Background and purpose: Increasing entry of heavy metals into the environment and its effects on social structure of soil organisms disturbs the soil ecosystem. Study of molecular and cellular soil invertebrate responses as biomarkers of environmental health can provide useful information in relation to the effect of pollutants on them. Accordingly the aim of this research was to study the effects of cadmium and lead on Biomass, lipid peroxidation (LPo) and total antioxidant capacity (TAC), as cell physiology markers, in Eisenia fetida earthworm.

Materials and methods: In this study, acute toxicity test was carried out according to the Organization for Economic Co-Operation and Development (OECD) guidelines (NO 207). TAC and LPo levels were assayed by ferric reducing antioxidant power and thiobarbituric acid methods, respectively.

Results: LC₅₀ as a viability marker, for Cd and Pb (µg/cm²) were 54.84 and 14.18 in 24h, and 34.1 and 8.4 in 48h, respectively. By increase in concentrations of lead and cadmium the rate of mortality, weight loss, LPo and TAC increased. E. fetida was found to be more sensitive to Cd than Pb (P<0.05).

Conclusion: According to the results, in presence of lead and cadmium LPo and TAC increase significantly in E. fetida earthworm. Therefore, measurement of MDA and TAC as cell physiology markers could be used to evaluate the sensitivity of E. fetida earthworm to Cd and Pb in management of pollution resources and environmental health.