Risk element accumulation in Coleoptera and Hymenoptera (Formicidae) living in an extremely contaminated area-a preliminary study.

Abstract

The risk element accumulation ability of two groups of epigeic species, insects from families Coleoptera and Hymenoptera (namely Formicidae), was determined and related to soil risk element content and bioaccessibility. The study was conducted in the district of Příbram, Czech Republic, which was characterised by extremely high aged pollution in the soils, including risk elements, especially As, Pb, Zn and Cd, due to the former mining and smelting activity. Four sampling sites differing in their pseudo-total risk element contents were selected and composite samples of individuals representing either Coleoptera or Formicidae were sampled at the individual sampling points. The results indicate the ability of Coleoptera and Formicidae organisms to accumulate risk elements, especially at the location with extremely high soil risk element content. In soil containing up to 841mg As kg-1, 84.6mg Cd kg-1, 4250mg Pb kg-1 and 8542mg Zn kg-1, contents in insect bodies reached 239mg As kg-1 As, 24.2mg Cd kg-1, 70.4mg Pb kg-1 and 335mg Zn kg-1 in beetles and up to 20.9mg As kg-1, 29.9mg Cd kg-1, 111mg Pb kg-1 and 657mg Zn kg-1 in ants. Therefore, bioaccumulation factors (BAFs) varied between 0.02 and 0.55. Increasing Cd content in Coleoptera bodies with increasing soil pseudo-total element content was observed only among the investigated elements. However, the results indicate increasing BAF values with decreasing soil element levels, especially for Cd, Pb and Zn, indicating limited uptake of elements by the organisms living in contact with extremely contaminated soil.