engleski

SOURCES OF POTENTIALLY TOXIC ELEMENTS IN PLAYGROUND SOILS OF ZAGREB (CROATIA)

Guidance values for potentially toxic elements (PTE) in soils for child-care centers and playgrounds have not been developed in Croatia. An evaluation of soil concentrations of PTE for 150 child-care centers and 50 playgrounds in Zagreb determined that Pb, Hg, P, (Cu) Sb, Ag (Au) can be attributed as an anthropogenic pollution signature. Road dust contribution seems to be the major source of PTE to the playground soils, although lead paint from old playing equipment could also considerably contribute to pollution of the soils.In the case of Pb, Sb, Hg and Cu their anthropogenic input through industrial and urban development is also shown with higher mean concentrations in the subsoil mainly restricted to the central (old) parts of the city. Lead and Hg show the most number of outliers with anomalous values. The PCA extracted 5 major components responsible for variation in elemental distribution. The first factor contains a signal from the influence of lithological bedrock composition (Ca, Mg, Al, Fe, Th, Co, Cr, Ni), the second (Fig. 1) shows the Pb, Hg, P, (Cu) Sb, Ag (Au) attributed as an anthropogenic pollution signature. The significant inputs of anthropogenic origin are present in 20% of the playgrounds. Most analyzed old paints from playing equipment we identified as lead-based paint (Pb content >0, 5%). In 16 the composite topsoil contained more 100 mg/kg Pb. Lead, Hg, As, Zn, Cd and Cu concentrations in topsoils were found to be higher than those defined by health-based soil quality criteria at 10% of the child-care playgrounds. The association of Sb with Pb (r=0.8) in soils indicates that a large part of lead in the soil is derived from road dust since Sb in urban soils has been attributed to wear of brake linings (MÅNSSON, et al., 2009). The 206Pb/207Pb ratios of analysed soils with elevated Pb concentraions and paint chips have ratio values of <1.11 which is similar to 206Pb/207Pb ratios of road dust in Croatia (1.08-1.12) and which is mainly attributed to petrol lead influence.

playground; soil; lead; pollution; Pb isotopes; Zagreb

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