Biochemical and molecular alterations in freshwater mollusks as biomarkers for petroleum product, domestic heating oil

Level of oxidative stress for the land snail Cepaea nemoralis from aged and bioremediated soil contaminated with petroleum products

Here, we investigated whether the widely distributed snail Cepaea nemoralis could be used as a suitable sentinel animal for assessing the effects of soil contaminants-petroleum oil derivatives-after years of soil ageing and treatment with a bacterial formulation. Oxidative stress was assessed in the foot and hepatopancreas of C. nemoralis L. exposed to soil contaminated with unleaded petrol, spent engine oil or diesel oil and bioremediated with a bacterial formulation (soil was used 2 years after contamination and bioremediation process). We measured total antioxidant capacity, catalase and glutathione transferase activity and concentrations of superoxide anions, hydrogen peroxide and protein carbonyls in the foot and hepatopancreas of snails after 2 and 4 weeks of treatment. The studied antioxidant responses appeared largely to be tissue and remediation process specific, while the concentrations of superoxide anions, hydrogen peroxide and protein carbonyls depended on time of exposure, tissue type and the type of contaminants, but mostly not on the remediation process. Generally, changes in the concentrations of superoxide anions, hydrogen peroxide and protein carbonyls in the hepatopancreas of snails seemed to be a suitable measure to assess the risk of animals exposed to soil contaminated with petroleum substances and used after many years of ageing and treatment with a microbial formulation.