Effect of nonaqueous‐phase liquids on the availability of polycyclic aromatic hydrocarbons in soil for worm uptake and bacterial genotoxicity

Abstract

A study was conducted to determine the effect of nonaqueous-phase liquids (NAPLs) on the bioavailability of benzo[a]pyrene (BaP) in soil. Sentry 19 oil and pristane reduced the availability of BaP for assimilation by the earthworm Eisenia fetida and for mutagenicity in a rifampicin-sensitive strain of Pseudomonas putida. As much as 80% of the compound could be rendered unavailable to the worms or for genotoxicity. Tests with five alkanes and an oil showed that the extent of reduction in genotoxicity of BaP varied with the identity, viscosity, and hydrophobicity of the NAPL. The magnitude of the decline in availability for genotoxicity differed in tests of three soils. Because little or no BaP was lost from the soil, the diminished bioavailability was not the result of a diminished total concentration of the compound. These findings show that exposure to hydrophobic toxicants can be appreciably altered in soils containing NAPLs.

Effects of aging and mixed nonaqueous‐phase liquid sources in soil systems on earthworm bioaccumulation, microbial degradation, sequestration, and aqueous desorption of pyrene

“…The substantial decrease of pyrene accumulation by earthworms in the presence of NAPL is similar to what was observed for benzo [a]pyrene in soils in the presence of pristane or Sentry 19 oil [18]. The body burden values provided can readily be converted to bioaccumulation factors given the high pyrene recovery or biota-soil accumulation factor values using organic carbon values provided in the Methods section and an estimate of 2.0% lipid content determined in our laboratory previously [35].…”

“…Nonaqueous-phase liquids also enter and occupy pores in soil particles. Small micropore diameters and tortuous diffusion paths may in such cases constrain diffusion and in turn significantly limit mass transfer of associated HOC contaminants into soil pore water, thus diminishing contaminant availabilities to soil organisms [13,[18][19][20] For example, uptake of benzo [a]pyrene by earthworms (Eisenia fetida) has been reported to decrease in the presence of NAPLs [18]; however, effects of aging in the presence of the NAPLs were not investigated. Nonaqueous-phase liquids also may impact degradation of associated HOC contaminants through enzyme inhibition, membrane modification, extraction of cell wall components, or coating of cells by organic phases [21].…”

TOXICITY AND TOXICOKINETICS OF BINARY COMBINATIONS OF PETROLEUM HYDROCARBON DISTILLATES WITH THE EARTHWORM EISENIA ANDREI

“…Presence of a NAPL can lead to a decrease in the bioavailability of compounds to earthworms , as observed in the present study. The observed decrease in the accumulation of F2 in the presence of F3a (Fig.…”

Residue Analysis of Organochlorine and Organophosphorus Pesticides in Urban Lake Sediments

“…A precise determination of hydrocarbon effects on species is limited by the uncertainty in the quantification of receptor exposure (Quiñones-Rivera et al, 2003). The ecological risk analysis based on the amount of hydrocarbons does not necessarily indicate how much is available for absorption by the living organisms (Semple et al, 2004).…”