Contribution of ingestive/dietary uptake to bioaccumulation of organics in worms
Journal
Science of The Total Environment
Journal Volume
956
Start Page
177378
ISSN
0048-9697
Date Issued
2024-12-15
Author(s)
DOI
10.1016/j.scitotenv.2024.177378
Abstract
Ingestive uptake is critical for understanding the accumulation and trophic transfer of chemicals and synthesized particles in general. This study explored the contribution of ingestion in the bioaccumulation of chemicals focusing on worms. Novel theory and equations were developed to derive fractional ingestive contribution, fs, from a broad range of dietary uptake and accumulation studies, and to build a small dataset of fs (n = 43) from relevant toxicokinetic and bioaccumulation measurements. Worm fs could be fitted to log KOW-based sigmoidal models with small errors (RSE < 0.15, RMSE<0.15). The basis and limitations of the applied fs equations were elaborated. These included the assumption that aqueous-based and dietary-based elimination rate constants (kTw and kTS) may be statistically equivalent, as demonstrated using fish and worm data. Bioaccumulation and toxicokinetic parameters obtained at under-exposed conditions can also result in non-sensical, negative fs. The developed fs theory suggested a novel way to model bioaccumulation in the presence of aqueous and solid sources, and the potential to consolidate bioaccumulation data in their variant forms and definitions for assessment, modeling, and benchmarking purposes. While the presented fs-log KOW dependence remained to be explored in other species, the importance of ingestive uptake for high-log KOW chemicals questioned the validity of characterizing and regulating bioaccumulation potential of hydrophobic organics – for which dietary uptake matters – using aqueous-only bioconcentration factor (BCF). This question, along with other less important ones, is yet to be explored in future works.
Subjects
Bioaccumulation
Dietary uptake
Ecological risk assessment
Fractional contribution
Ingestion
Modeling
Uptake route
Publisher
Elsevier BV
Type
journal article