heavy metals

pH

soil pollution

suburban recreational area

Allium cepa-test

Physicochemical parameters

Pollution

Others

Flood and drought risk

Increasing attention has been paid recently to soil pollution. The aim of this study was to evaluate the ecological risk of soils collected from Nature Park Shumen Plateau (Bulgaria) (NP) using physicochemical and cytogenetic approaches (pH analysis, analysis of the content of heavy metals included in Bulgarian soil pollution standards, and Allium cepa-test). Soil samples from NP were collected from seven sites. A sample from a heavily anthropogenic-influenced urban site was also collected. As signs for environmental risk used pH values, we found total concentration of heavy metals and mitotic abnormalities in Allium cepa root meristems included in Bulgarian legislation. Only two samples from NP were found to be slightly acidic. The other samples have slightly alkaline pH. The highest pH value was obtained in the urban sample. Heavy metal concentrations did not exceeded national standards for soil pollution. Several NP samples and urban samples exerted cytotoxic and genotoxic effects in Allium root meristems. Our data on soil pH and heavy metal concentrations did not indicate potential ecological risk, but cytogenetic endpoints showed the presence of harmful compounds in studied areas. In conclusion, the ecological risk for the investigated suburban area may be assessed as moderate.