Assessment of soil contamination by roof runoff. A case study from Wrocław, Poland

The study focused on the determination of heavy metals originating from anthropogenic sources to assess the environmental and health risks to city residents. The single pollution indices showed the key pollutants in soils such as Zn, Cd, and Pb. Contamination level assessment and the toxicity of pollutants were done by the multi-elemental pollution indices. They showed heavy pollution of tested soils with high eco-logical risk. The correlation analysis and the principal component analysis model were utilized to identify the relative contribution of metals to soil pollution and provide information about the potential sources of metals. The most important for elemental composition in soils in Wrocław are three emission sources: leaching of pollutants from the materials used in the roof coverings and guttering, domestic heating with fossil fuel combustion and other solid materials, leaching of the air pollution including of the road traffic. The health risk analysis shows that ingestion and then dermal contact are the greatest exposure pathways for humans. The health risk was low, although children have greater risks than adults.