The effects of lead and cadmium on earthworm Eisenia fetida growth, reproduction and survival were evaluated following the OECD earthworm acute and reproduction toxicity protocols. The range of the test concentrations of Pb (20–2500 μgPb g^–1 of soil) and Cd (1–100 μgCd g^–1 of soil) was chosen to simulate the levels that are likely to occur in the environment under different scenarios (typical soil levels, levels in industrial or urbanized contaminated soil). Worms were exposed for 28 days to a single metal in standard OECD artificial soil, and the LC₅₀ values for lead and cadmium could not be determined at the concentration ranges used. The risk of death of E. fetida increased with the concentration of lead (χ² = 28.64, p = 0.00001), though there was no significant mortality at all Cd concentrations. The weight of earthworms declined in all treatments during the experiment. Earthworms’ weight negatively correlated with lead concentrations in soil (14 days: R² = 0.59; 21 days: R² = 0.58; 28 days: R² = 0.62; p < 0.05). The weight of the earthworms exposed to cadmium tended to show a dose-related decrease, although a statistically significant decline was detected only in case of the highest concentration (100 μgCd g^–1 soil). Cocoon production was more sensitive than mortality and growth. A regression analysis showed that cocoon production rate significantly decreased with increasing lead concentration in soil (R² = 0.65, p = 0.0001) and the EC₅₀ value of 349 μgPb g^–1 was estimated. Cd inhibited the cocoon production rate by 18–65%.

Keywords: cadmium, earthworms, growth, lead, mortality, reproduction