Accumulation and elimination of 16 polycyclic aromatic compounds in the earthworm ( Eisenia fetida )

Acumulation and elimination of different polycyclic aromatic compounds (PACs) were studied in earthworms ( Eisenia fetida ) exposed to contaminated soil from an old gasworks site. In total, 12 polycyclic aromatic hydrocarbons (PAHs), two N ‐ and S ‐heterocyclic PACs, and two PAC‐quinones were included in the study. Peak‐shaped accumulation curves were found for many of the compounds. After 19 d of exposure, the ratio between concentrations in worm lipids and soil organic matter was 0.02 on average. The half‐lives of the PACs were relatively long, between 2 and 11d. The elimination rate constants, k 2 , correlated both with literature‐derived octanol‐water partition coefficients ( K ow ) for PAHs ( r 2 = 0.93) and the computed polarizability ( r 2 = 0.88) of all the compounds. The elimination rate constants of PAHs are comparable to those of PCBs found in earlier studies, and the linear regression coefficient, r 2 , of k 2 against K ow for PAHs and PCBs together was 0.93.