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Effects of C₆₀ exposure (0, 15 or 154 mg/kg soil) on the earthworm Lumbricus rubellus were assessed at the tissue and molecular level, in two experiments. In the first experiment, earthworms were exposed for four weeks, and in the second lifelong. In both experiments, gene expression of heat shock protein 70 (HSP70) decreased. For catalase and glutathione-S-transferase (GST), no significant trends in gene expression or enzyme activity were observed. Gene expression of coelomic cytolytic factor-1 (CCF-1) did not alter in earthworms exposed for four weeks, but was significantly down-regulated in the lifelong exposure. Histology of earthworms exposed to C₆₀ in both experiments showed a damaged cuticle, with underlying pathologies of epidermis and muscles, as well as effects on the gut barrier. However, tissue repair was also observed in these earthworms. Overall, these data show that sub-lethal C₆₀ exposure to earthworms via the soil affects gene expression and causes tissue pathologies.

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Many soils are polluted with mixtures of moderate levels of contaminants. In The Netherlands 175,000 sites in rural areas are classified as highly polluted. However, it remains unclear to what extent local ecosystems are endangered. In this paper, we report on the effect of contaminants on earthworms in a meadow system. We tested a polluted and a reference field soil with similar soil characteristics and agricultural use. In the polluted soil copper, mercury, and lead were elevated by more than 200% compared with the reference soil. Bioassays on growth and reproduction in the earthworm species Lumbricus rubellus were executed in both soils, and a population model was used to assess the population-level consequences of changes in growth and reproduction. No significant effects were seen on reproduction and survival in L. rubellus, but development was retarded in the polluted soil. This resulted in a 23% lower growth rate and a change in demography toward younger individuals. Field data on population composition of earthworms were used to support the laboratory results, and the relevance of the results for the godwit (Limosa limosa), which mainly feeds on earthworms during the breeding season, is discussed.