical samples to be discarded, i.e. samples with characteristics significantly different to those of the whole data set. After five atypical samples have been objectively discarded, the general characteristics of the data set are better described and some features are enhanced according to a decreasing order of importance. For example, the mineral dust character of almost every metal is shown, which points out that the marine recycling component is negligible. Marine (Mg, Na) and anthropogenic (Cd, Cu, Pb, Zn) contributions are assessed as well. There is also evidence of some peculiar behaviours: among others, Fe clearly exhibits an anthropogenic component; the remainder of automotive Pb is still apparent; Ni exhibits a relatively high crustal component; Zn, despite its recognized anthropogenic character, is not clearly correlated with other anthropogenic metals. © 2000 Ifremer/CNRS/IRD/Éditions scientifiques et médicales Elsevier SAS Ligurian Sea / atmospheric aerosol / trace metals / statistical analysis

Socio-technical functioning and anthropogenic crises

Theoretically the barriers of human evolution can be derived from the phenomenon and rules of socio-technical functioning, its interactions with the man-made functional environment. The analysis propounds that most conflicts and crises are of anthropogenic character. The aim of this paper is to map the crises humanity may expect in the future due to its mode of functioning and development. It is not its aim to evaluate different particular aspects of evolutionary perspectives of mankind. The irreconcilable contradictions, like the one between the self-modifying nature of human beings and the self-restoration capability of nature, might become barriers on the road of cognitive evolution. But even antagonistic contradictions can be bridged by creation of specific socio-economic mechanisms. The evolutionary perspectives are epitomized and principles of politics are derived accordingly. © 1998 John Wiley & Sons, Ltd.

Magnetic susceptibility and heavy metals contamination in soils of Southern Poland

The anthropogenic character of the increase in magnetic susceptibility of Silesian soils is doubtless. The dependence between the magnetic susceptibility of industrial dust and the concentration of heavy metals was investigated. Correlation coefficients between those two parameters range for metallurgic dust from 0.911 to 0.998 for Ni and Zn, for fly ashes from 0.710 to 0.820, for Pb and Zn, for cement dust from 0.261 to 0.519 for Ni and Pb, respectively. The anthropogenic character of this dependence is also confirmed by the values of the correlation coefficients between magnetic susceptibility and dust emission, fly ash, metallurgic dust, cement dust, are 0.903, 0.867, 0.918 and 0.365, respectively. For immission the correlation coefficients are as follow: 0.817, 0.656, 0.440 for dustfall, suspended dust and iron fall, respectively. In magnetic particles selected from fly ashes high concentrations of Pb, Zn, Ni and Cu were found. Regarding dependence of magnetic susceptibility on concentration of heavy metals in soils Upper Silesian Industrial Region the correltion coefficients were: between 0.616 - 0.986 for Zn, 0.724 - 0.979 for Pb, and 0.175 - 0.581 for Cd. These values were lower for 90 soil profiles collected from an area of 22 000 km 2 (Katowice Forest State Directorate) resulting from varying conditions of emission and immission of industrial pollutants.

Use of stable lead isotopes and trace metals to characterize air mass sources into the eastern North Atlantic

Stable lead isotopes (204Pb, 206Pb, 207Pb, 208Pb) and trace metals (Mn, Al, Fe, Ni, Cu, Cd, Zn, Pb) have been analyzed in aerosol collected during the Atlantic Stratocumulus Transition Experiment‐Marine Aerosol and Gas Exchange (ASTEX‐MAGE) cruise that transited between Miami and the Azores from May to July 1992. Our goal was to define the continental signatures of the air masses encountered between the Azores and the subtropical regions. The combination of air mass trajectories, trace metal concentrations and stable lead isotopes allowed us to characterize the anthropogenic character of encountered air masses. The average 206Pb/207Pb ratio was 1.148±0.021 and corresponded to a mixing between well defined European (such as Great Britain with 1.115&lt;206Pb/207Pb&lt;1.125 and France with 206Pb/207Pb=1.141±0.000) and North American sources (with 206Pb/207Pb=1.184±0.000). On the basis of air mass trajectories and trace metal concentrations, the background isotopic signature associated with the trade winds (206Pb/207Pb=1.161±0.004) is consistent with previous reports by Church et al. [1990] such as 206Pb/207Pb=1.154±0.004 in 1988, (Véron et al., 1993), 206Pb/207Pb=1.155±0.004 in 1989, and Hamelin et al. [1996] (206Pb/207Pb=1.158±0.006) in 1991. Short‐term variations of continental air mass sources was particularly investigated by considering the anthropogenic character of aerosols collected during two Lagrangian experiments conducted as part of the ASTEX‐MAGE cruise. We demonstrated the utility of stable lead isotopes to assign a “continental source signature” (or mixture thereof) to air masses beyond that normally possible by conventional air mass trajectory analysis in remote oceanic regions.

Chemical composition of acid rain in the North of Spain: The EPOCA program

The EPOCA program (Estudios en el Pirineo Occidental sobre Contaminacion Acida), whose main goal is to show the possible effects of an “acid rain” type pollution on the forests of the Spanish Basque country, is presented in this paper. A measurement network comprising two automatic precipitation collectors located at Vitoria and at Llodio has been operating since December 1985. 30% of the events of rainfall were acidic with a pH ⩽5. However, rain with an alkaline character (pH>6) is found in 25% (Vitoria) and 40% (Lldio) of the cases. The statistical analysis of the chemical components confirms that the chemical contents of the acid rain have an anthropogenic character and those of the alkaline rain a soil origin. Both sources play an important part in the temporal trend of pH values and precipitation chemistry.

Overview of the recent sediment hydrocarbon geochemistry of Atlantic and Gulf Coast outer continental shelf environments

An overview of the hydrocarbon geochemistry of recent marine sediments from the U.S. Atlantic and Gulf of Mexico Outer Continental Shelf (OCS) regions is presented. Hydrocarbon levels along the Atlantic OCS are fairly uniform, ranging between <0·1 and 20 ppm, with the higher values occurring in areas of fine-grained sediment accumulation. Elevated hydrocarbon concentrations appear to be associated with anthropogenic inputs of silt/clay-sized particles to OCS sediments via particulate resuspension and transport, as evidenced by an increase in contributions from the unresolved complex mixture (UCM) feature in gas chromatograms. Compositional characteristics of hydrocarbons in the high-carbonate sediments of the Eastern Gulf OCS indicate a primarily marine origin. Proceeding north and west along the shelf, sedimentary hydrocarbons assume a more terrestrial and/or anthropogenic character in response to a greater input of silt/clays from the Mississippi River. Highest hydrocarbon concentrations in this region (up to 70 ppm) are found in the shallow nearshore areas west of the Mississippi River discharge and in the vicinity of Galveston Bay along the South Texas OCS. In the North Atlantic, Eastern Gulf, South Texas Gulf and coastal Louisiana sediments a linear relationship exists between total hydrocarbon and total organic carbon concentrations, indicating that each area consists of a geochemical ‘province’ defined by a source input or depositional regime specific to the region. The use of trace parameter/bulk parameter ratios (such as total hydrocarbon or individual PAH concentrations/total organic carbon content) in defining such provinces, and thus in serving as a basis for evaluating variations in source inputs as part of future surveys, is demonstrated. This approach views the hydrocarbon content and composition of Atlantic and Gulf coast OCS sediments as points on a spectrum defined by input types (sources) and deposition patterns (sedimentation and erosion), which conceptually link all the regions into a unified system.