Genotoxic damage in coelomocytes of Eisenia andrei exposed to urban soils

Based on the hypothesis that urban activities can deposit chemical contaminants in soil and consequently have an impact on the vitality of key organisms of the ecosystem, the aim of the present study was to analyse genotoxicity in earthworm's coelomocytes in urban soil samples in comparison to soil samples from protected areas. Earthworms (Eisenia andrei) were exposed to soil samples for 14 days, subsequently the coelomocytes were extracted with an 10% ethanol solution and used in single cell gel electrophoresis (SCGE) assay and the micronucleus (MN) assay. The levels of copper, cadmium, lead, zinc, and arsenic were measured in monitored soil samples. Earthworms exposed to urban soils had higher levels of DNA damage, according to the results of the SCGE assay, than earthworms exposed to protected area soils. The frequency of micronuclei did not differ between the studied soil samples. There was an association between % DNA (SCGE assay) and arsenic and zinc levels. Copper, lead and zinc levels in urban soil samples exceeded the limits of legal values in Brazil. Our findings show that the genotoxicity markers we tested are sensitive to contamination and this association should be taken into account by regulatory agencies.