Interspecies Variability of the Plant/Air Partitioning of Polychlorinated Biphenyls

• Published in: Environmental science & technology Vol. 31; no. 10; pp. 2944 - 2948
• Main Authors: Kömp, Peter, McLachlan, Michael S
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 01.10.1997
• Subjects: Air; Animal, plant and microbial ecology; Applied ecology; Biological and medical sciences; Ecotoxicology, biological effects of pollution; Effects of pollution and side effects of pesticides on plants and fungi; Environment; environmental degradation; Flowers & plants; Fundamental and applied biological sciences. Psychology; Grasses; Herbs; Non agrochemicals pollutants; PCB; Phytopathology. Animal pests. Plant and forest protection; plant ecology; pollution; Pollution effects and side effects of agrochemicals on crop plants and forest trees. Other anthropogenic factors; Pollution effects. Side effects of agrochemicals; Polychlorinated biphenyls; waste management; Central Europe; Europe; Grassland; Monocotyledones; Plantago lanceolata; Soil plant atmosphere relation; Interspecific comparison; Lolium multiflorum; Compositae; Polychlorobiphenyl; Crepis; Plantaginaceae; Pollutant; Leguminosae; Gramineae; Dicotyledones; Achillea millefolium; Angiospermae; Air pollution; Herbaceous plant; Spermatophyta; Fodder crop; Measurement method; Trifolium repens
• ISSN: 0013-936X; 1520-5851
• DOI: 10.1021/es970141+

The plant/air partition coefficients (K PA) of a range of PCB congeners were determined in five different grass and herb species common to Central Europe [ryegrass (Lolium multiflorum), clover (Trifolium repens), plantain (Plantago lanceolata), hawk's beard (Crepis biennis), and yarrow (Achil lea millefolium)]. The measurements were conducted between 10 and 35 °C using a solid-phase fugacity meter. Large differences in the partitioning behavior between the plants were observed, with the partition coefficient varying by up to a factor of 20 between the five species. There was also considerable interspecies variability in the enthalpy of phase change (plant to air), but these differences were not related to the differences in the partition coefficients. A good linear relationship between log K PA and experimentally determined log K OA values (octanol/air partition coef ficients) was obtained for each plant species (r  2 between 0.86 and 0.98). However, the slope of the regression lines ranged from 0.57 to 1.15. Using a solvent analogy, this indicates that the lipophilicity of the contaminant storage compartment is often different from octanol and varies widely among plants. The variability in the partition coefficients was primarily due to these differences in the quality of the lipophilic contaminant storage plant compartment, not to differences in its quantity or size. Most current models of organic contaminant accumulation in plants assume that the lipophilic storage compartment behaves like octanol, but this was not the case for any of the plants studied here. Before we can create models capable of accurately predicting concentrations of lipophilic trace organics in plants, more research into the nature of the plants' contaminant storage properties is necessary.