Toxicity of Graphite Flakes in Soil to Earthworms

Graphite flakes, a potential candidate for use in various military hardware and equipment, were tested for their toxicity to the earthworm Eisenia foetida. The graphite flakes were tested at 0 control, 0.05, 0.10, 0.50, and 1.00 concentrations by weight. These concentrations were used in the study by thoroughly incorporating the graphite flakes into an artificial soil mixture composed of sphagnum peat 10, kaolinite clay 20, fine sand 69, and calcium carbonate 1. Graphite flakes produced no lethal effects at graphite flake concentrations up to 1.0. Sublethal effects, measures as weight changes, ranged from net increases of 27.4 to 29.5. The results indicate that graphite flakes are not toxic to earthworms E. foetida at the concentrations tested. Keywords Artificial soil, Sublethal effects.