Land use influences on soil geochemistry in Lefkosia (Nicosia) Cyprus

Abstract

The city of Lefkosia (Nicosia) on the Mesaoria Plain of Cyprus has been populated since the Bronze Age. A detailed survey of the city and surrounding suburban area has been undertaken to assess the relationship between land use, geology and soil geochemistry. In total, 441 soil samples were collected from 10 to 20cm depth and analysed by ICP-MS following an aqua regia digestion. The main controls on major and most trace element concentrations are geogenic, with parent lithology and adsorption of metals on secondary Fe/Mn minerals dominating. A number of metals are relatively enriched in the soil of industrial and commercial areas, with the patterns for Ag, Sn and Sb indicating the preservation of historical metal contamination around the old city, and elevated Pb and Zn in areas currently zoned for residential or industrial purposes. The geochemistry of school yard soil generally displays a basaltic signature, with high Fe, Mn, Cu and Zn compared with surrounding sites. Children's' playgrounds have low trace element concentrations that are typical of soil developed from the carbonate-rich lithologies on the island. However, a high proportion of the playgrounds contain elevated As concentrations (>10mg/kg) that can be linked to a particular source of transported fill. Factors such as the presence of fill and restricted zones of element contamination reduce the spatial correlation of the soil geochemical data compared with non-urban areas. By comparison with the preceding soil geochemical atlas of Cyprus, the soil of Lefkosia contains higher average Ag, Pb and Zn concentrations, but few individual values for these or other elements exceed existing regulatory limits in various EU member countries. The results will assist in developing regulatory values for chemical elements in Cypriot urban soil that take into account the influence of geogenic factors and also indicate the need for regulation in the use of land fill or transported soil.