Spatial distribution of total Hg in urban soils from an Atlantic coastal city (Aveiro, Portugal)

The aim of this study was to investigate the levels and the spatial distribution of total Hg concentrations in soils from the urban area of Aveiro (Portugal) in order to assess the impact of industrial activities and identified Hg emission sources in these urban soils. For this purpose, soils were collected in 25 sampling points (at two depths) within the urban perimeter and in places considered representative of the main green areas of the city. A median concentration of 0.091 mg kg 1 (dry weight) was obtained, regardless the depth. Aveiro was considered a low polluted city in terms of total Hg and no direct effects of emissions of Hg from industrial activities nearby could be detected in these urban soils. Despite of the low values obtained, high variability (range of 60.5 mg kg 1) was observed in the results. Such was considered to be related to characteristic features of soils in urban settings and to the behaviour of Hg in the urban environment.