Occurrence of selected trace metals and their oral bioaccessibility in urban soils of kindergartens and parks in Bratislava (Slovak Republic) as evaluated by simple in vitro digestion procedure
Abstract
A total of eighty surface soil samples were collected from public kindergartens and urban parks in the city of Bratislava, and the Cu (43.8%) > Cd (40.8%) > Zn (33.6%) > Hg (12.8%). Variations in the bioaccessible metal fractions were mainly related to the total metal concentrations in urban soils.
A relatively wide range of lead isotopic ratios in urban soils (1.1598-1.2088 for Pb-206/Pb-207 isotopic ratio) indicated a combination of anthropogenic and geogenic sources of metals in the soils. Lower values of Pb-206/Pb-207 isotopic ratio in the city centre and similar spatial distribution of total metal concentrations, together with their increasing total concentrations in soils towards the city centre, showed that traffic and coal combustion in former times were likely the major sources of soil contamination.
The non-carcinogenic and carcinogenic health risks to children due to exposure to metals in kindergarten and urban park soils were low, with hazard index and cancer risk values below the threshold values at all studied sites.