ECOTOXIC ASSESSMENT OF SOILS CONTAMINATED WITH MUNICIPAL WASTE FROM A DUMP IN Eisenia fetida

Abstract

An ecotoxic evaluation of soils contaminated with municipal waste from a dump in Eisenia fetida (Savigny, 1826) was carried out. The earthworm E. fetida was exposed to five soil samples contaminated by municipal waste from the Pampa Calanguillo landfill, Lima, Peru. Each sample was evaluated in six concentrations: 0.39%, 0.78%, 1.56%, 3.13%, 6.25% and 12.50%, and in a control treatment that corresponded to an artificial soil for evaluate its ecotoxic effect. The lethal effect evaluated was lethality, and the sublethal effects were five: fragmentation, thinning, darkening, mean weight and mean length at 7 and 14 days of exposure. The soils were evaluated for their physical-chemical properties, heavy metals and hydrocarbons. The soils presented lethal toxicity effects based on the mean lethal concentration (LC₅₀) in E. fetida, where the level of affectation prevailed in the soils with the highest presence of metals and hydrocarbons. The most frequent sublethal effects were thinning and mean wet and dry weight, while fragmentation and darkening were evident in the highest concentrations. The mean length reduction mostly did not show significant differences between the concentrations used. It is concluded that there is a lethal and sublethal ecotoxic effect in E. fetida in soils contaminated by municipal waste. Evidence suggests that municipal waste disposed of in landfills are sources of soil quality degradation and therefore represent an ecological risk for biota.