Does equilibrium passive sampling reflect actual in situ bioaccumulation of PAHs and petroleum hydrocarbon mixtures in aquatic worms?

Over the past couple of years, several analytical methods have been developed for assessing the bioavailability of environmental contaminants in sediments and soils. Comparison studies suggest that equilibrium passive sampling methods generally provide the better estimates of internal concentrations in organisms and thus of subsequent risks. However, field studies to validate the potential of passive sampling to predict actual in situ bioaccumulation are scarce and limited information only exists on selected, individual compounds.

Assessing the bioavailability of complex petroleum hydrocarbon mixtures in sediments.

Several experimental methods have been developed to assess the bioavailability of individual organic compounds. So far none of them has however been applied to complex mixtures, such as oil (petroleum hydrocarbons), which is an ubiquitous pollutant. In the present study, we tested the potential of five of these experimental methods and that of a model approach to predict bioaccumulation of oil in the aquatic worm Lumbriculus variegatus exposed to 14 field-contaminated sediments.

A closer look at bioaccumulation of petroleum hydrocarbon mixtures in aquatic worms.

Petroleum hydrocarbons (oils) are ubiquitous in the aquatic environment, and adequate risk assessment is thus essential. Bioaccumulation plays a key role in risk assessment, but the current knowledge on bioaccumulation of oils is limited. Therefore, this process was studied in detail, using the aquatic worm, Lumbriculus variegatus, and 14 field-contaminated sediments.

Using solid phase micro extraction to determine salting-out (Setschenow) constants for hydrophobic organic chemicals.

With increasing ionic strength, the aqueous solubility and activity of organic chemicals are altered. This so-called salting-out effect causes the hydrophobicity of the chemicals to be increased and sorption in the marine environment to be more pronounced than in freshwater systems. The process can be described with empirical salting-out or Setschenow constants, which traditionally are determined by comparing aqueous solubilities in freshwater and saline water.

Temperature-dependent bioaccumulation of polycyclic aromatic hydrocarbons.

Bioaccumulation factors (BAFs) play a key role in risk assessment of chemicals in sediments and soils. For hydrophobic organic chemicals (HOCs), BAFs are, however, difficult to determine and values are mostly obtained by modeling. Apart from a lack of reliable data, the applicability of lab-derived values in the field situation is unknown, as exposure conditions (e.

Evaluation of clean-up agents for total petroleum hydrocarbon analysis in biota and sediments.

Petroleum hydrocarbons (oil) are common environmental contaminants. For risk assessment purposes, their concentrations in environmental matrixes, such as biota and soils/sediments are frequently determined by solvent extraction and subsequent analysis with gas chromatography (GC) equipped with flame ionization detection (FID) or mass spectrometry (MS). Because the total GC detector response is labeled as total petroleum hydrocarbon (TPH) concentration and matrix compounds (lipids, organic matter) will contribute to this response, proper extract clean-up is crucial.