Earthworms (Oligochaeta: Lumbricidae) and heavy metals: content and bioaccumulation in the body

Abstract

Nowadays, when one of the most significant problems for mankind is saving the soil from pollution. It is well-known that one of the most important means of soil rehabilitation and remediation are soil inhabitants, their biodiversity and products of their life activity. Given the significant role of soil inhabitants in soil formation processes, it is important to consider their role in the processes of reprocessing and bioaccumulation of heavy metals. That especially concerns the earthworms, whose role in soil formation and maintenance of natural fertility is well-known and causes the interest of soil scientists and ecologists. The paper shows the degree of bioaccumulation of heavy metals (copper, zinc and lead) in the body of earthworms. Study involved three species of earthworms, which were collected in the vicinity of Tbilisi – Aporrectodea rosea (Savigny, 1826), Eisenia veneta (Rosa, 1886) and Allolobophora chlorotica (Savigny, 1826) – showed that earthworms of different species accumulate different amounts of heavy metals – copper, zinc and lead and, depending on the species, after being placed in heavy metals solutions, they demonstrate the different intensity of movement. The amount of heavy metals in the body of an earthworm depends on the structure of the body tissues and maybe on the structure of the skin- muscular sac.