M8 AM Persistent Organic Pollutants
Monday, 14 November 2005: 8:00 AM - 11:40 AM in 337-338

(MAY-1117-720737) Diffusive mass transfer of 11 PAHs through different exposure media.

Mayer, P¹, Christensen, P^{1, 2}, Karlson, U¹, Reichenberg, F¹, Forbes, V², ¹ National Environmental Research Institute, Roskilde, Denmark² Roskilde University, Roskilde, Denmark

ABSTRACT- The biological uptake of hydrophobic organic compounds is often limited by the diffusive transport through a thin boundary layer. Therefore, a micro-scale technique was developed that quantifies mass transfer through a 100 micrometer thick layer of different exposure media. This technique has been applied to determine the diffusive mass transfer of 11 PAHs through water, air, digestive fluid of a deposit-feeding worm, aqueous soil extracts and solutions of surfactants. The diffusive flux of PAHs increases in the presence of, for instance, surfactants and digestive fluids. The enhancement factor increased with increasing molecular size of the PAHs, and the diffusive flux of benzo(a)pyrene was enhanced 71 times through gut fluid of a deposit-feeding worm when compared to water. The working principle of the new method will be presented along with the experimental results that have implications for (bio)availability and for comparing different exposure routes.

Key words: pah, diffusive mass transfer, exposure routes, hydrophobic organic chemicals