Urban soils are often contaminated by metals deriving from human activities. Urban polluted soils can affect human health through direct physical contact or through the food chain. The behaviour of metals is affected by chemical and physical soil properties. Heavy metal concentration was determined in some soils of three medium sized towns of coastal Tuscany, Central Italy. Soil samples were collected in roadsides, urban agricultural soils (allotments), playgrounds and public parks. The analysis included total metal content (Pb, Cu, Zn, Ni, Cd), and sequential extraction. Lead reached the highest levels in the soils and was higher near roads. In urban agricultural soils and in allotments Cu was present in noticeable quantities (300 mg kg(-1)). The presence of Cu in urban soils seems to be typical of soils used for a long period as agricultural land, especially vineyards in the area covered by this study. Sequential extraction was performed to evaluate the mobility of the metals and to better understand the impact of the anthropogenic activity on urban sites. In the present study principal components analysis (PCA) is employed to describe the characteristics of urban soils.

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This study assessed the distribution and availability of plant uptake of Zn, Pb, and Cd present in an abandoned mine at Ingurtosu, Sardinia (Italy). Geological matrix samples (sediments, tailings, and soil from a nearby pasture site) and samples of the predominant plant species growing on sediments and tailings were collected. Mean values of total Zn, Pb and Cd were respectively (mg kg(-1)) 7400, 1800, and 56 in tailings, 31000, 2900, and 100 in sediments, and 400, 200, and 8 in the pasture soil. The metal concentration values were high even in the mobile fractions evaluated by simplified sequential extraction (Zn 7485-103, Pb 1015-101, Cd 47-4 mg kg(-1)). Predominant native species were identified and analyzed for heavy metal content in various tissues. Among the plant species investigated Inula viscosa, Euphorbia dendroides, and Poa annua showed the highest metal concentration in aboveground biomass (mean average of Zn: 1680, 1020, 1400; Pb: 420, 240, 80; Cd: 28, 7, 19 mg kg(-1), respectively). The above mentioned species and A. donax could be good candidates for a phytoextraction procedure. Cistus salvifolius and Helichrysum italicus generally showed behavior more suitable for a phytostabilizer.

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The growing importance of urban allotments in planning and managing urban areas is due to the combined positive effects on ecosystem services, the economy and human well-being, especially of groups of the urban population that can be vulnerable (e.g. the elderly, immigrants, low-income families). Some studies have highlighted the potential risk of contamination by metals of vegetables grown in urban areas and the lack of appropriate site-specific risk assessments. However, surveys are still lacking on the possibilities of using urban soil as a good substrate to produce vegetables for home consumption. We assessed the soil quality in two areas in Pisa (Italy), one intended for urban horticulture and the other already cultivated for that purpose. We analysed the soils for the main chemical and physical characteristics (texture, bulk density, water stability index, pH, cation exchange capacity, organic carbon, total nitrogen, phosphorous) and elements (Pb, Cu, Ni, Cr, Zn, Cd, As, K, Al and Mn). Our results showed that both areas had physical and chemical heterogeneity due to the effects of urbanization and to the different cultivation techniques employed. The metal content was lower than the guidelines limits, and the soil conditions (pH = 8) greatly reduced the metal mobility. Copper concentration in some of the cultivated area samples was higher than the limits, representing a possible stress factor for the microbial biodiversity and fauna. Our findings demonstrate that site-specific surveys are necessary before planning urban cultivation areas, and educating urban gardeners regarding sustainable cultivation techniques is a priority for a safe environment.

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According to projects and practices that the Italian botanists and ecologists are carrying out for bringing "more nature in the city", new insights for a factual integration between ecological perspectives and more consolidated aesthetic and agronomic approaches to the sustainable planning and management of urban green areas are provided.Keywords Ecosystem services, Human well-being, Green infrastructure, Urban green areas, Urban biodiversity.