Bioindicators use for evaluation of heavy metal concentrations in urban parks

The environmental quality of urban soil is closely related to human health. The heavy metals increase in urban environments was due to the anthropic activity. The urban parks monitoring in three cities of Emilia Romagna region (Bologna, Cesena and Ferrara) were carried out to determined the heavy metals and microelements concentration in the tissues of mosses, grass and leaf of coniferous and deciduous trees. The airborne pollutants was studied by washing and analysing the heavy metals concentration in washed-leaves water. The aim of the study was twofold: to find an integrations between different environmental compartments (vegetation and washed-leaves water) and to highlight the different contribution of pollution sources. The sampling campaign was carried out in two different seasons (Spring 2006 and Winter 2007) and involved taking samples of grass, mosses, leaves of deciduous and coniferous trees and washed-leaves water. The samples collected were suitably treated and analysed by means of optical emission spectrometry using a CCD detector (ICP-OES, Spectro CIR.O.S.CCD). Integrated analysis of the different environmental matrixes permitted identification of the most critical sites, respect to the heavy metals and microelements concentration. The strong correlation between the concentrations found in the moss, grasses and washed-leaves water underlines how the urban parks in Bologna and Ferrara are highly susceptible to atmospheric pollution.