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Bioavailability of the organophosphorous insecticide chlorpyrifos to the suspension‐feeding bivalve, Mercenaria mercenaria , following exposure to dissolved and particulate matter
Author(s) -
Bejarano Adriana C.,
Widenfalk Anneli,
Decho Alan W.,
Chandler G. Thomas
Publication year - 2003
Publication title -
environmental toxicology and chemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.1
H-Index - 171
eISSN - 1552-8618
pISSN - 0730-7268
DOI - 10.1897/02-293
Subject(s) - mercenaria , environmental chemistry , particulates , bioavailability , chemistry , estuary , microcosm , microplastics , bivalvia , ecology , biology , mollusca , bioinformatics , organic chemistry
Under estuarine conditions, hydrophobic, hydrophobic pesticides physical/chemical partitioning into dissolved and particulate fractions of sediments. Our experimental study using 14 C‐chlorpyrifos ( 14 C‐CHPY) showed that sorptive associations of this common insecticide with particulate (>0.2 μm) and dissolved fractions (<0.2 μm) of sediments strongly influenced uptake, tissue absorption, and elimination in the estuarine bivalve Mercenaria mercenaria. Bivalves were fed algae mixed with particulate and dissolved fractions of 14 C‐CHPY‐contaminated estuarine sediment particles, components of estuarine sediments (silica, humic acids), and a naturally occurring food source (phytoplankton) to quantify relative uptake, tissue absorption efficiencies, and elimination of 14 C‐CHPY. Measurements of 14 C‐CHPY tissue absorption efficiencies (AE%) indicated that particle source qualities influenced much of the insecticide bioavailability. Mean tissue AE% of 14 C‐CHPY associated with different particulate fractions ranged from 23 to 31%, while uptake from the dissolved/colloidal forms resulted in low (7‐17%) AE%. Our data indicated that 14 C‐CHPY is more likely to bioaccumulate through ingestion of contaminated particulate material than through filtration/ingestion of dissolved/colloidal material. The high selectivity and digestibility of algae particles by M. mercenaria , a potentially ingested food source, may play an important role in the bioavailability of chlorpyrifos in this animal.