How important is feeding to the bioaccumulation of organic chemicals in worms?

Research output: Conference Papers (RGC: 31A, 31B, 32, 33)32_Refereed conference paper (no ISBN/ISSN)peer-review

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Original languageEnglish
Publication statusPublished - 2014

Abstract

Until now, bioaccumulation of organic chemicals in worms has been modeled mostly by equilibrium partitioning or simple logKOW-based empirical relationships, and a mechanistic account of the phenomenon has yet to be developed. This stagnant situation can be largely attributed to two major modeling challenges: dietary uptake and in vivo biotransformation. This study focuses on the dietary uptake of organic chemicals in worms. First, the theoretical foundation for separating uptake contribution due to feeding and interstitial water exposure was developed. The uptake contribution due to feeding or aqueous exposure can be extracted from bioaccumulation experiments through different approaches. These approaches will be demonstrated using experimental data from existing literature. Following the developed methodology, an accurate correlation was developed for the fractional contribution of feeding to overall chemical uptake, fs, in worms based on extracted data following a rigorous review process (RMSE = 0.12; logKOW from 0.87 to 8.2; n = 28). The extracted data clearly demonstrates the dominance of feeding in the bioaccumulation of organic chemicals with logKOW ≥ 5. Finally, how the developed fs correlation may be used to develop a generic dietary uptake model for worms is demonstrated using apparent dietary uptake rate constants extracted from reviewed experimental literature (n = 68). The results from this study will bring us a step closer towards using worm as a representative sentinel organism in terrestrial and benthic ecosystems. Limitations of the current study will be briefly discussed.