<p>Urban soils are prone to accumulating metals over time. This is caused by the proximity of urban soils to roads and industry, among other sources. In Europe, many urban areas show metal enrichment linked to anthropogenic activity. The public are in contact with urban soils on a regular basis. This potentially has adverse effects on human health, especially in locations with enrichment of metals that are systemic toxicants, such as As, Cd, Cr, Hg and Pb. Despite this, most European countries lack dedicated policy on urban soils. In Ireland, data on urban soil metals exist for only two urban centres (Dublin and Galway), both of which show anthropogenic enrichment of metals. Cork city is an ideal target for study of urban soil metals because its history includes over 200 years of industrial development, and its urban parks include former brownfield and industrial sites. Here, we measured concentrations of urban soil metals for ten sites in Cork city using a portable XRF (X-ray fluorescence) analyser. In addition, two sites were selected for ICP-MS analysis in order to provide an independent test of the accuracy of the XRF data. &#160;Our results show that at all ten Cork sites, Pb is highly enriched in soils, with concentrations up to ten times greater than natural background levels. Fe, Mn and Zn are moderately enriched at each of the ten sites, with concentrations typically between two to five times natural background levels. Metal concentrations are systematically higher at sites in the city centre than suburban sites. These patterns of metal enrichment are similar to those seen in urban soils elsewhere in Europe. Future EU policy is essential for the assessment of urban soils and for the remediation of contaminated sites. This research has already helped to inform the Geological Survey of Ireland and the Government of Ireland Department of the Environment, Climate and Communications to help facilitate the implementation of data-driven legislation. It is anticipated that a relevant soil policy will come into effect in the coming years, which will aid the assessment and remediation of contaminated urban soils across Ireland.&#160;</p>
<p>Soil contamination is widespread across Europe. In particular, contamination of urban soils by metals is poorly characterised. This is a major environmental concern, especially given that urban recreational amenities may be located on former industrial sites and/or may possess ex situ soils derived from industrial areas. We surveyed soils from nine urban recreational sites (15 samples per site) in Cork city in order to assess the degree of metal contamination. The results show that Pb concentrations exceed national background levels in all soil samples from all sites by a mean of 600 % and at least 140 %. Mn, Fe and Zn are enriched above background levels in all soil samples from three (Mn and Fe) to five (Zn) of the sites and, at the remaining sites, show 7 &#8211; 14 localised hotspots. Similar hotspots characterise Cu, Rb and Sr, which each exceed background levels at eight or more sampling locations at four sites. Co, Ni, As and Sn concentrations exceed background levels in at least three hotspots at each of three to six sites. Overall, metal concentrations are highest in the sites closest to the city centre, reflecting diverse sources that potentially include traffic and current and historical domestic coal burning and industry. At each urban site, the element grouping Zn and Pb recurs in 50 to 80 % of locations and enrichment in the element grouping Mn, Fe, Cu, Zn and Pb recurs in approx. 50 % of locations; Ni and As recur in approx. 10 % of the locations. At three sites, elevated concentrations of Mn, Fe, Cu, Zn and Pb are associated with high LOI (Loss-on-ignition) values &#8211; a proxy for the amount of soil organic matter present &#8211; and near-neutral pH values. Conversely, low LOI and acidic pH values are associated with lower concentrations of these elements. This indicates that soil metal concentrations are influenced by the amount of organic matter present and by pH. &#160;Future analyses and experiments will further investigate links between soil organic matter and metal concentrations.</p>
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