QSARs for KOW and KOC of PCB congeners : A critical examination of data, assumptions and statistical approaches

The form and bioavailability of non-ionic organic chemicals in sewage sludge-amended agricultural soils.

Studies on the fate and effects of organic pollutants in soil and sediment are often carried out under laboratory conditions and often require the study compound to be introduced, or spiked, into the test substrate. The procedures adopted to spike relatively large amounts of hydrophobic organic compounds into soil and sediment can introduce interferences into experiments that have the potential to dominate the process(es) under investigation. This review identifies and discusses key factors of spiking procedures that can introduce significant interferences to experiments. These include soil or sediment drying and rewetting, effects of carrier solvents, and the homogeneity of spike distribution. The persistence of solvents, and therefore their contribution to soil and sediment organic carbon, is discussed with reference to potential effects on the partitioning behavior of spiked compounds. We have summarized the spiking procedures used in 64 published articles and have evaluated the information supplied by authors. From this analysis, we conclude that, in general, authors should report more detailed information regarding the procedural aspects of compound spiking. We conclude that standard operating procedures need to be validated and recommended for spiking organic compounds into soil and sediment by recommended organizations. As an aid to this process, we recommend a number of practices to observe when spiking organic compounds into soil and sediment.

Spiking hydrophobic organic compounds into soil and sediment : a review and critique of adopted procedures.

The purpose of this study was to assess the suitability of various spiking procedures for the introduction of persistent organic pollutants (POPs) into soil environments. 14C-radiolabeled analogues of two representative polycyclic aromatic hydrocarbons (PAHs), phenanthrene (Phe), and benzo[a]pyrene (B[a]P), were introduced into soil using different spiking techniques, and the homogeneity of compound distribution in subsamples was assessed. It was established that under analogous spiking procedures dry soil could be spiked with greater homogeneity than wet soil. The procedure which gave the most homogeneous distribution of compound involved a single spiking/rehydration operation conducted on dry soil. Relative standard deviations of 2.40% for 14C-9-Phe and 3.65% for 14C-7-B[a]P were obtained for this procedure. An optimum procedure for the spiking of wet soil was established, giving relative standard deviations of 4.1% for 14C-9-Phe and 3.7% for 14C-7-B[a]P. This procedure employed a highly spiked wet soil...

Evaluation of Spiking Procedures for the Introduction of Poorly Water Soluble Contaminants into Soil

Ecological effects of Irgarol 1051 and Diuron on a coastal meiobenthic community: A laboratory microcosm experiment

The earthworm's (Lumbricus rubellus) uptake of polychlorinated biphenyls (PCBs) from a soil contaminated with a commercial PCB formulation (Askarel at 150 μg g−1) and their elimination of PCBs into a low contaminated soil (15 μg g−1) has been studied. 17 individual congeners were monitored. The uptake and the elimination rate were similar for all PCB congeners notwithstanding their different chloro-substitution pattern which suggested that bioaccumulation of PCBs in earthworms is governed by passive, possibly diffusion controlled processes. The equilibrium state in the three-phase system, soil/soil water/earthworm was reached with a half-time around 3–4 days. The soil to earthworm bioconcentration factor ranged from 4 to 20 for tetra- to octa-chlorinated biphenyls and was weakly depending on the octanol-water partition coefficient: BCF = −(1.3−1.8) × K OW (0.35−0.40).

F. Pelusio

Papers

Bio Availability of Polychlorinated Biphenyl Congeners in the Soil to Earthworm (L. rubellus) System