WP7 Bioavailability in Sediments / Water
Wednesday, 16 November 2005: 8:00 AM - 6:30 PM in Exhibit Hall

(QUI-1117-661638) A study of the effects of nonaqueous-phase liquids (NAPLs) on the bioavailability of pyrene to worms.

Quiñones-Rivera, A^{1, 2}, Alexander, M¹, ¹ Cornell University, Ithaca, NY, USA² Syracuse Research Corporation, Syracuse, NY, USA

ABSTRACT- Polluting hydrophobic organic compounds (HOCs) frequently enter terrestrial and aquatic environments as nonaqueous-phase liquids (NAPLs). Sources of NAPLs include leaks from underground storage tanks, surface spills, and inappropriate disposal practices. Although a number of studies have examined the effect of NAPLs on the availability of HOCs to bacteria, there is a paucity of data regarding the effect of NAPLs on the availability of HOCs to aquatic or terrestrial invertebrates. Work in our laboratory showed that the bioavailability of benzo(a)pyrene in soil for uptake by the worm Eisenia fetida was significantly lower when the polycyclic aromatic hydrocarbon (PAH) was dissolved in a lubricating oil or pristane than when it was added to soil alone. We present here the results of a study of the effect of NAPLs on the bioavailability of aged or unaged pyrene in soil. Uptake of pyrene by E. fetida was lower when the PAH was added to soil in pristane, dodecane, tetradecane, hexadecane, or a series of lubricating oils than when the aromatic hydrocarbon was added to soil alone. The reduction in uptake was not attributable to reduced feeding by the worms. Aging pyrene in soil significantly reduced its uptake by E. fetida; however, there was no reduction in the availability of pyrene to worms when the PAH was added to soil in a NAPL and aged for up to 105 days. Increasing the amount of NAPL in which pyrene was dissolved generally resulted in significant reductions in pyrene uptake. This study provides additional evidence that the presence of NAPLs in soil may significantly affect the bioavailability of organic compounds to soil invertebrates. The data suggest that although NAPLs may reduce the short-term bioavailability of HOCs to soil invertebrates, they may also abolish the expected time-dependent reduction in bioavailability of HOCs aged in soil.

Key words: Bioavailability, Pyrene, Nonaqueous-Phase Liquids